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-rw-r--r--contrib/libpng/pngvalid.c6658
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diff --git a/contrib/libpng/pngvalid.c b/contrib/libpng/pngvalid.c
deleted file mode 100644
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--- a/contrib/libpng/pngvalid.c
+++ /dev/null
@@ -1,6658 +0,0 @@
-
-/* pngvalid.c - validate libpng by constructing then reading png files.
- *
- * Last changed in libpng 1.5.1 [February 3, 2011]
- * Copyright (c) 2011 Glenn Randers-Pehrson
- * Written by John Cunningham Bowler
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * NOTES:
- * This is a C program that is intended to be linked against libpng. It
- * generates bitmaps internally, stores them as PNG files (using the
- * sequential write code) then reads them back (using the sequential
- * read code) and validates that the result has the correct data.
- *
- * The program can be modified and extended to test the correctness of
- * transformations performed by libpng.
- */
-
-#include "png.h"
-#if PNG_LIBPNG_VER < 10500
-/* This delibarately lacks the PNG_CONST. */
-typedef png_byte *png_const_bytep;
-
-/* This is copied from 1.5.1 png.h: */
-#define PNG_INTERLACE_ADAM7_PASSES 7
-#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7)
-#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7)
-#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
-#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
-#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
- -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
-#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
- -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
-#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
- (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
-#define PNG_COL_FROM_PASS_COL(xIn, pass) \
- (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
-#define PNG_PASS_MASK(pass,off) ( \
- ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \
- ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U))
-#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
- ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
-#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
- ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
-
-/* These are needed too for the defualt build: */
-#define PNG_WRITE_16BIT_SUPPORTED
-#define PNG_READ_16BIT_SUPPORTED
-#endif
-
-#include "zlib.h" /* For crc32 */
-
-#include <float.h> /* For floating point constants */
-#include <stdlib.h> /* For malloc */
-#include <string.h> /* For memcpy, memset */
-#include <math.h> /* For floor */
-
-/* Unused formal parameter errors are removed using the following macro which is
- * expected to have no bad effects on performance.
- */
-#ifndef UNUSED
-# if defined(__GNUC__) || defined(_MSC_VER)
-# define UNUSED(param) (void)param;
-# else
-# define UNUSED(param)
-# endif
-#endif
-
-/***************************** EXCEPTION HANDLING *****************************/
-#include "contrib/visupng/cexcept.h"
-struct png_store;
-define_exception_type(struct png_store*);
-
-/* The following are macros to reduce typing everywhere where the well known
- * name 'the_exception_context' must be defined.
- */
-#define anon_context(ps) struct exception_context *the_exception_context = \
- &(ps)->exception_context
-#define context(ps,fault) anon_context(ps); png_store *fault
-
-/******************************* UTILITIES ************************************/
-/* Error handling is particularly problematic in production code - error
- * handlers often themselves have bugs which lead to programs that detect
- * minor errors crashing. The following functions deal with one very
- * common class of errors in error handlers - attempting to format error or
- * warning messages into buffers that are too small.
- */
-static size_t safecat(char *buffer, size_t bufsize, size_t pos,
- PNG_CONST char *cat)
-{
- while (pos < bufsize && cat != NULL && *cat != 0)
- buffer[pos++] = *cat++;
-
- if (pos >= bufsize)
- pos = bufsize-1;
-
- buffer[pos] = 0;
- return pos;
-}
-
-static size_t safecatn(char *buffer, size_t bufsize, size_t pos, int n)
-{
- char number[64];
- sprintf(number, "%d", n);
- return safecat(buffer, bufsize, pos, number);
-}
-
-static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d,
- int precision)
-{
- char number[64];
- sprintf(number, "%.*f", precision, d);
- return safecat(buffer, bufsize, pos, number);
-}
-
-static PNG_CONST char invalid[] = "invalid";
-static PNG_CONST char sep[] = ": ";
-
-/* NOTE: this is indexed by ln2(bit_depth)! */
-static PNG_CONST char *bit_depths[8] =
-{
- "1", "2", "4", "8", "16", invalid, invalid, invalid
-};
-
-static PNG_CONST char *colour_types[8] =
-{
- "greyscale", invalid, "truecolour", "indexed-colour",
- "greyscale with alpha", invalid, "truecolour with alpha", invalid
-};
-
-/* To get log-bit-depth from bit depth, returns 0 to 7 (7 on error). */
-static unsigned int
-log2depth(png_byte bit_depth)
-{
- switch (bit_depth)
- {
- case 1:
- return 0;
-
- case 2:
- return 1;
-
- case 4:
- return 2;
-
- case 8:
- return 3;
-
- case 16:
- return 4;
-
- default:
- return 7;
- }
-}
-
-/* A numeric ID based on PNG file characteristics. The 'do_interlace' field
- * simply records whether pngvalid did the interlace itself or whether it
- * was done by libpng. Width and height must be less than 256.
- */
-#define FILEID(col, depth, interlace, width, height, do_interlace) \
- ((png_uint_32)((col) + ((depth)<<3) + ((interlace)<<8) + \
- (((do_interlace)!=0)<<15) + ((width)<<16) + ((height)<<24)))
-
-#define COL_FROM_ID(id) ((png_byte)((id)& 0x7U))
-#define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU))
-#define INTERLACE_FROM_ID(id) ((int)(((id) >> 8) & 0x3))
-#define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1))
-#define WIDTH_FROM_ID(id) (((id)>>16) & 0xff)
-#define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff)
-
-/* Utility to construct a standard name for a standard image. */
-static size_t
-standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type,
- int log_bit_depth, int interlace_type, png_uint_32 w, png_uint_32 h,
- int do_interlace)
-{
- pos = safecat(buffer, bufsize, pos, colour_types[colour_type]);
- pos = safecat(buffer, bufsize, pos, " ");
- pos = safecat(buffer, bufsize, pos, bit_depths[log_bit_depth]);
- pos = safecat(buffer, bufsize, pos, " bit ");
-
- if (interlace_type != PNG_INTERLACE_NONE)
- pos = safecat(buffer, bufsize, pos, "interlaced");
- if (do_interlace)
- pos = safecat(buffer, bufsize, pos, "(pngvalid)");
- else
- pos = safecat(buffer, bufsize, pos, "(libpng)");
- if (w > 0 || h > 0)
- {
- pos = safecat(buffer, bufsize, pos, " ");
- pos = safecatn(buffer, bufsize, pos, w);
- pos = safecat(buffer, bufsize, pos, "x");
- pos = safecatn(buffer, bufsize, pos, h);
- }
-
- return pos;
-}
-
-static size_t
-standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id)
-{
- return standard_name(buffer, bufsize, pos, COL_FROM_ID(id),
- log2depth(DEPTH_FROM_ID(id)), INTERLACE_FROM_ID(id),
- WIDTH_FROM_ID(id), HEIGHT_FROM_ID(id), DO_INTERLACE_FROM_ID(id));
-}
-
-/* Convenience API and defines to list valid formats. Note that 16 bit read and
- * write support is required to do 16 bit read tests (we must be able to make a
- * 16 bit image to test!)
- */
-#ifdef PNG_WRITE_16BIT_SUPPORTED
-# define WRITE_BDHI 4
-# ifdef PNG_READ_16BIT_SUPPORTED
-# define READ_BDHI 4
-# define DO_16BIT
-# endif
-#else
-# define WRITE_BDHI 3
-#endif
-#ifndef DO_16BIT
-# define READ_BDHI 3
-#endif
-
-static int
-next_format(png_bytep colour_type, png_bytep bit_depth)
-{
- if (*bit_depth == 0)
- {
- *colour_type = 0, *bit_depth = 1;
- return 1;
- }
-
- *bit_depth = (png_byte)(*bit_depth << 1);
-
- /* Palette images are restricted to 8 bit depth */
- if (*bit_depth <= 8
-# ifdef DO_16BIT
- || (*colour_type != 3 && *bit_depth <= 16)
-# endif
- )
- return 1;
-
- /* Move to the next color type, or return 0 at the end. */
- switch (*colour_type)
- {
- case 0:
- *colour_type = 2;
- *bit_depth = 8;
- return 1;
-
- case 2:
- *colour_type = 3;
- *bit_depth = 1;
- return 1;
-
- case 3:
- *colour_type = 4;
- *bit_depth = 8;
- return 1;
-
- case 4:
- *colour_type = 6;
- *bit_depth = 8;
- return 1;
-
- default:
- return 0;
- }
-}
-
-static unsigned int
-sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth,
- png_uint_32 x, unsigned int sample_index)
-{
- png_uint_32 bit_index, result;
-
- /* Find a sample index for the desired sample: */
- x *= bit_depth;
- bit_index = x;
-
- if ((colour_type & 1) == 0) /* !palette */
- {
- if (colour_type & 2)
- bit_index *= 3;
-
- if (colour_type & 4)
- bit_index += x; /* Alpha channel */
-
- if (colour_type & (2+4))
- bit_index += sample_index * bit_depth; /* Multiple channels: select one */
- }
-
- /* Return the sample from the row as an integer. */
- row += bit_index >> 3;
- result = *row;
-
- if (bit_depth == 8)
- return result;
-
- else if (bit_depth > 8)
- return (result << 8) + *++row;
-
- /* Less than 8 bits per sample. */
- bit_index &= 7;
- return (result >> (8-bit_index-bit_depth)) & ((1U<<bit_depth)-1);
-}
-
-/* Copy a single pixel, of a given size, from one buffer to another -
- * while this is basically bit addressed there is an implicit assumption
- * that pixels 8 or more bits in size are byte aligned and that pixels
- * do not otherwise cross byte boundaries. (This is, so far as I know,
- * universally true in bitmap computer graphics. [JCB 20101212])
- *
- * NOTE: The to and from buffers may be the same.
- */
-static void
-pixel_copy(png_bytep toBuffer, png_uint_32 toIndex,
- png_const_bytep fromBuffer, png_uint_32 fromIndex, unsigned int pixelSize)
-{
- /* Assume we can multiply by 'size' without overflow because we are
- * just working in a single buffer.
- */
- toIndex *= pixelSize;
- fromIndex *= pixelSize;
- if (pixelSize < 8) /* Sub-byte */
- {
- /* Mask to select the location of the copied pixel: */
- unsigned int destMask = ((1U<<pixelSize)-1) << (8-pixelSize-(toIndex&7));
- /* The following read the entire pixels and clears the extra: */
- unsigned int destByte = toBuffer[toIndex >> 3] & ~destMask;
- unsigned int sourceByte = fromBuffer[fromIndex >> 3];
-
- /* Don't rely on << or >> supporting '0' here, just in case: */
- fromIndex &= 7;
- if (fromIndex > 0) sourceByte <<= fromIndex;
- if ((toIndex & 7) > 0) sourceByte >>= toIndex & 7;
-
- toBuffer[toIndex >> 3] = (png_byte)(destByte | (sourceByte & destMask));
- }
- else /* One or more bytes */
- memmove(toBuffer+(toIndex>>3), fromBuffer+(fromIndex>>3), pixelSize>>3);
-}
-
-/* Compare pixels - they are assumed to start at the first byte in the
- * given buffers.
- */
-static int
-pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width)
-{
- if (memcmp(pa, pb, bit_width>>3) == 0)
- {
- png_uint_32 p;
-
- if ((bit_width & 7) == 0) return 0;
-
- /* Ok, any differences? */
- p = pa[bit_width >> 3];
- p ^= pb[bit_width >> 3];
-
- if (p == 0) return 0;
-
- /* There are, but they may not be significant, remove the bits
- * after the end (the low order bits in PNG.)
- */
- bit_width &= 7;
- p >>= 8-bit_width;
-
- if (p == 0) return 0;
- }
-
- return 1; /* Different */
-}
-
-/*************************** BASIC PNG FILE WRITING ***************************/
-/* A png_store takes data from the sequential writer or provides data
- * to the sequential reader. It can also store the result of a PNG
- * write for later retrieval.
- */
-#define STORE_BUFFER_SIZE 500 /* arbitrary */
-typedef struct png_store_buffer
-{
- struct png_store_buffer* prev; /* NOTE: stored in reverse order */
- png_byte buffer[STORE_BUFFER_SIZE];
-} png_store_buffer;
-
-#define FILE_NAME_SIZE 64
-
-typedef struct png_store_file
-{
- struct png_store_file* next; /* as many as you like... */
- char name[FILE_NAME_SIZE];
- png_uint_32 id; /* must be correct (see FILEID) */
- png_size_t datacount; /* In this (the last) buffer */
- png_store_buffer data; /* Last buffer in file */
-} png_store_file;
-
-/* The following is a pool of memory allocated by a single libpng read or write
- * operation.
- */
-typedef struct store_pool
-{
- struct png_store *store; /* Back pointer */
- struct store_memory *list; /* List of allocated memory */
- png_byte mark[4]; /* Before and after data */
-
- /* Statistics for this run. */
- png_alloc_size_t max; /* Maximum single allocation */
- png_alloc_size_t current; /* Current allocation */
- png_alloc_size_t limit; /* Highest current allocation */
- png_alloc_size_t total; /* Total allocation */
-
- /* Overall statistics (retained across successive runs). */
- png_alloc_size_t max_max;
- png_alloc_size_t max_limit;
- png_alloc_size_t max_total;
-} store_pool;
-
-typedef struct png_store
-{
- /* For cexcept.h exception handling - simply store one of these;
- * the context is a self pointer but it may point to a different
- * png_store (in fact it never does in this program.)
- */
- struct exception_context
- exception_context;
-
- unsigned int verbose :1;
- unsigned int treat_warnings_as_errors :1;
- unsigned int expect_error :1;
- unsigned int expect_warning :1;
- unsigned int saw_warning :1;
- unsigned int speed :1;
- unsigned int progressive :1; /* use progressive read */
- unsigned int validated :1; /* used as a temporary flag */
- int nerrors;
- int nwarnings;
- char test[128]; /* Name of test */
- char error[256];
-
- /* Read fields */
- png_structp pread; /* Used to read a saved file */
- png_infop piread;
- png_store_file* current; /* Set when reading */
- png_store_buffer* next; /* Set when reading */
- png_size_t readpos; /* Position in *next */
- png_byte* image; /* Buffer for reading interlaced images */
- size_t cb_image; /* Size of this buffer */
- store_pool read_memory_pool;
-
- /* Write fields */
- png_store_file* saved;
- png_structp pwrite; /* Used when writing a new file */
- png_infop piwrite;
- png_size_t writepos; /* Position in .new */
- char wname[FILE_NAME_SIZE];
- png_store_buffer new; /* The end of the new PNG file being written. */
- store_pool write_memory_pool;
-} png_store;
-
-/* Initialization and cleanup */
-static void
-store_pool_mark(png_byte *mark)
-{
- /* Generate a new mark. This uses a boring repeatable algorithm and it is
- * implemented here so that it gives the same set of numbers on every
- * architecture. It's a linear congruential generator (Knuth or Sedgewick
- * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and
- * Hill, "The Art of Electronics".
- */
- static png_uint_32 u0 = 0x12345678, u1 = 1;
-
- /* There are thirty three bits, the next bit in the sequence is bit-33 XOR
- * bit-20. The top 1 bit is in u1, the bottom 32 are in u0.
- */
- int i;
- for (i=0; i<4; ++i)
- {
- /* First generate 8 new bits then shift them in at the end. */
- png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff;
- u1 <<= 8;
- u1 |= u0 >> 24;
- u0 <<= 8;
- u0 |= u;
- *mark++ = (png_byte)u;
- }
-}
-
-/* Use this for random 32 bit values, this function makes sure the result is
- * non-zero.
- */
-static png_uint_32
-random_32(void)
-{
-
- for(;;)
- {
- png_byte mark[4];
- png_uint_32 result;
-
- store_pool_mark(mark);
- result = png_get_uint_32(mark);
-
- if (result != 0)
- return result;
- }
-}
-
-static void
-store_pool_init(png_store *ps, store_pool *pool)
-{
- memset(pool, 0, sizeof *pool);
-
- pool->store = ps;
- pool->list = NULL;
- pool->max = pool->current = pool->limit = pool->total = 0;
- pool->max_max = pool->max_limit = pool->max_total = 0;
- store_pool_mark(pool->mark);
-}
-
-static void
-store_init(png_store* ps)
-{
- memset(ps, 0, sizeof *ps);
- init_exception_context(&ps->exception_context);
- store_pool_init(ps, &ps->read_memory_pool);
- store_pool_init(ps, &ps->write_memory_pool);
- ps->verbose = 0;
- ps->treat_warnings_as_errors = 0;
- ps->expect_error = 0;
- ps->expect_warning = 0;
- ps->saw_warning = 0;
- ps->speed = 0;
- ps->progressive = 0;
- ps->validated = 0;
- ps->nerrors = ps->nwarnings = 0;
- ps->pread = NULL;
- ps->piread = NULL;
- ps->saved = ps->current = NULL;
- ps->next = NULL;
- ps->readpos = 0;
- ps->image = NULL;
- ps->cb_image = 0;
- ps->pwrite = NULL;
- ps->piwrite = NULL;
- ps->writepos = 0;
- ps->new.prev = NULL;
-}
-
-/* This somewhat odd function is used when reading an image to ensure that the
- * buffer is big enough - this is why a png_structp is available.
- */
-static void
-store_ensure_image(png_store *ps, png_structp pp, size_t cb)
-{
- if (ps->cb_image < cb)
- {
- if (ps->image != NULL)
- {
- free(ps->image-1);
- ps->cb_image = 0;
- }
-
- /* The buffer is deliberately mis-aligned. */
- ps->image = malloc(cb+1);
- if (ps->image == NULL)
- png_error(pp, "OOM allocating image buffer");
-
- ++(ps->image);
- ps->cb_image = cb;
- }
-
- /* And, for error checking, the whole buffer is set to '1' - this
- * matches what happens with the 'size' test images on write and also
- * matches the unused bits in the test rows.
- */
- memset(ps->image, 0xff, cb);
-}
-
-static void
-store_freebuffer(png_store_buffer* psb)
-{
- if (psb->prev)
- {
- store_freebuffer(psb->prev);
- free(psb->prev);
- psb->prev = NULL;
- }
-}
-
-static void
-store_freenew(png_store *ps)
-{
- store_freebuffer(&ps->new);
- ps->writepos = 0;
-}
-
-static void
-store_storenew(png_store *ps)
-{
- png_store_buffer *pb;
-
- if (ps->writepos != STORE_BUFFER_SIZE)
- png_error(ps->pwrite, "invalid store call");
-
- pb = malloc(sizeof *pb);
-
- if (pb == NULL)
- png_error(ps->pwrite, "store new: OOM");
-
- *pb = ps->new;
- ps->new.prev = pb;
- ps->writepos = 0;
-}
-
-static void
-store_freefile(png_store_file **ppf)
-{
- if (*ppf != NULL)
- {
- store_freefile(&(*ppf)->next);
-
- store_freebuffer(&(*ppf)->data);
- (*ppf)->datacount = 0;
- free(*ppf);
- *ppf = NULL;
- }
-}
-
-/* Main interface to file storeage, after writing a new PNG file (see the API
- * below) call store_storefile to store the result with the given name and id.
- */
-static void
-store_storefile(png_store *ps, png_uint_32 id)
-{
- png_store_file *pf = malloc(sizeof *pf);
- if (pf == NULL)
- png_error(ps->pwrite, "storefile: OOM");
- safecat(pf->name, sizeof pf->name, 0, ps->wname);
- pf->id = id;
- pf->data = ps->new;
- pf->datacount = ps->writepos;
- ps->new.prev = NULL;
- ps->writepos = 0;
-
- /* And save it. */
- pf->next = ps->saved;
- ps->saved = pf;
-}
-
-/* Generate an error message (in the given buffer) */
-static size_t
-store_message(png_store *ps, png_structp pp, char *buffer, size_t bufsize,
- size_t pos, PNG_CONST char *msg)
-{
- if (pp != NULL && pp == ps->pread)
- {
- /* Reading a file */
- pos = safecat(buffer, bufsize, pos, "read: ");
-
- if (ps->current != NULL)
- {
- pos = safecat(buffer, bufsize, pos, ps->current->name);
- pos = safecat(buffer, bufsize, pos, sep);
- }
- }
-
- else if (pp != NULL && pp == ps->pwrite)
- {
- /* Writing a file */
- pos = safecat(buffer, bufsize, pos, "write: ");
- pos = safecat(buffer, bufsize, pos, ps->wname);
- pos = safecat(buffer, bufsize, pos, sep);
- }
-
- else
- {
- /* Neither reading nor writing (or a memory error in struct delete) */
- pos = safecat(buffer, bufsize, pos, "pngvalid: ");
- }
-
- if (ps->test[0] != 0)
- {
- pos = safecat(buffer, bufsize, pos, ps->test);
- pos = safecat(buffer, bufsize, pos, sep);
- }
- pos = safecat(buffer, bufsize, pos, msg);
- return pos;
-}
-
-/* Log an error or warning - the relevant count is always incremented. */
-static void
-store_log(png_store* ps, png_structp pp, png_const_charp message, int is_error)
-{
- /* The warning is copied to the error buffer if there are no errors and it is
- * the first warning. The error is copied to the error buffer if it is the
- * first error (overwriting any prior warnings).
- */
- if (is_error ? (ps->nerrors)++ == 0 :
- (ps->nwarnings)++ == 0 && ps->nerrors == 0)
- store_message(ps, pp, ps->error, sizeof ps->error, 0, message);
-
- if (ps->verbose)
- {
- char buffer[256];
- size_t pos;
-
- if (is_error)
- pos = safecat(buffer, sizeof buffer, 0, "error: ");
- else
- pos = safecat(buffer, sizeof buffer, 0, "warning: ");
-
- store_message(ps, pp, buffer, sizeof buffer, pos, message);
- fputs(buffer, stderr);
- fputc('\n', stderr);
- }
-}
-
-/* Functions to use as PNG callbacks. */
-static void
-store_error(png_structp pp, png_const_charp message) /* PNG_NORETURN */
-{
- png_store *ps = png_get_error_ptr(pp);
-
- if (!ps->expect_error)
- store_log(ps, pp, message, 1 /* error */);
-
- /* And finally throw an exception. */
- {
- struct exception_context *the_exception_context = &ps->exception_context;
- Throw ps;
- }
-}
-
-static void
-store_warning(png_structp pp, png_const_charp message)
-{
- png_store *ps = png_get_error_ptr(pp);
-
- if (!ps->expect_warning)
- store_log(ps, pp, message, 0 /* warning */);
- else
- ps->saw_warning = 1;
-}
-
-static void
-store_write(png_structp pp, png_bytep pb, png_size_t st)
-{
- png_store *ps = png_get_io_ptr(pp);
-
- if (ps->pwrite != pp)
- png_error(pp, "store state damaged");
-
- while (st > 0)
- {
- size_t cb;
-
- if (ps->writepos >= STORE_BUFFER_SIZE)
- store_storenew(ps);
-
- cb = st;
-
- if (cb > STORE_BUFFER_SIZE - ps->writepos)
- cb = STORE_BUFFER_SIZE - ps->writepos;
-
- memcpy(ps->new.buffer + ps->writepos, pb, cb);
- pb += cb;
- st -= cb;
- ps->writepos += cb;
- }
-}
-
-static void
-store_flush(png_structp pp)
-{
- UNUSED(pp) /*DOES NOTHING*/
-}
-
-static size_t
-store_read_buffer_size(png_store *ps)
-{
- /* Return the bytes available for read in the current buffer. */
- if (ps->next != &ps->current->data)
- return STORE_BUFFER_SIZE;
-
- return ps->current->datacount;
-}
-
-/* Return total bytes available for read. */
-static size_t
-store_read_buffer_avail(png_store *ps)
-{
- if (ps->current != NULL && ps->next != NULL)
- {
- png_store_buffer *next = &ps->current->data;
- size_t cbAvail = ps->current->datacount;
-
- while (next != ps->next && next != NULL)
- {
- next = next->prev;
- cbAvail += STORE_BUFFER_SIZE;
- }
-
- if (next != ps->next)
- png_error(ps->pread, "buffer read error");
-
- if (cbAvail > ps->readpos)
- return cbAvail - ps->readpos;
- }
-
- return 0;
-}
-
-static int
-store_read_buffer_next(png_store *ps)
-{
- png_store_buffer *pbOld = ps->next;
- png_store_buffer *pbNew = &ps->current->data;
- if (pbOld != pbNew)
- {
- while (pbNew != NULL && pbNew->prev != pbOld)
- pbNew = pbNew->prev;
-
- if (pbNew != NULL)
- {
- ps->next = pbNew;
- ps->readpos = 0;
- return 1;
- }
-
- png_error(ps->pread, "buffer lost");
- }
-
- return 0; /* EOF or error */
-}
-
-/* Need separate implementation and callback to allow use of the same code
- * during progressive read, where the io_ptr is set internally by libpng.
- */
-static void
-store_read_imp(png_store *ps, png_bytep pb, png_size_t st)
-{
- if (ps->current == NULL || ps->next == NULL)
- png_error(ps->pread, "store state damaged");
-
- while (st > 0)
- {
- size_t cbAvail = store_read_buffer_size(ps) - ps->readpos;
-
- if (cbAvail > 0)
- {
- if (cbAvail > st) cbAvail = st;
- memcpy(pb, ps->next->buffer + ps->readpos, cbAvail);
- st -= cbAvail;
- pb += cbAvail;
- ps->readpos += cbAvail;
- }
-
- else if (!store_read_buffer_next(ps))
- png_error(ps->pread, "read beyond end of file");
- }
-}
-
-static void
-store_read(png_structp pp, png_bytep pb, png_size_t st)
-{
- png_store *ps = png_get_io_ptr(pp);
-
- if (ps == NULL || ps->pread != pp)
- png_error(pp, "bad store read call");
-
- store_read_imp(ps, pb, st);
-}
-
-static void
-store_progressive_read(png_store *ps, png_structp pp, png_infop pi)
-{
- /* Notice that a call to store_read will cause this function to fail because
- * readpos will be set.
- */
- if (ps->pread != pp || ps->current == NULL || ps->next == NULL)
- png_error(pp, "store state damaged (progressive)");
-
- do
- {
- if (ps->readpos != 0)
- png_error(pp, "store_read called during progressive read");
-
- png_process_data(pp, pi, ps->next->buffer, store_read_buffer_size(ps));
- }
- while (store_read_buffer_next(ps));
-}
-
-/***************************** MEMORY MANAGEMENT*** ***************************/
-/* A store_memory is simply the header for an allocated block of memory. The
- * pointer returned to libpng is just after the end of the header block, the
- * allocated memory is followed by a second copy of the 'mark'.
- */
-typedef struct store_memory
-{
- store_pool *pool; /* Originating pool */
- struct store_memory *next; /* Singly linked list */
- png_alloc_size_t size; /* Size of memory allocated */
- png_byte mark[4]; /* ID marker */
-} store_memory;
-
-/* Handle a fatal error in memory allocation. This calls png_error if the
- * libpng struct is non-NULL, else it outputs a message and returns. This means
- * that a memory problem while libpng is running will abort (png_error) the
- * handling of particular file while one in cleanup (after the destroy of the
- * struct has returned) will simply keep going and free (or attempt to free)
- * all the memory.
- */
-static void
-store_pool_error(png_store *ps, png_structp pp, PNG_CONST char *msg)
-{
- if (pp != NULL)
- png_error(pp, msg);
-
- /* Else we have to do it ourselves. png_error eventually calls store_log,
- * above. store_log accepts a NULL png_structp - it just changes what gets
- * output by store_message.
- */
- store_log(ps, pp, msg, 1 /* error */);
-}
-
-static void
-store_memory_free(png_structp pp, store_pool *pool, store_memory *memory)
-{
- /* Note that pp may be NULL (see store_pool_delete below), the caller has
- * found 'memory' in pool->list *and* unlinked this entry, so this is a valid
- * pointer (for sure), but the contents may have been trashed.
- */
- if (memory->pool != pool)
- store_pool_error(pool->store, pp, "memory corrupted (pool)");
-
- else if (memcmp(memory->mark, pool->mark, sizeof memory->mark) != 0)
- store_pool_error(pool->store, pp, "memory corrupted (start)");
-
- /* It should be safe to read the size field now. */
- else
- {
- png_alloc_size_t cb = memory->size;
-
- if (cb > pool->max)
- store_pool_error(pool->store, pp, "memory corrupted (size)");
-
- else if (memcmp((png_bytep)(memory+1)+cb, pool->mark, sizeof pool->mark)
- != 0)
- store_pool_error(pool->store, pp, "memory corrupted (end)");
-
- /* Finally give the library a chance to find problems too: */
- else
- {
- pool->current -= cb;
- free(memory);
- }
- }
-}
-
-static void
-store_pool_delete(png_store *ps, store_pool *pool)
-{
- if (pool->list != NULL)
- {
- fprintf(stderr, "%s: %s %s: memory lost (list follows):\n", ps->test,
- pool == &ps->read_memory_pool ? "read" : "write",
- pool == &ps->read_memory_pool ? (ps->current != NULL ?
- ps->current->name : "unknown file") : ps->wname);
- ++ps->nerrors;
-
- do
- {
- store_memory *next = pool->list;
- pool->list = next->next;
- next->next = NULL;
-
- fprintf(stderr, "\t%lu bytes @ %p\n",
- (unsigned long)next->size, next+1);
- /* The NULL means this will always return, even if the memory is
- * corrupted.
- */
- store_memory_free(NULL, pool, next);
- }
- while (pool->list != NULL);
- }
-
- /* And reset the other fields too for the next time. */
- if (pool->max > pool->max_max) pool->max_max = pool->max;
- pool->max = 0;
- if (pool->current != 0) /* unexpected internal error */
- fprintf(stderr, "%s: %s %s: memory counter mismatch (internal error)\n",
- ps->test, pool == &ps->read_memory_pool ? "read" : "write",
- pool == &ps->read_memory_pool ? (ps->current != NULL ?
- ps->current->name : "unknown file") : ps->wname);
- pool->current = 0;
-
- if (pool->limit > pool->max_limit)
- pool->max_limit = pool->limit;
-
- pool->limit = 0;
-
- if (pool->total > pool->max_total)
- pool->max_total = pool->total;
-
- pool->total = 0;
-
- /* Get a new mark too. */
- store_pool_mark(pool->mark);
-}
-
-/* The memory callbacks: */
-static png_voidp
-store_malloc(png_structp pp, png_alloc_size_t cb)
-{
- store_pool *pool = png_get_mem_ptr(pp);
- store_memory *new = malloc(cb + (sizeof *new) + (sizeof pool->mark));
-
- if (new != NULL)
- {
- if (cb > pool->max)
- pool->max = cb;
-
- pool->current += cb;
-
- if (pool->current > pool->limit)
- pool->limit = pool->current;
-
- pool->total += cb;
-
- new->size = cb;
- memcpy(new->mark, pool->mark, sizeof new->mark);
- memcpy((png_byte*)(new+1) + cb, pool->mark, sizeof pool->mark);
- new->pool = pool;
- new->next = pool->list;
- pool->list = new;
- ++new;
- }
-
- else
- store_pool_error(pool->store, pp, "out of memory");
-
- return new;
-}
-
-static void
-store_free(png_structp pp, png_voidp memory)
-{
- store_pool *pool = png_get_mem_ptr(pp);
- store_memory *this = memory, **test;
-
- /* First check that this 'memory' really is valid memory - it must be in the
- * pool list. If it is, use the shared memory_free function to free it.
- */
- --this;
- for (test = &pool->list; *test != this; test = &(*test)->next)
- {
- if (*test == NULL)
- {
- store_pool_error(pool->store, pp, "bad pointer to free");
- return;
- }
- }
-
- /* Unlink this entry, *test == this. */
- *test = this->next;
- this->next = NULL;
- store_memory_free(pp, pool, this);
-}
-
-/* Setup functions. */
-/* Cleanup when aborting a write or after storing the new file. */
-static void
-store_write_reset(png_store *ps)
-{
- if (ps->pwrite != NULL)
- {
- anon_context(ps);
-
- Try
- png_destroy_write_struct(&ps->pwrite, &ps->piwrite);
-
- Catch_anonymous
- {
- /* memory corruption: continue. */
- }
-
- ps->pwrite = NULL;
- ps->piwrite = NULL;
- }
-
- /* And make sure that all the memory has been freed - this will output
- * spurious errors in the case of memory corruption above, but this is safe.
- */
- store_pool_delete(ps, &ps->write_memory_pool);
-
- store_freenew(ps);
-}
-
-/* The following is the main write function, it returns a png_struct and,
- * optionally, a png_info suitable for writiing a new PNG file. Use
- * store_storefile above to record this file after it has been written. The
- * returned libpng structures as destroyed by store_write_reset above.
- */
-static png_structp
-set_store_for_write(png_store *ps, png_infopp ppi,
- PNG_CONST char * volatile name)
-{
- anon_context(ps);
-
- Try
- {
- if (ps->pwrite != NULL)
- png_error(ps->pwrite, "write store already in use");
-
- store_write_reset(ps);
- safecat(ps->wname, sizeof ps->wname, 0, name);
-
- /* Don't do the slow memory checks if doing a speed test. */
- if (ps->speed)
- ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING,
- ps, store_error, store_warning);
-
- else
- ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
- ps, store_error, store_warning, &ps->write_memory_pool,
- store_malloc, store_free);
-
- png_set_write_fn(ps->pwrite, ps, store_write, store_flush);
-
- if (ppi != NULL)
- *ppi = ps->piwrite = png_create_info_struct(ps->pwrite);
- }
-
- Catch_anonymous
- return NULL;
-
- return ps->pwrite;
-}
-
-/* Cleanup when finished reading (either due to error or in the success case).
- */
-static void
-store_read_reset(png_store *ps)
-{
- if (ps->pread != NULL)
- {
- anon_context(ps);
-
- Try
- png_destroy_read_struct(&ps->pread, &ps->piread, NULL);
-
- Catch_anonymous
- {
- /* error already output: continue */
- }
-
- ps->pread = NULL;
- ps->piread = NULL;
- }
-
- /* Always do this to be safe. */
- store_pool_delete(ps, &ps->read_memory_pool);
-
- ps->current = NULL;
- ps->next = NULL;
- ps->readpos = 0;
- ps->validated = 0;
-}
-
-static void
-store_read_set(png_store *ps, png_uint_32 id)
-{
- png_store_file *pf = ps->saved;
-
- while (pf != NULL)
- {
- if (pf->id == id)
- {
- ps->current = pf;
- ps->next = NULL;
- store_read_buffer_next(ps);
- return;
- }
-
- pf = pf->next;
- }
-
- {
- size_t pos;
- char msg[FILE_NAME_SIZE+64];
-
- pos = standard_name_from_id(msg, sizeof msg, 0, id);
- pos = safecat(msg, sizeof msg, pos, ": file not found");
- png_error(ps->pread, msg);
- }
-}
-
-/* The main interface for reading a saved file - pass the id number of the file
- * to retrieve. Ids must be unique or the earlier file will be hidden. The API
- * returns a png_struct and, optionally, a png_info. Both of these will be
- * destroyed by store_read_reset above.
- */
-static png_structp
-set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id,
- PNG_CONST char *name)
-{
- /* Set the name for png_error */
- safecat(ps->test, sizeof ps->test, 0, name);
-
- if (ps->pread != NULL)
- png_error(ps->pread, "read store already in use");
-
- store_read_reset(ps);
-
- /* Both the create APIs can return NULL if used in their default mode
- * (because there is no other way of handling an error because the jmp_buf
- * by default is stored in png_struct and that has not been allocated!)
- * However, given that store_error works correctly in these circumstances
- * we don't ever expect NULL in this program.
- */
- if (ps->speed)
- ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps,
- store_error, store_warning);
-
- else
- ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps,
- store_error, store_warning, &ps->read_memory_pool, store_malloc,
- store_free);
-
- if (ps->pread == NULL)
- {
- struct exception_context *the_exception_context = &ps->exception_context;
-
- store_log(ps, NULL, "png_create_read_struct returned NULL (unexpected)",
- 1 /*error*/);
-
- Throw ps;
- }
-
- store_read_set(ps, id);
-
- if (ppi != NULL)
- *ppi = ps->piread = png_create_info_struct(ps->pread);
-
- return ps->pread;
-}
-
-/* The overall cleanup of a store simply calls the above then removes all the
- * saved files. This does not delete the store itself.
- */
-static void
-store_delete(png_store *ps)
-{
- store_write_reset(ps);
- store_read_reset(ps);
- store_freefile(&ps->saved);
-
- if (ps->image != NULL)
- {
- free(ps->image-1);
- ps->image = NULL;
- ps->cb_image = 0;
- }
-}
-
-/*********************** PNG FILE MODIFICATION ON READ ************************/
-/* Files may be modified on read. The following structure contains a complete
- * png_store together with extra members to handle modification and a special
- * read callback for libpng. To use this the 'modifications' field must be set
- * to a list of png_modification structures that actually perform the
- * modification, otherwise a png_modifier is functionally equivalent to a
- * png_store. There is a special read function, set_modifier_for_read, which
- * replaces set_store_for_read.
- */
-typedef struct png_modifier
-{
- png_store this; /* I am a png_store */
- struct png_modification *modifications; /* Changes to make */
-
- enum modifier_state
- {
- modifier_start, /* Initial value */
- modifier_signature, /* Have a signature */
- modifier_IHDR /* Have an IHDR */
- } state; /* My state */
-
- /* Information from IHDR: */
- png_byte bit_depth; /* From IHDR */
- png_byte colour_type; /* From IHDR */
-
- /* While handling PLTE, IDAT and IEND these chunks may be pended to allow
- * other chunks to be inserted.
- */
- png_uint_32 pending_len;
- png_uint_32 pending_chunk;
-
- /* Test values */
- double *gammas;
- unsigned int ngammas;
-
- /* Lowest sbit to test (libpng fails for sbit < 8) */
- png_byte sbitlow;
-
- /* Error control - these are the limits on errors accepted by the gamma tests
- * below.
- */
- double maxout8; /* Maximum output value error */
- double maxabs8; /* Absolute sample error 0..1 */
- double maxpc8; /* Percentage sample error 0..100% */
- double maxout16; /* Maximum output value error */
- double maxabs16; /* Absolute sample error 0..1 */
- double maxpc16; /* Percentage sample error 0..100% */
-
- /* Logged 8 and 16 bit errors ('output' values): */
- double error_gray_2;
- double error_gray_4;
- double error_gray_8;
- double error_gray_16;
- double error_color_8;
- double error_color_16;
-
- /* Flags: */
- /* Whether or not to interlace. */
- int interlace_type :9; /* int, but must store '1' */
-
- /* Run the standard tests? */
- unsigned int test_standard :1;
-
- /* Run the odd-sized image and interlace read/write tests? */
- unsigned int test_size :1;
-
- /* Run tests on reading with a combiniation of transforms, */
- unsigned int test_transform :1;
-
- /* When to use the use_input_precision option: */
- unsigned int use_input_precision :1;
- unsigned int use_input_precision_sbit :1;
- unsigned int use_input_precision_16to8 :1;
-
- /* Which gamma tests to run: */
- unsigned int test_gamma_threshold :1;
- unsigned int test_gamma_transform :1; /* main tests */
- unsigned int test_gamma_sbit :1;
- unsigned int test_gamma_strip16 :1;
-
- unsigned int log :1; /* Log max error */
-
- /* Buffer information, the buffer size limits the size of the chunks that can
- * be modified - they must fit (including header and CRC) into the buffer!
- */
- size_t flush; /* Count of bytes to flush */
- size_t buffer_count; /* Bytes in buffer */
- size_t buffer_position; /* Position in buffer */
- png_byte buffer[1024];
-} png_modifier;
-
-static double abserr(png_modifier *pm, png_byte bit_depth)
-{
- return bit_depth == 16 ? pm->maxabs16 : pm->maxabs8;
-}
-
-static double pcerr(png_modifier *pm, png_byte bit_depth)
-{
- return (bit_depth == 16 ? pm->maxpc16 : pm->maxpc8) * .01;
-}
-
-static double outerr(png_modifier *pm, png_byte bit_depth)
-{
- /* There is a serious error in the 2 and 4 bit grayscale transform because
- * the gamma table value (8 bits) is simply shifted, not rounded, so the
- * error in 4 bit greyscale gamma is up to the value below. This is a hack
- * to allow pngvalid to succeed:
- */
- if (bit_depth == 2)
- return .73182-.5;
-
- if (bit_depth == 4)
- return .90644-.5;
-
- if (bit_depth == 16)
- return pm->maxout16;
-
- return pm->maxout8;
-}
-
-/* This returns true if the test should be stopped now because it has already
- * failed and it is running silently.
- */
-static int fail(png_modifier *pm)
-{
- return !pm->log && !pm->this.verbose && (pm->this.nerrors > 0 ||
- (pm->this.treat_warnings_as_errors && pm->this.nwarnings > 0));
-}
-
-static void
-modifier_init(png_modifier *pm)
-{
- memset(pm, 0, sizeof *pm);
- store_init(&pm->this);
- pm->modifications = NULL;
- pm->state = modifier_start;
- pm->sbitlow = 1U;
- pm->maxout8 = pm->maxpc8 = pm->maxabs8 = 0;
- pm->maxout16 = pm->maxpc16 = pm->maxabs16 = 0;
- pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0;
- pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0;
- pm->interlace_type = PNG_INTERLACE_NONE;
- pm->test_standard = 0;
- pm->test_size = 0;
- pm->test_transform = 0;
- pm->use_input_precision = 0;
- pm->use_input_precision_sbit = 0;
- pm->use_input_precision_16to8 = 0;
- pm->test_gamma_threshold = 0;
- pm->test_gamma_transform = 0;
- pm->test_gamma_sbit = 0;
- pm->test_gamma_strip16 = 0;
- pm->log = 0;
-
- /* Rely on the memset for all the other fields - there are no pointers */
-}
-
-/* One modification structure must be provided for each chunk to be modified (in
- * fact more than one can be provided if multiple separate changes are desired
- * for a single chunk.) Modifications include adding a new chunk when a
- * suitable chunk does not exist.
- *
- * The caller of modify_fn will reset the CRC of the chunk and record 'modified'
- * or 'added' as appropriate if the modify_fn returns 1 (true). If the
- * modify_fn is NULL the chunk is simply removed.
- */
-typedef struct png_modification
-{
- struct png_modification *next;
- png_uint_32 chunk;
-
- /* If the following is NULL all matching chunks will be removed: */
- int (*modify_fn)(struct png_modifier *pm,
- struct png_modification *me, int add);
-
- /* If the following is set to PLTE, IDAT or IEND and the chunk has not been
- * found and modified (and there is a modify_fn) the modify_fn will be called
- * to add the chunk before the relevant chunk.
- */
- png_uint_32 add;
- unsigned int modified :1; /* Chunk was modified */
- unsigned int added :1; /* Chunk was added */
- unsigned int removed :1; /* Chunk was removed */
-} png_modification;
-
-static void modification_reset(png_modification *pmm)
-{
- if (pmm != NULL)
- {
- pmm->modified = 0;
- pmm->added = 0;
- pmm->removed = 0;
- modification_reset(pmm->next);
- }
-}
-
-static void
-modification_init(png_modification *pmm)
-{
- memset(pmm, 0, sizeof *pmm);
- pmm->next = NULL;
- pmm->chunk = 0;
- pmm->modify_fn = NULL;
- pmm->add = 0;
- modification_reset(pmm);
-}
-
-static void
-modifier_reset(png_modifier *pm)
-{
- store_read_reset(&pm->this);
- pm->modifications = NULL;
- pm->state = modifier_start;
- pm->bit_depth = pm->colour_type = 0;
- pm->pending_len = pm->pending_chunk = 0;
- pm->flush = pm->buffer_count = pm->buffer_position = 0;
-}
-
-/* Convenience macros. */
-#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d))
-#define CHUNK_IHDR CHUNK(73,72,68,82)
-#define CHUNK_PLTE CHUNK(80,76,84,69)
-#define CHUNK_IDAT CHUNK(73,68,65,84)
-#define CHUNK_IEND CHUNK(73,69,78,68)
-#define CHUNK_cHRM CHUNK(99,72,82,77)
-#define CHUNK_gAMA CHUNK(103,65,77,65)
-#define CHUNK_sBIT CHUNK(115,66,73,84)
-#define CHUNK_sRGB CHUNK(115,82,71,66)
-
-/* The guts of modification are performed during a read. */
-static void
-modifier_crc(png_bytep buffer)
-{
- /* Recalculate the chunk CRC - a complete chunk must be in
- * the buffer, at the start.
- */
- uInt datalen = png_get_uint_32(buffer);
- png_save_uint_32(buffer+datalen+8, crc32(0L, buffer+4, datalen+4));
-}
-
-static void
-modifier_setbuffer(png_modifier *pm)
-{
- modifier_crc(pm->buffer);
- pm->buffer_count = png_get_uint_32(pm->buffer)+12;
- pm->buffer_position = 0;
-}
-
-/* Separate the callback into the actual implementation (which is passed the
- * png_modifier explicitly) and the callback, which gets the modifier from the
- * png_struct.
- */
-static void
-modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
-{
- while (st > 0)
- {
- size_t cb;
- png_uint_32 len, chunk;
- png_modification *mod;
-
- if (pm->buffer_position >= pm->buffer_count) switch (pm->state)
- {
- static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 };
- case modifier_start:
- store_read_imp(&pm->this, pm->buffer, 8); /* size of signature. */
- pm->buffer_count = 8;
- pm->buffer_position = 0;
-
- if (memcmp(pm->buffer, sign, 8) != 0)
- png_error(pm->this.pread, "invalid PNG file signature");
- pm->state = modifier_signature;
- break;
-
- case modifier_signature:
- store_read_imp(&pm->this, pm->buffer, 13+12); /* size of IHDR */
- pm->buffer_count = 13+12;
- pm->buffer_position = 0;
-
- if (png_get_uint_32(pm->buffer) != 13 ||
- png_get_uint_32(pm->buffer+4) != CHUNK_IHDR)
- png_error(pm->this.pread, "invalid IHDR");
-
- /* Check the list of modifiers for modifications to the IHDR. */
- mod = pm->modifications;
- while (mod != NULL)
- {
- if (mod->chunk == CHUNK_IHDR && mod->modify_fn &&
- (*mod->modify_fn)(pm, mod, 0))
- {
- mod->modified = 1;
- modifier_setbuffer(pm);
- }
-
- /* Ignore removal or add if IHDR! */
- mod = mod->next;
- }
-
- /* Cache information from the IHDR (the modified one.) */
- pm->bit_depth = pm->buffer[8+8];
- pm->colour_type = pm->buffer[8+8+1];
-
- pm->state = modifier_IHDR;
- pm->flush = 0;
- break;
-
- case modifier_IHDR:
- default:
- /* Read a new chunk and process it until we see PLTE, IDAT or
- * IEND. 'flush' indicates that there is still some data to
- * output from the preceding chunk.
- */
- if ((cb = pm->flush) > 0)
- {
- if (cb > st) cb = st;
- pm->flush -= cb;
- store_read_imp(&pm->this, pb, cb);
- pb += cb;
- st -= cb;
- if (st <= 0) return;
- }
-
- /* No more bytes to flush, read a header, or handle a pending
- * chunk.
- */
- if (pm->pending_chunk != 0)
- {
- png_save_uint_32(pm->buffer, pm->pending_len);
- png_save_uint_32(pm->buffer+4, pm->pending_chunk);
- pm->pending_len = 0;
- pm->pending_chunk = 0;
- }
- else
- store_read_imp(&pm->this, pm->buffer, 8);
-
- pm->buffer_count = 8;
- pm->buffer_position = 0;
-
- /* Check for something to modify or a terminator chunk. */
- len = png_get_uint_32(pm->buffer);
- chunk = png_get_uint_32(pm->buffer+4);
-
- /* Terminators first, they may have to be delayed for added
- * chunks
- */
- if (chunk == CHUNK_PLTE || chunk == CHUNK_IDAT ||
- chunk == CHUNK_IEND)
- {
- mod = pm->modifications;
-
- while (mod != NULL)
- {
- if ((mod->add == chunk ||
- (mod->add == CHUNK_PLTE && chunk == CHUNK_IDAT)) &&
- mod->modify_fn != NULL && !mod->modified && !mod->added)
- {
- /* Regardless of what the modify function does do not run
- * this again.
- */
- mod->added = 1;
-
- if ((*mod->modify_fn)(pm, mod, 1 /*add*/))
- {
- /* Reset the CRC on a new chunk */
- if (pm->buffer_count > 0)
- modifier_setbuffer(pm);
-
- else
- {
- pm->buffer_position = 0;
- mod->removed = 1;
- }
-
- /* The buffer has been filled with something (we assume)
- * so output this. Pend the current chunk.
- */
- pm->pending_len = len;
- pm->pending_chunk = chunk;
- break; /* out of while */
- }
- }
-
- mod = mod->next;
- }
-
- /* Don't do any further processing if the buffer was modified -
- * otherwise the code will end up modifying a chunk that was
- * just added.
- */
- if (mod != NULL)
- break; /* out of switch */
- }
-
- /* If we get to here then this chunk may need to be modified. To
- * do this it must be less than 1024 bytes in total size, otherwise
- * it just gets flushed.
- */
- if (len+12 <= sizeof pm->buffer)
- {
- store_read_imp(&pm->this, pm->buffer+pm->buffer_count,
- len+12-pm->buffer_count);
- pm->buffer_count = len+12;
-
- /* Check for a modification, else leave it be. */
- mod = pm->modifications;
- while (mod != NULL)
- {
- if (mod->chunk == chunk)
- {
- if (mod->modify_fn == NULL)
- {
- /* Remove this chunk */
- pm->buffer_count = pm->buffer_position = 0;
- mod->removed = 1;
- break; /* Terminate the while loop */
- }
-
- else if ((*mod->modify_fn)(pm, mod, 0))
- {
- mod->modified = 1;
- /* The chunk may have been removed: */
- if (pm->buffer_count == 0)
- {
- pm->buffer_position = 0;
- break;
- }
- modifier_setbuffer(pm);
- }
- }
-
- mod = mod->next;
- }
- }
-
- else
- pm->flush = len+12 - pm->buffer_count; /* data + crc */
-
- /* Take the data from the buffer (if there is any). */
- break;
- }
-
- /* Here to read from the modifier buffer (not directly from
- * the store, as in the flush case above.)
- */
- cb = pm->buffer_count - pm->buffer_position;
-
- if (cb > st)
- cb = st;
-
- memcpy(pb, pm->buffer + pm->buffer_position, cb);
- st -= cb;
- pb += cb;
- pm->buffer_position += cb;
- }
-}
-
-/* The callback: */
-static void
-modifier_read(png_structp pp, png_bytep pb, png_size_t st)
-{
- png_modifier *pm = png_get_io_ptr(pp);
-
- if (pm == NULL || pm->this.pread != pp)
- png_error(pp, "bad modifier_read call");
-
- modifier_read_imp(pm, pb, st);
-}
-
-/* Like store_progressive_read but the data is getting changed as we go so we
- * need a local buffer.
- */
-static void
-modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi)
-{
- if (pm->this.pread != pp || pm->this.current == NULL ||
- pm->this.next == NULL)
- png_error(pp, "store state damaged (progressive)");
-
- /* This is another Horowitz and Hill random noise generator. In this case
- * the aim is to stress the progressive reader with truely horrible variable
- * buffer sizes in the range 1..500, so a sequence of 9 bit random numbers
- * is generated. We could probably just count from 1 to 32767 and get as
- * good a result.
- */
- for (;;)
- {
- static png_uint_32 noise = 1;
- png_size_t cb, cbAvail;
- png_byte buffer[512];
-
- /* Generate 15 more bits of stuff: */
- noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff);
- cb = noise & 0x1ff;
-
- /* Check that this number of bytes are available (in the current buffer.)
- * (This doesn't quite work - the modifier might delete a chunk; unlikely
- * but possible, it doesn't happen at present because the modifier only
- * adds chunks to standard images.)
- */
- cbAvail = store_read_buffer_avail(&pm->this);
- if (pm->buffer_count > pm->buffer_position)
- cbAvail += pm->buffer_count - pm->buffer_position;
-
- if (cb > cbAvail)
- {
- /* Check for EOF: */
- if (cbAvail == 0)
- break;
-
- cb = cbAvail;
- }
-
- modifier_read_imp(pm, buffer, cb);
- png_process_data(pp, pi, buffer, cb);
- }
-
- /* Check the invariants at the end (if this fails it's a problem in this
- * file!)
- */
- if (pm->buffer_count > pm->buffer_position ||
- pm->this.next != &pm->this.current->data ||
- pm->this.readpos < pm->this.current->datacount)
- png_error(pp, "progressive read implementation error");
-}
-
-/* Set up a modifier. */
-static png_structp
-set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id,
- PNG_CONST char *name)
-{
- /* Do this first so that the modifier fields are cleared even if an error
- * happens allocating the png_struct. No allocation is done here so no
- * cleanup is required.
- */
- pm->state = modifier_start;
- pm->bit_depth = 0;
- pm->colour_type = 255;
-
- pm->pending_len = 0;
- pm->pending_chunk = 0;
- pm->flush = 0;
- pm->buffer_count = 0;
- pm->buffer_position = 0;
-
- return set_store_for_read(&pm->this, ppi, id, name);
-}
-
-/***************************** STANDARD PNG FILES *****************************/
-/* Standard files - write and save standard files. */
-/* There are two basic forms of standard images. Those which attempt to have
- * all the possible pixel values (not possible for 16bpp images, but a range of
- * values are produced) and those which have a range of image sizes. The former
- * are used for testing transforms, in particular gamma correction and bit
- * reduction and increase. The latter are reserved for testing the behavior of
- * libpng with respect to 'odd' image sizes - particularly small images where
- * rows become 1 byte and interlace passes disappear.
- *
- * The first, most useful, set are the 'transform' images, the second set of
- * small images are the 'size' images.
- *
- * The transform files are constructed with rows which fit into a 1024 byte row
- * buffer. This makes allocation easier below. Further regardless of the file
- * format every row has 128 pixels (giving 1024 bytes for 64bpp formats).
- *
- * Files are stored with no gAMA or sBIT chunks, with a PLTE only when needed
- * and with an ID derived from the colour type, bit depth and interlace type
- * as above (FILEID). The width (128) and height (variable) are not stored in
- * the FILEID - instead the fields are set to 0, indicating a transform file.
- *
- * The size files ar constructed with rows a maximum of 128 bytes wide, allowing
- * a maximum width of 16 pixels (for the 64bpp case.) They also have a maximum
- * height of 16 rows. The width and height are stored in the FILEID and, being
- * non-zero, indicate a size file.
- */
-
-/* The number of passes is related to the interlace type. There wass no libpng
- * API to determine this prior to 1.5, so we need an inquiry function:
- */
-static int
-npasses_from_interlace_type(png_structp pp, int interlace_type)
-{
- switch (interlace_type)
- {
- default:
- png_error(pp, "invalid interlace type");
-
- case PNG_INTERLACE_NONE:
- return 1;
-
- case PNG_INTERLACE_ADAM7:
- return PNG_INTERLACE_ADAM7_PASSES;
- }
-}
-
-static unsigned int
-bit_size(png_structp pp, png_byte colour_type, png_byte bit_depth)
-{
- switch (colour_type)
- {
- case 0: return bit_depth;
-
- case 2: return 3*bit_depth;
-
- case 3: return bit_depth;
-
- case 4: return 2*bit_depth;
-
- case 6: return 4*bit_depth;
-
- default: png_error(pp, "invalid color type");
- }
-}
-
-#define TRANSFORM_WIDTH 128U
-#define TRANSFORM_ROWMAX (TRANSFORM_WIDTH*8U)
-#define SIZE_ROWMAX (16*8U) /* 16 pixels, max 8 bytes each - 128 bytes */
-#define STANDARD_ROWMAX TRANSFORM_ROWMAX /* The larger of the two */
-
-/* So the maximum image sizes are as follows. A 'transform' image may require
- * more than 65535 bytes. The size images are a maximum of 2046 bytes.
- */
-#define TRANSFORM_IMAGEMAX (TRANSFORM_ROWMAX * (png_uint_32)2048)
-#define SIZE_IMAGEMAX (SIZE_ROWMAX * 16U)
-
-static size_t
-transform_rowsize(png_structp pp, png_byte colour_type, png_byte bit_depth)
-{
- return (TRANSFORM_WIDTH * bit_size(pp, colour_type, bit_depth)) / 8;
-}
-
-/* transform_width(pp, colour_type, bit_depth) current returns the same number
- * every time, so just use a macro:
- */
-#define transform_width(pp, colour_type, bit_depth) TRANSFORM_WIDTH
-
-static png_uint_32
-transform_height(png_structp pp, png_byte colour_type, png_byte bit_depth)
-{
- switch (bit_size(pp, colour_type, bit_depth))
- {
- case 1:
- case 2:
- case 4:
- return 1; /* Total of 128 pixels */
-
- case 8:
- return 2; /* Total of 256 pixels/bytes */
-
- case 16:
- return 512; /* Total of 65536 pixels */
-
- case 24:
- case 32:
- return 512; /* 65536 pixels */
-
- case 48:
- case 64:
- return 2048;/* 4 x 65536 pixels. */
-
- default:
- return 0; /* Error, will be caught later */
- }
-}
-
-/* The following can only be defined here, now we have the definitions
- * of the transform image sizes.
- */
-static png_uint_32
-standard_width(png_structp pp, png_uint_32 id)
-{
- png_uint_32 width = WIDTH_FROM_ID(id);
- UNUSED(pp)
-
- if (width == 0)
- width = transform_width(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id));
-
- return width;
-}
-
-static png_uint_32
-standard_height(png_structp pp, png_uint_32 id)
-{
- png_uint_32 height = HEIGHT_FROM_ID(id);
-
- if (height == 0)
- height = transform_height(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id));
-
- return height;
-}
-
-static png_uint_32
-standard_rowsize(png_structp pp, png_uint_32 id)
-{
- png_uint_32 width = standard_width(pp, id);
-
- /* This won't overflow: */
- width *= bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id));
- return (width + 7) / 8;
-}
-
-static void
-transform_row(png_structp pp, png_byte buffer[TRANSFORM_ROWMAX],
- png_byte colour_type, png_byte bit_depth, png_uint_32 y)
-{
- png_uint_32 v = y << 7;
- png_uint_32 i = 0;
-
- switch (bit_size(pp, colour_type, bit_depth))
- {
- case 1:
- while (i<128/8) buffer[i] = v & 0xff, v += 17, ++i;
- return;
-
- case 2:
- while (i<128/4) buffer[i] = v & 0xff, v += 33, ++i;
- return;
-
- case 4:
- while (i<128/2) buffer[i] = v & 0xff, v += 65, ++i;
- return;
-
- case 8:
- /* 256 bytes total, 128 bytes in each row set as follows: */
- while (i<128) buffer[i] = v & 0xff, ++v, ++i;
- return;
-
- case 16:
- /* Generate all 65536 pixel values in order, which includes the 8 bit
- * GA case as well as the 16 bit G case.
- */
- while (i<128)
- buffer[2*i] = (v>>8) & 0xff, buffer[2*i+1] = v & 0xff, ++v, ++i;
-
- return;
-
- case 24:
- /* 65535 pixels, but rotate the values. */
- while (i<128)
- {
- /* Three bytes per pixel, r, g, b, make b by r^g */
- buffer[3*i+0] = (v >> 8) & 0xff;
- buffer[3*i+1] = v & 0xff;
- buffer[3*i+2] = ((v >> 8) ^ v) & 0xff;
- ++v;
- ++i;
- }
-
- return;
-
- case 32:
- /* 65535 pixels, r, g, b, a; just replicate */
- while (i<128)
- {
- buffer[4*i+0] = (v >> 8) & 0xff;
- buffer[4*i+1] = v & 0xff;
- buffer[4*i+2] = (v >> 8) & 0xff;
- buffer[4*i+3] = v & 0xff;
- ++v;
- ++i;
- }
-
- return;
-
- case 48:
- /* y is maximum 2047, giving 4x65536 pixels, make 'r' increase by 1 at
- * each pixel, g increase by 257 (0x101) and 'b' by 0x1111:
- */
- while (i<128)
- {
- png_uint_32 t = v++;
- buffer[6*i+0] = (t >> 8) & 0xff;
- buffer[6*i+1] = t & 0xff;
- t *= 257;
- buffer[6*i+2] = (t >> 8) & 0xff;
- buffer[6*i+3] = t & 0xff;
- t *= 17;
- buffer[6*i+4] = (t >> 8) & 0xff;
- buffer[6*i+5] = t & 0xff;
- ++i;
- }
-
- return;
-
- case 64:
- /* As above in the 32 bit case. */
- while (i<128)
- {
- png_uint_32 t = v++;
- buffer[8*i+0] = (t >> 8) & 0xff;
- buffer[8*i+1] = t & 0xff;
- buffer[8*i+4] = (t >> 8) & 0xff;
- buffer[8*i+5] = t & 0xff;
- t *= 257;
- buffer[8*i+2] = (t >> 8) & 0xff;
- buffer[8*i+3] = t & 0xff;
- buffer[8*i+6] = (t >> 8) & 0xff;
- buffer[8*i+7] = t & 0xff;
- ++i;
- }
- return;
-
- default:
- break;
- }
-
- png_error(pp, "internal error");
-}
-
-/* This is just to do the right cast - could be changed to a function to check
- * 'bd' but there isn't much point.
- */
-#define DEPTH(bd) ((png_byte)(1U << (bd)))
-
-/* Make a standardized image given a an image colour type, bit depth and
- * interlace type. The standard images have a very restricted range of
- * rows and heights and are used for testing transforms rather than image
- * layout details. See make_size_images below for a way to make images
- * that test odd sizes along with the libpng interlace handling.
- */
-static void
-make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
- png_byte PNG_CONST bit_depth, int interlace_type, png_const_charp name)
-{
- context(ps, fault);
-
- Try
- {
- png_infop pi;
- png_structp pp = set_store_for_write(ps, &pi, name);
- png_uint_32 h;
-
- /* In the event of a problem return control to the Catch statement below
- * to do the clean up - it is not possible to 'return' directly from a Try
- * block.
- */
- if (pp == NULL)
- Throw ps;
-
- h = transform_height(pp, colour_type, bit_depth);
-
- png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), h,
- bit_depth, colour_type, interlace_type,
- PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
-
- if (colour_type == 3) /* palette */
- {
- unsigned int i = 0;
- png_color pal[256];
-
- do
- pal[i].red = pal[i].green = pal[i].blue = (png_byte)i;
- while(++i < 256U);
-
- png_set_PLTE(pp, pi, pal, 256);
- }
-
- png_write_info(pp, pi);
-
- if (png_get_rowbytes(pp, pi) !=
- transform_rowsize(pp, colour_type, bit_depth))
- png_error(pp, "row size incorrect");
-
- else
- {
- /* Somewhat confusingly this must be called *after* png_write_info
- * because if it is called before, the information in *pp has not been
- * updated to reflect the interlaced image.
- */
- int npasses = png_set_interlace_handling(pp);
- int pass;
-
- if (npasses != npasses_from_interlace_type(pp, interlace_type))
- png_error(pp, "write: png_set_interlace_handling failed");
-
- for (pass=0; pass<npasses; ++pass)
- {
- png_uint_32 y;
-
- for (y=0; y<h; ++y)
- {
- png_byte buffer[TRANSFORM_ROWMAX];
-
- transform_row(pp, buffer, colour_type, bit_depth, y);
- png_write_row(pp, buffer);
- }
- }
- }
-
- png_write_end(pp, pi);
-
- /* And store this under the appropriate id, then clean up. */
- store_storefile(ps, FILEID(colour_type, bit_depth, interlace_type,
- 0, 0, 0));
-
- store_write_reset(ps);
- }
-
- Catch(fault)
- {
- /* Use the png_store returned by the exception. This may help the compiler
- * because 'ps' is not used in this branch of the setjmp. Note that fault
- * and ps will always be the same value.
- */
- store_write_reset(fault);
- }
-}
-
-static void
-make_standard(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo,
- int PNG_CONST bdhi)
-{
- for (; bdlo <= bdhi; ++bdlo)
- {
- int interlace_type;
-
- for (interlace_type = PNG_INTERLACE_NONE;
- interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
- {
- char name[FILE_NAME_SIZE];
-
- standard_name(name, sizeof name, 0, colour_type, bdlo, interlace_type,
- 0, 0, 0);
- make_transform_image(ps, colour_type, DEPTH(bdlo), interlace_type,
- name);
- }
- }
-}
-
-static void
-make_transform_images(png_store *ps)
-{
- /* This is in case of errors. */
- safecat(ps->test, sizeof ps->test, 0, "make standard images");
-
- /* Arguments are colour_type, low bit depth, high bit depth
- */
- make_standard(ps, 0, 0, WRITE_BDHI);
- make_standard(ps, 2, 3, WRITE_BDHI);
- make_standard(ps, 3, 0, 3 /*palette: max 8 bits*/);
- make_standard(ps, 4, 3, WRITE_BDHI);
- make_standard(ps, 6, 3, WRITE_BDHI);
-}
-
-/* The following two routines use the PNG interlace support macros from
- * png.h to interlace or deinterlace rows.
- */
-static void
-interlace_row(png_bytep buffer, png_const_bytep imageRow,
- unsigned int pixel_size, png_uint_32 w, int pass)
-{
- png_uint_32 xin, xout, xstep;
-
- /* Note that this can, trivially, be optimized to a memcpy on pass 7, the
- * code is presented this way to make it easier to understand. In practice
- * consult the code in the libpng source to see other ways of doing this.
- */
- xin = PNG_PASS_START_COL(pass);
- xstep = 1U<<PNG_PASS_COL_SHIFT(pass);
-
- for (xout=0; xin<w; xin+=xstep)
- {
- pixel_copy(buffer, xout, imageRow, xin, pixel_size);
- ++xout;
- }
-}
-
-static void
-deinterlace_row(png_bytep buffer, png_const_bytep row,
- unsigned int pixel_size, png_uint_32 w, int pass)
-{
- /* The inverse of the above, 'row' is part of row 'y' of the output image,
- * in 'buffer'. The image is 'w' wide and this is pass 'pass', distribute
- * the pixels of row into buffer and return the number written (to allow
- * this to be checked).
- */
- png_uint_32 xin, xout, xstep;
-
- xout = PNG_PASS_START_COL(pass);
- xstep = 1U<<PNG_PASS_COL_SHIFT(pass);
-
- for (xin=0; xout<w; xout+=xstep)
- {
- pixel_copy(buffer, xout, row, xin, pixel_size);
- ++xin;
- }
-}
-
-/* Build a single row for the 'size' test images, this fills in only the
- * first bit_width bits of the sample row.
- */
-static void
-size_row(png_byte buffer[SIZE_ROWMAX], png_uint_32 bit_width, png_uint_32 y)
-{
- /* height is in the range 1 to 16, so: */
- y = ((y & 1) << 7) + ((y & 2) << 6) + ((y & 4) << 5) + ((y & 8) << 4);
- /* the following ensures bits are set in small images: */
- y ^= 0xA5;
-
- while (bit_width >= 8)
- *buffer++ = (png_byte)y++, bit_width -= 8;
-
- /* There may be up to 7 remaining bits, these go in the most significant
- * bits of the byte.
- */
- if (bit_width > 0)
- {
- png_uint_32 mask = (1U<<(8-bit_width))-1;
- *buffer = (png_byte)((*buffer & mask) | (y & ~mask));
- }
-}
-
-static void
-make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
- png_byte PNG_CONST bit_depth, int PNG_CONST interlace_type,
- png_uint_32 PNG_CONST w, png_uint_32 PNG_CONST h,
- int PNG_CONST do_interlace)
-{
- context(ps, fault);
-
- Try
- {
- png_infop pi;
- png_structp pp;
- unsigned int pixel_size;
-
- /* Make a name and get an appropriate id for the store: */
- char name[FILE_NAME_SIZE];
- PNG_CONST png_uint_32 id = FILEID(colour_type, bit_depth, interlace_type,
- w, h, do_interlace);
-
- standard_name_from_id(name, sizeof name, 0, id);
- pp = set_store_for_write(ps, &pi, name);
-
- /* In the event of a problem return control to the Catch statement below
- * to do the clean up - it is not possible to 'return' directly from a Try
- * block.
- */
- if (pp == NULL)
- Throw ps;
-
- png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type,
- PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
-
- /* Same palette as make_transform_image - I don' think there is any
- * benefit from using a different one (JB 20101211)
- */
- if (colour_type == 3) /* palette */
- {
- unsigned int i = 0;
- png_color pal[256];
-
- do
- pal[i].red = pal[i].green = pal[i].blue = (png_byte)i;
- while(++i < 256U);
-
- png_set_PLTE(pp, pi, pal, 256);
- }
-
- png_write_info(pp, pi);
-
- /* Calculate the bit size, divide by 8 to get the byte size - this won't
- * overflow because we know the w values are all small enough even for
- * a system where 'unsigned int' is only 16 bits.
- */
- pixel_size = bit_size(pp, colour_type, bit_depth);
- if (png_get_rowbytes(pp, pi) != ((w * pixel_size) + 7) / 8)
- png_error(pp, "row size incorrect");
-
- else
- {
- int npasses = npasses_from_interlace_type(pp, interlace_type);
- png_uint_32 y;
- int pass;
- png_byte image[16][SIZE_ROWMAX];
-
- /* To help consistent error detection make the parts of this buffer
- * that aren't set below all '1':
- */
- memset(image, 0xff, sizeof image);
-
- if (!do_interlace && npasses != png_set_interlace_handling(pp))
- png_error(pp, "write: png_set_interlace_handling failed");
-
- /* Prepare the whole image first to avoid making it 7 times: */
- for (y=0; y<h; ++y)
- size_row(image[y], w * pixel_size, y);
-
- for (pass=0; pass<npasses; ++pass)
- {
- /* The following two are for checking the macros: */
- PNG_CONST png_uint_32 wPass = PNG_PASS_COLS(w, pass);
-
- /* If do_interlace is set we don't call png_write_row for every
- * row because some of them are empty. In fact, for a 1x1 image,
- * most of them are empty!
- */
- for (y=0; y<h; ++y)
- {
- png_const_bytep row = image[y];
- png_byte tempRow[SIZE_ROWMAX];
-
- /* If do_interlace *and* the image is interlaced we
- * need a reduced interlace row, this may be reduced
- * to empty.
- */
- if (do_interlace && interlace_type == PNG_INTERLACE_ADAM7)
- {
- /* The row must not be written if it doesn't exist, notice
- * that there are two conditions here, either the row isn't
- * ever in the pass or the row would be but isn't wide
- * enough to contribute any pixels. In fact the wPass test
- * can be used to skip the whole y loop in this case.
- */
- if (PNG_ROW_IN_INTERLACE_PASS(y, pass) && wPass > 0)
- {
- /* Set to all 1's for error detection (libpng tends to
- * set unset things to 0).
- */
- memset(tempRow, 0xff, sizeof tempRow);
- interlace_row(tempRow, row, pixel_size, w, pass);
- row = tempRow;
- }
- else
- continue;
- }
-
- /* Only get to here if the row has some pixels in it. */
- png_write_row(pp, row);
- }
- }
- }
-
- png_write_end(pp, pi);
-
- /* And store this under the appropriate id, then clean up. */
- store_storefile(ps, id);
-
- store_write_reset(ps);
- }
-
- Catch(fault)
- {
- /* Use the png_store returned by the exception. This may help the compiler
- * because 'ps' is not used in this branch of the setjmp. Note that fault
- * and ps will always be the same value.
- */
- store_write_reset(fault);
- }
-}
-
-static void
-make_size(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo,
- int PNG_CONST bdhi)
-{
- for (; bdlo <= bdhi; ++bdlo)
- {
- png_uint_32 width;
-
- for (width = 1; width <= 16; ++width)
- {
- png_uint_32 height;
-
- for (height = 1; height <= 16; ++height)
- {
- /* The four combinations of DIY interlace and interlace or not -
- * no interlace + DIY should be identical to no interlace with
- * libpng doing it.
- */
- make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE,
- width, height, 0);
- make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE,
- width, height, 1);
- make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7,
- width, height, 0);
- make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7,
- width, height, 1);
- }
- }
- }
-}
-
-static void
-make_size_images(png_store *ps)
-{
- /* This is in case of errors. */
- safecat(ps->test, sizeof ps->test, 0, "make size images");
-
- /* Arguments are colour_type, low bit depth, high bit depth
- */
- make_size(ps, 0, 0, WRITE_BDHI);
- make_size(ps, 2, 3, WRITE_BDHI);
- make_size(ps, 3, 0, 3 /*palette: max 8 bits*/);
- make_size(ps, 4, 3, WRITE_BDHI);
- make_size(ps, 6, 3, WRITE_BDHI);
-}
-
-/* Return a row based on image id and 'y' for checking: */
-static void
-standard_row(png_structp pp, png_byte std[STANDARD_ROWMAX], png_uint_32 id,
- png_uint_32 y)
-{
- if (WIDTH_FROM_ID(id) == 0)
- transform_row(pp, std, COL_FROM_ID(id), DEPTH_FROM_ID(id), y);
- else
- size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id),
- DEPTH_FROM_ID(id)), y);
-}
-
-/* Tests - individual test cases */
-/* Like 'make_standard' but errors are deliberately introduced into the calls
- * to ensure that they get detected - it should not be possible to write an
- * invalid image with libpng!
- */
-static void
-sBIT0_error_fn(png_structp pp, png_infop pi)
-{
- /* 0 is invalid... */
- png_color_8 bad;
- bad.red = bad.green = bad.blue = bad.gray = bad.alpha = 0;
- png_set_sBIT(pp, pi, &bad);
-}
-
-static void
-sBIT_error_fn(png_structp pp, png_infop pi)
-{
- png_byte bit_depth;
- png_color_8 bad;
-
- if (png_get_color_type(pp, pi) == PNG_COLOR_TYPE_PALETTE)
- bit_depth = 8;
-
- else
- bit_depth = png_get_bit_depth(pp, pi);
-
- /* Now we know the bit depth we can easily generate an invalid sBIT entry */
- bad.red = bad.green = bad.blue = bad.gray = bad.alpha =
- (png_byte)(bit_depth+1);
- png_set_sBIT(pp, pi, &bad);
-}
-
-static PNG_CONST struct
-{
- void (*fn)(png_structp, png_infop);
- PNG_CONST char *msg;
- unsigned int warning :1; /* the error is a warning... */
-} error_test[] =
- {
- { sBIT0_error_fn, "sBIT(0): failed to detect error", 1 },
- { sBIT_error_fn, "sBIT(too big): failed to detect error", 1 },
- };
-
-static void
-make_error(png_store* volatile ps, png_byte PNG_CONST colour_type,
- png_byte bit_depth, int interlace_type, int test, png_const_charp name)
-{
- context(ps, fault);
-
- Try
- {
- png_structp pp;
- png_infop pi;
-
- pp = set_store_for_write(ps, &pi, name);
-
- if (pp == NULL)
- Throw ps;
-
- png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth),
- transform_height(pp, colour_type, bit_depth), bit_depth, colour_type,
- interlace_type, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
-
- if (colour_type == 3) /* palette */
- {
- unsigned int i = 0;
- png_color pal[256];
-
- do
- pal[i].red = pal[i].green = pal[i].blue = (png_byte)i;
- while(++i < 256U);
-
- png_set_PLTE(pp, pi, pal, 256);
- }
-
- /* Time for a few errors, these are in various optional chunks, the
- * standard tests test the standard chunks pretty well.
- */
-# define exception__prev exception_prev_1
-# define exception__env exception_env_1
- Try
- {
- /* Expect this to throw: */
- ps->expect_error = !error_test[test].warning;
- ps->expect_warning = error_test[test].warning;
- ps->saw_warning = 0;
- error_test[test].fn(pp, pi);
-
- /* Normally the error is only detected here: */
- png_write_info(pp, pi);
-
- /* And handle the case where it was only a warning: */
- if (ps->expect_warning && ps->saw_warning)
- Throw ps;
-
- /* If we get here there is a problem, we have success - no error or
- * no warning - when we shouldn't have success. Log an error.
- */
- store_log(ps, pp, error_test[test].msg, 1 /*error*/);
- }
-
- Catch (fault)
- ps = fault; /* expected exit, make sure ps is not clobbered */
-#undef exception__prev
-#undef exception__env
-
- /* And clear these flags */
- ps->expect_error = 0;
- ps->expect_warning = 0;
-
- /* Now write the whole image, just to make sure that the detected, or
- * undetected, errro has not created problems inside libpng.
- */
- if (png_get_rowbytes(pp, pi) !=
- transform_rowsize(pp, colour_type, bit_depth))
- png_error(pp, "row size incorrect");
-
- else
- {
- png_uint_32 h = transform_height(pp, colour_type, bit_depth);
- int npasses = png_set_interlace_handling(pp);
- int pass;
-
- if (npasses != npasses_from_interlace_type(pp, interlace_type))
- png_error(pp, "write: png_set_interlace_handling failed");
-
- for (pass=0; pass<npasses; ++pass)
- {
- png_uint_32 y;
-
- for (y=0; y<h; ++y)
- {
- png_byte buffer[TRANSFORM_ROWMAX];
-
- transform_row(pp, buffer, colour_type, bit_depth, y);
- png_write_row(pp, buffer);
- }
- }
- }
-
- png_write_end(pp, pi);
-
- /* The following deletes the file that was just written. */
- store_write_reset(ps);
- }
-
- Catch(fault)
- {
- store_write_reset(fault);
- }
-}
-
-static int
-make_errors(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
- int bdlo, int PNG_CONST bdhi)
-{
- for (; bdlo <= bdhi; ++bdlo)
- {
- int interlace_type;
-
- for (interlace_type = PNG_INTERLACE_NONE;
- interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
- {
- unsigned int test;
- char name[FILE_NAME_SIZE];
-
- standard_name(name, sizeof name, 0, colour_type, bdlo, interlace_type,
- 0, 0, 0);
-
- for (test=0; test<(sizeof error_test)/(sizeof error_test[0]); ++test)
- {
- make_error(&pm->this, colour_type, DEPTH(bdlo), interlace_type,
- test, name);
-
- if (fail(pm))
- return 0;
- }
- }
- }
-
- return 1; /* keep going */
-}
-
-static void
-perform_error_test(png_modifier *pm)
-{
- /* Need to do this here because we just write in this test. */
- safecat(pm->this.test, sizeof pm->this.test, 0, "error test");
-
- if (!make_errors(pm, 0, 0, WRITE_BDHI))
- return;
-
- if (!make_errors(pm, 2, 3, WRITE_BDHI))
- return;
-
- if (!make_errors(pm, 3, 0, 3))
- return;
-
- if (!make_errors(pm, 4, 3, WRITE_BDHI))
- return;
-
- if (!make_errors(pm, 6, 3, WRITE_BDHI))
- return;
-}
-
-/* Because we want to use the same code in both the progressive reader and the
- * sequential reader it is necessary to deal with the fact that the progressive
- * reader callbacks only have one parameter (png_get_progressive_ptr()), so this
- * must contain all the test parameters and all the local variables directly
- * accessible to the sequential reader implementation.
- *
- * The technique adopted is to reinvent part of what Dijkstra termed a
- * 'display'; an array of pointers to the stack frames of enclosing functions so
- * that a nested function definition can access the local (C auto) variables of
- * the functions that contain its definition. In fact C provides the first
- * pointer (the local variables - the stack frame pointer) and the last (the
- * global variables - the BCPL global vector typically implemented as global
- * addresses), this code requires one more pointer to make the display - the
- * local variables (and function call parameters) of the function that actually
- * invokes either the progressive or sequential reader.
- *
- * Perhaps confusingly this technique is confounded with classes - the
- * 'standard_display' defined here is sub-classed as the 'gamma_display' below.
- * A gamma_display is a standard_display, taking advantage of the ANSI-C
- * requirement that the pointer to the first member of a structure must be the
- * same as the pointer to the structure. This allows us to reuse standard_
- * functions in the gamma test code; something that could not be done with
- * nested funtions!
- */
-typedef struct standard_palette_entry /* pngvalid format palette! */
-{
- png_byte red;
- png_byte green;
- png_byte blue;
- png_byte alpha;
-} standard_palette[256];
-
-typedef struct standard_display
-{
- png_store* ps; /* Test parameters (passed to the function) */
- png_byte colour_type;
- png_byte bit_depth;
- png_byte red_sBIT; /* Input data sBIT values. */
- png_byte green_sBIT;
- png_byte blue_sBIT;
- png_byte alpha_sBIT;
- int interlace_type;
- png_uint_32 id; /* Calculated file ID */
- png_uint_32 w; /* Width of image */
- png_uint_32 h; /* Height of image */
- int npasses; /* Number of interlaced passes */
- png_uint_32 pixel_size; /* Width of one pixel in bits */
- png_uint_32 bit_width; /* Width of output row in bits */
- size_t cbRow; /* Bytes in a row of the output image */
- int do_interlace; /* Do interlacing internally */
- int is_transparent; /* Transparecy information was present. */
- struct
- {
- png_uint_16 red;
- png_uint_16 green;
- png_uint_16 blue;
- } transparent; /* The transparent color, if set. */
- standard_palette
- palette;
-} standard_display;
-
-static void
-standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id,
- int do_interlace)
-{
- dp->ps = ps;
- dp->colour_type = COL_FROM_ID(id);
- dp->bit_depth = DEPTH_FROM_ID(id);
- dp->alpha_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT =
- dp->bit_depth;
- dp->interlace_type = INTERLACE_FROM_ID(id);
- dp->id = id;
- /* All the rest are filled in after the read_info: */
- dp->w = 0;
- dp->h = 0;
- dp->npasses = 0;
- dp->pixel_size = 0;
- dp->bit_width = 0;
- dp->cbRow = 0;
- dp->do_interlace = do_interlace;
- dp->is_transparent = 0;
- /* Preset the transparent color to black: */
- memset(&dp->transparent, 0, sizeof dp->transparent);
- /* Preset the palette to full intensity/opaque througout: */
- memset(dp->palette, 0xff, sizeof dp->palette);
-
-}
-
-/* Call this only if the colour type is 3 - PNG_COLOR_TYPE_PALETTE - otherwise
- * it will png_error out. The API returns true if tRNS information was
- * present.
- */
-static int
-standard_palette_init(standard_palette palette, png_structp pp, png_infop pi)
-{
- png_colorp pal;
- png_bytep trans_alpha;
- int num;
-
- pal = 0;
- num = -1;
- if (png_get_PLTE(pp, pi, &pal, &num) & PNG_INFO_PLTE)
- {
- int i;
-
- for (i=0; i<num; ++i)
- {
- palette[i].red = pal[i].red;
- palette[i].green = pal[i].green;
- palette[i].blue = pal[i].blue;
- }
-
- /* Mark the remainder of the entries with a flag value: */
- for (; i<256; ++i)
- palette[i].red = palette[i].green = palette[i].blue = 126;
- }
-
- else /* !png_get_PLTE */
- png_error(pp, "validate: missing PLTE with color type 3");
-
- trans_alpha = 0;
- num = -1;
- if (png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS)
- {
- int i;
-
- /* Any of these are crash-worthy - given the implementation of
- * png_get_tRNS up to 1.5 an app won't crash if it just checks the
- * result above and fails to check that the variables it passed have
- * actually been filled in! Note that if the app were to pass the
- * last, png_color_16p, variable too it couldn't rely on this.
- */
- if (trans_alpha == 0 || num <= 0 || num > 256)
- png_error(pp, "validate: unexpected png_get_tRNS (palette) result");
-
- for (i=0; i<num; ++i)
- palette[i].alpha = trans_alpha[i];
-
- for (; i<256; ++i)
- palette[i].alpha = 255;
-
- return 1; /* transparency */
- }
-
- else
- {
- /* No transparency - just set the alpha channel to opaque. */
- int i;
-
- for (i=0; i<256; ++i)
- palette[i].alpha = 255;
-
- return 0; /* no transparency */
- }
-}
-
-/* By passing a 'standard_display' the progressive callbacks can be used
- * directly by the sequential code, the functions suffixed "_imp" are the
- * implementations, the functions without the suffix are the callbacks.
- *
- * The code for the info callback is split into two because this callback calls
- * png_read_update_info or png_start_read_image and what gets called depends on
- * whether the info needs updating (we want to test both calls in pngvalid.)
- */
-static void
-standard_info_part1(standard_display *dp, png_structp pp, png_infop pi)
-{
- if (png_get_bit_depth(pp, pi) != dp->bit_depth)
- png_error(pp, "validate: bit depth changed");
-
- if (png_get_color_type(pp, pi) != dp->colour_type)
- png_error(pp, "validate: color type changed");
-
- if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE)
- png_error(pp, "validate: filter type changed");
-
- if (png_get_interlace_type(pp, pi) != dp->interlace_type)
- png_error(pp, "validate: interlacing changed");
-
- if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE)
- png_error(pp, "validate: compression type changed");
-
- dp->w = png_get_image_width(pp, pi);
-
- if (dp->w != standard_width(pp, dp->id))
- png_error(pp, "validate: image width changed");
-
- dp->h = png_get_image_height(pp, pi);
-
- if (dp->h != standard_height(pp, dp->id))
- png_error(pp, "validate: image height changed");
-
- /* Record (but don't check at present) the input sBIT according to the colour
- * type information.
- */
- {
- png_color_8p sBIT = 0;
-
- if (png_get_sBIT(pp, pi, &sBIT) & PNG_INFO_sBIT)
- {
- int sBIT_invalid = 0;
-
- if (sBIT == 0)
- png_error(pp, "validate: unexpected png_get_sBIT result");
-
- if (dp->colour_type & PNG_COLOR_MASK_COLOR)
- {
- if (sBIT->red == 0 || sBIT->red > dp->bit_depth)
- sBIT_invalid = 1;
- else
- dp->red_sBIT = sBIT->red;
-
- if (sBIT->green == 0 || sBIT->green > dp->bit_depth)
- sBIT_invalid = 1;
- else
- dp->green_sBIT = sBIT->green;
-
- if (sBIT->blue == 0 || sBIT->blue > dp->bit_depth)
- sBIT_invalid = 1;
- else
- dp->blue_sBIT = sBIT->blue;
- }
-
- else /* !COLOR */
- {
- if (sBIT->gray == 0 || sBIT->gray > dp->bit_depth)
- sBIT_invalid = 1;
- else
- dp->blue_sBIT = dp->green_sBIT = dp->red_sBIT = sBIT->gray;
- }
-
- /* All 8 bits in tRNS for a palette image are significant - see the
- * spec.
- */
- if (dp->colour_type & PNG_COLOR_MASK_ALPHA)
- {
- if (sBIT->alpha == 0 || sBIT->alpha > dp->bit_depth)
- sBIT_invalid = 1;
- else
- dp->alpha_sBIT = sBIT->alpha;
- }
-
- if (sBIT_invalid)
- png_error(pp, "validate: sBIT value out of range");
- }
- }
-
- /* Important: this is validating the value *before* any transforms have been
- * put in place. It doesn't matter for the standard tests, where there are
- * no transforms, but it does for other tests where rowbytes may change after
- * png_read_update_info.
- */
- if (png_get_rowbytes(pp, pi) != standard_rowsize(pp, dp->id))
- png_error(pp, "validate: row size changed");
-
- /* The palette is never read for non-palette images, even though it is valid
- * - this could be changed.
- */
- if (dp->colour_type == 3) /* palette */
- {
- int i;
-
- dp->is_transparent = standard_palette_init(dp->palette, pp, pi);
-
- /* And validate the result. */
- for (i=0; i<256; ++i)
- if (dp->palette[i].red != i || dp->palette[i].green != i ||
- dp->palette[i].blue != i)
- png_error(pp, "validate: color type 3 PLTE chunk changed");
- }
-
- /* In any case always check for a tranparent color: */
- {
- png_color_16p trans_color = 0;
-
- if (png_get_tRNS(pp, pi, 0, 0, &trans_color) & PNG_INFO_tRNS)
- {
- if (trans_color == 0)
- png_error(pp, "validate: unexpected png_get_tRNS (color) result");
-
- switch (dp->colour_type)
- {
- case 0:
- dp->transparent.red = dp->transparent.green = dp->transparent.blue =
- trans_color->gray;
- dp->is_transparent = 1;
- break;
-
- case 2:
- dp->transparent.red = trans_color->red;
- dp->transparent.green = trans_color->green;
- dp->transparent.blue = trans_color->blue;
- dp->is_transparent = 1;
- break;
-
- case 3:
- /* Not expected because it should result in the array case
- * above.
- */
- png_error(pp, "validate: unexpected png_get_tRNS result");
- break;
-
- default:
- png_error(pp, "validate: invalid tRNS chunk with alpha image");
- }
- }
- }
-
- /* Read the number of passes - expected to match the value used when
- * creating the image (interlaced or not). This has the side effect of
- * turning on interlace handling (if do_interlace is not set.)
- */
- dp->npasses = npasses_from_interlace_type(pp, dp->interlace_type);
- if (!dp->do_interlace && dp->npasses != png_set_interlace_handling(pp))
- png_error(pp, "validate: file changed interlace type");
-
- /* Caller calls png_read_update_info or png_start_read_image now, then calls
- * part2.
- */
-}
-
-/* This must be called *after* the png_read_update_info call to get the correct
- * 'rowbytes' value, otherwise png_get_rowbytes will refer to the untransformed
- * image.
- */
-static void
-standard_info_part2(standard_display *dp, png_structp pp, png_infop pi,
- int nImages)
-{
- /* Record cbRow now that it can be found. */
- dp->pixel_size = bit_size(pp, png_get_color_type(pp, pi),
- png_get_bit_depth(pp, pi));
- dp->bit_width = png_get_image_width(pp, pi) * dp->pixel_size;
- dp->cbRow = png_get_rowbytes(pp, pi);
-
- /* Validate the rowbytes here again. */
- if (dp->cbRow != (dp->bit_width+7)/8)
- png_error(pp, "bad png_get_rowbytes calculation");
-
- /* Then ensure there is enough space for the output image(s). */
- store_ensure_image(dp->ps, pp, nImages * dp->cbRow * dp->h);
-}
-
-static void
-standard_info_imp(standard_display *dp, png_structp pp, png_infop pi,
- int nImages)
-{
- /* Note that the validation routine has the side effect of turning on
- * interlace handling in the subsequent code.
- */
- standard_info_part1(dp, pp, pi);
-
- /* And the info callback has to call this (or png_read_update_info - see
- * below in the png_modifier code for that variant.
- */
- png_start_read_image(pp);
-
- /* Validate the height, width and rowbytes plus ensure that sufficient buffer
- * exists for decoding the image.
- */
- standard_info_part2(dp, pp, pi, nImages);
-}
-
-static void
-standard_info(png_structp pp, png_infop pi)
-{
- standard_display *dp = png_get_progressive_ptr(pp);
-
- /* Call with nImages==1 because the progressive reader can only produce one
- * image.
- */
- standard_info_imp(dp, pp, pi, 1 /*only one image*/);
-}
-
-static void
-progressive_row(png_structp pp, png_bytep new_row, png_uint_32 y, int pass)
-{
- PNG_CONST standard_display *dp = png_get_progressive_ptr(pp);
-
- /* When handling interlacing some rows will be absent in each pass, the
- * callback still gets called, but with a NULL pointer. This is checked
- * in the 'else' clause below. We need our own 'cbRow', but we can't call
- * png_get_rowbytes because we got no info structure.
- */
- if (new_row != NULL)
- {
- png_bytep row;
-
- /* In the case where the reader doesn't do the interlace it gives
- * us the y in the sub-image:
- */
- if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7)
- y = PNG_ROW_FROM_PASS_ROW(y, pass);
-
- /* Validate this just in case. */
- if (y >= dp->h)
- png_error(pp, "invalid y to progressive row callback");
-
- row = dp->ps->image + y * dp->cbRow;
-
- /* Combine the new row into the old: */
- if (dp->do_interlace)
- {
- if (dp->interlace_type == PNG_INTERLACE_ADAM7)
- deinterlace_row(row, new_row, dp->pixel_size, dp->w, pass);
- else
- memcpy(row, new_row, dp->cbRow);
- }
- else
- png_progressive_combine_row(pp, row, new_row);
- } else if (dp->interlace_type == PNG_INTERLACE_ADAM7 &&
- PNG_ROW_IN_INTERLACE_PASS(y, pass) &&
- PNG_PASS_COLS(dp->w, pass) > 0)
- png_error(pp, "missing row in progressive de-interlacing");
-}
-
-static void
-sequential_row(standard_display *dp, png_structp pp, png_infop pi,
- PNG_CONST png_bytep pImage, PNG_CONST png_bytep pDisplay)
-{
- PNG_CONST int npasses = dp->npasses;
- PNG_CONST int do_interlace = dp->do_interlace &&
- dp->interlace_type == PNG_INTERLACE_ADAM7;
- PNG_CONST png_uint_32 height = standard_height(pp, dp->id);
- PNG_CONST png_uint_32 width = standard_width(pp, dp->id);
- PNG_CONST size_t cbRow = dp->cbRow;
- int pass;
-
- for (pass=0; pass<npasses; ++pass)
- {
- png_uint_32 y;
- png_uint_32 wPass = PNG_PASS_COLS(width, pass);
- png_bytep pRow1 = pImage;
- png_bytep pRow2 = pDisplay;
-
- for (y=0; y<height; ++y)
- {
- if (do_interlace)
- {
- /* wPass may be zero or this row may not be in this pass.
- * png_read_row must not be called in either case.
- */
- if (wPass > 0 && PNG_ROW_IN_INTERLACE_PASS(y, pass))
- {
- /* Read the row into a pair of temporary buffers, then do the
- * merge here into the output rows.
- */
- png_byte row[STANDARD_ROWMAX], display[STANDARD_ROWMAX];
-
- /* The following aids (to some extent) error detection - we can
- * see where png_read_row wrote. Use opposite values in row and
- * display to make this easier.
- */
- memset(row, 0xff, sizeof row);
- memset(display, 0, sizeof display);
-
- png_read_row(pp, row, display);
-
- if (pRow1 != NULL)
- deinterlace_row(pRow1, row, dp->pixel_size, dp->w, pass);
-
- if (pRow2 != NULL)
- deinterlace_row(pRow2, display, dp->pixel_size, dp->w, pass);
- }
- }
- else
- png_read_row(pp, pRow1, pRow2);
-
- if (pRow1 != NULL)
- pRow1 += cbRow;
-
- if (pRow2 != NULL)
- pRow2 += cbRow;
- }
- }
-
- /* And finish the read operation (only really necessary if the caller wants
- * to find additional data in png_info from chunks after the last IDAT.)
- */
- png_read_end(pp, pi);
-}
-
-static void
-standard_row_validate(standard_display *dp, png_structp pp, png_const_bytep row,
- png_const_bytep display, png_uint_32 y)
-{
- png_byte std[STANDARD_ROWMAX];
-
- memset(std, 0xff, sizeof std);
- standard_row(pp, std, dp->id, y);
-
- /* At the end both the 'row' and 'display' arrays should end up identical.
- * In earlier passes 'row' will be partially filled in, with only the pixels
- * that have been read so far, but 'display' will have those pixels
- * replicated to fill the unread pixels while reading an interlaced image.
- * The side effect inside the libpng sequential reader is that the 'row'
- * array retains the correct values for unwritten pixels within the row
- * bytes, while the 'display' array gets bits off the end of the image (in
- * the last byte) trashed. Unfortunately in the progressive reader the
- * row bytes are always trashed, so we always do a pixel_cmp here even though
- * a memcmp of all cbRow bytes will succeed for the sequential reader.
- */
- if (row != NULL && pixel_cmp(std, row, dp->bit_width) != 0)
- {
- char msg[64];
- sprintf(msg, "PNG image row %d changed", y);
- png_error(pp, msg);
- }
-
- /* In this case use pixel_cmp because we need to compare a partial
- * byte at the end of the row if the row is not an exact multiple
- * of 8 bits wide.
- */
- if (display != NULL && pixel_cmp(std, display, dp->bit_width) != 0)
- {
- char msg[64];
- sprintf(msg, "display row %d changed", y);
- png_error(pp, msg);
- }
-}
-
-static void
-standard_image_validate(standard_display *dp, png_structp pp,
- png_const_bytep pImage, png_const_bytep pDisplay)
-{
- png_uint_32 y;
-
- for (y=0; y<dp->h; ++y)
- {
- standard_row_validate(dp, pp, pImage, pDisplay, y);
-
- if (pImage != NULL)
- pImage += dp->cbRow;
-
- if (pDisplay != NULL)
- pDisplay += dp->cbRow;
- }
-
- /* This avoids false positives if the validation code is never called! */
- dp->ps->validated = 1;
-}
-
-static void
-standard_end(png_structp pp, png_infop pi)
-{
- standard_display *dp = png_get_progressive_ptr(pp);
-
- UNUSED(pi)
-
- /* Validate the image - progressive reading only produces one variant for
- * interlaced images.
- */
- standard_image_validate(dp, pp, dp->ps->image, NULL);
-}
-
-/* A single test run checking the standard image to ensure it is not damaged. */
-static void
-standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id,
- int do_interlace)
-{
- standard_display d;
- context(psIn, fault);
-
- /* Set up the display (stack frame) variables from the arguments to the
- * function and initialize the locals that are filled in later.
- */
- standard_display_init(&d, psIn, id, do_interlace);
-
- /* Everything is protected by a Try/Catch. The functions called also
- * typically have local Try/Catch blocks.
- */
- Try
- {
- png_structp pp;
- png_infop pi;
-
- /* Get a png_struct for reading the image. This will throw an error if it
- * fails, so we don't need to check the result.
- */
- pp = set_store_for_read(d.ps, &pi, d.id,
- d.do_interlace ? (d.ps->progressive ?
- "pngvalid progressive deinterlacer" :
- "pngvalid sequential deinterlacer") : (d.ps->progressive ?
- "progressive reader" : "sequential reader"));
-
- /* Introduce the correct read function. */
- if (d.ps->progressive)
- {
- png_set_progressive_read_fn(pp, &d, standard_info, progressive_row,
- standard_end);
-
- /* Now feed data into the reader until we reach the end: */
- store_progressive_read(d.ps, pp, pi);
- }
- else
- {
- /* Note that this takes the store, not the display. */
- png_set_read_fn(pp, d.ps, store_read);
-
- /* Check the header values: */
- png_read_info(pp, pi);
-
- /* The code tests both versions of the images that the sequential
- * reader can produce.
- */
- standard_info_imp(&d, pp, pi, 2 /*images*/);
-
- /* Need the total bytes in the image below; we can't get to this point
- * unless the PNG file values have been checked against the expected
- * values.
- */
- {
- PNG_CONST png_bytep pImage = d.ps->image;
- PNG_CONST png_bytep pDisplay = pImage + d.cbRow * d.h;
-
- sequential_row(&d, pp, pi, pImage, pDisplay);
-
- /* After the last pass loop over the rows again to check that the
- * image is correct.
- */
- standard_image_validate(&d, pp, pImage, pDisplay);
- }
- }
-
- /* Check for validation. */
- if (!d.ps->validated)
- png_error(pp, "image read failed silently");
-
- /* Successful completion. */
- }
-
- Catch(fault)
- d.ps = fault; /* make sure this hasn't been clobbered. */
-
- /* In either case clean up the store. */
- store_read_reset(d.ps);
-}
-
-static int
-test_standard(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
- int bdlo, int PNG_CONST bdhi)
-{
- for (; bdlo <= bdhi; ++bdlo)
- {
- int interlace_type;
-
- for (interlace_type = PNG_INTERLACE_NONE;
- interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
- {
- standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
- interlace_type, 0, 0, 0), 0/*do_interlace*/);
-
- if (fail(pm))
- return 0;
- }
- }
-
- return 1; /* keep going */
-}
-
-static void
-perform_standard_test(png_modifier *pm)
-{
- /* Test each colour type over the valid range of bit depths (expressed as
- * log2(bit_depth) in turn, stop as soon as any error is detected.
- */
- if (!test_standard(pm, 0, 0, READ_BDHI))
- return;
-
- if (!test_standard(pm, 2, 3, READ_BDHI))
- return;
-
- if (!test_standard(pm, 3, 0, 3))
- return;
-
- if (!test_standard(pm, 4, 3, READ_BDHI))
- return;
-
- if (!test_standard(pm, 6, 3, READ_BDHI))
- return;
-}
-
-
-/********************************** SIZE TESTS ********************************/
-static int
-test_size(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
- int bdlo, int PNG_CONST bdhi)
-{
- /* Run the tests on each combination.
- *
- * NOTE: on my 32 bit x86 each of the following blocks takes
- * a total of 3.5 seconds if done across every combo of bit depth
- * width and height. This is a waste of time in practice, hence the
- * hinc and winc stuff:
- */
- static PNG_CONST png_byte hinc[] = {1, 3, 11, 1, 5};
- static PNG_CONST png_byte winc[] = {1, 9, 5, 7, 1};
- for (; bdlo <= bdhi; ++bdlo)
- {
- png_uint_32 h, w;
-
- for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo])
- {
- /* First test all the 'size' images against the sequential
- * reader using libpng to deinterlace (where required.) This
- * validates the write side of libpng. There are four possibilities
- * to validate.
- */
- standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
- PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/);
-
- if (fail(pm))
- return 0;
-
- standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
- PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/);
-
- if (fail(pm))
- return 0;
-
- standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
- PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/);
-
- if (fail(pm))
- return 0;
-
- standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
- PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/);
-
- if (fail(pm))
- return 0;
-
- /* Now validate the interlaced read side - do_interlace true,
- * in the progressive case this does actually make a difference
- * to the code used in the non-interlaced case too.
- */
- standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
- PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/);
-
- if (fail(pm))
- return 0;
-
- standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
- PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/);
-
- if (fail(pm))
- return 0;
- }
- }
-
- return 1; /* keep going */
-}
-
-static void
-perform_size_test(png_modifier *pm)
-{
- /* Test each colour type over the valid range of bit depths (expressed as
- * log2(bit_depth) in turn, stop as soon as any error is detected.
- */
- if (!test_size(pm, 0, 0, READ_BDHI))
- return;
-
- if (!test_size(pm, 2, 3, READ_BDHI))
- return;
-
- /* For the moment don't do the palette test - it's a waste of time when
- * compared to the greyscale test.
- */
-#if 0
- if (!test_size(pm, 3, 0, 3))
- return;
-#endif
-
- if (!test_size(pm, 4, 3, READ_BDHI))
- return;
-
- if (!test_size(pm, 6, 3, READ_BDHI))
- return;
-}
-
-
-/******************************* TRANSFORM TESTS ******************************/
-/* A set of tests to validate libpng image transforms. The possibilities here
- * are legion because the transforms can be combined in a combinatorial
- * fashion. To deal with this some measure of restraint is required, otherwise
- * the tests would take forever.
- */
-typedef struct image_pixel
-{
- /* A local (pngvalid) representation of a PNG pixel, in all its
- * various forms.
- */
- unsigned int red, green, blue, alpha; /* For non-palette images. */
- unsigned int palette_index; /* For a palette image. */
- png_byte colour_type; /* As in the spec. */
- png_byte bit_depth; /* Defines bit size in row */
- png_byte sample_depth; /* Scale of samples */
- int have_tRNS; /* tRNS chunk may need processing */
-
- /* For checking the code calculates double precision floating point values
- * along with an error value, accumulated from the transforms. Because an
- * sBIT setting allows larger error bounds (indeed, by the spec, apparently
- * up to just less than +/-1 in the scaled value) the *lowest* sBIT for each
- * channel is stored. This sBIT value is folded in to the stored error value
- * at the end of the application of the transforms to the pixel.
- */
- double redf, greenf, bluef, alphaf;
- double rede, greene, bluee, alphae;
- png_byte red_sBIT, green_sBIT, blue_sBIT, alpha_sBIT;
-} image_pixel;
-
-/* Shared utility function, see below. */
-static void
-image_pixel_setf(image_pixel *this, unsigned int max)
-{
- this->redf = this->red / (double)max;
- this->greenf = this->green / (double)max;
- this->bluef = this->blue / (double)max;
- this->alphaf = this->alpha / (double)max;
-
- if (this->red < max)
- this->rede = this->redf * DBL_EPSILON;
- else
- this->rede = 0;
- if (this->green < max)
- this->greene = this->greenf * DBL_EPSILON;
- else
- this->greene = 0;
- if (this->blue < max)
- this->bluee = this->bluef * DBL_EPSILON;
- else
- this->bluee = 0;
- if (this->alpha < max)
- this->alphae = this->alphaf * DBL_EPSILON;
- else
- this->alphae = 0;
-}
-
-/* Initialize the structure for the next pixel - call this before doing any
- * transforms and call it for each pixel since all the fields may need to be
- * reset.
- */
-static void
-image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type,
- png_byte bit_depth, png_uint_32 x, standard_palette palette)
-{
- PNG_CONST png_byte sample_depth = (png_byte)(colour_type ==
- PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth);
- PNG_CONST unsigned int max = (1U<<sample_depth)-1;
-
- /* Initially just set everything to the same number and the alpha to opaque.
- * Note that this currently assumes a simple palette where entry x has colour
- * rgb(x,x,x)!
- */
- this->palette_index = this->red = this->green = this->blue =
- sample(row, colour_type, bit_depth, x, 0);
- this->alpha = max;
- this->red_sBIT = this->green_sBIT = this->blue_sBIT = this->alpha_sBIT =
- sample_depth;
-
- /* Then override as appropriate: */
- if (colour_type == 3) /* palette */
- {
- /* This permits the caller to default to the sample value. */
- if (palette != 0)
- {
- PNG_CONST unsigned int i = this->palette_index;
-
- this->red = palette[i].red;
- this->green = palette[i].green;
- this->blue = palette[i].blue;
- this->alpha = palette[i].alpha;
- }
- }
-
- else /* not palette */
- {
- unsigned int i = 0;
-
- if (colour_type & 2)
- {
- this->green = sample(row, colour_type, bit_depth, x, 1);
- this->blue = sample(row, colour_type, bit_depth, x, 2);
- i = 2;
- }
- if (colour_type & 4)
- this->alpha = sample(row, colour_type, bit_depth, x, ++i);
- }
-
- /* Calculate the scaled values, these are simply the values divided by
- * 'max' and the error is initialized to the double precision epsilon value
- * from the header file.
- */
- image_pixel_setf(this, max);
-
- /* Store the input information for use in the transforms - these will
- * modify the information.
- */
- this->colour_type = colour_type;
- this->bit_depth = bit_depth;
- this->sample_depth = sample_depth;
- this->have_tRNS = 0;
-}
-
-/* Convert a palette image to an rgb image. This necessarily converts the tRNS
- * chunk at the same time, because the tRNS will be in palette form.
- */
-static void
-image_pixel_convert_PLTE(image_pixel *this, const standard_display *display)
-{
- if (this->colour_type == PNG_COLOR_TYPE_PALETTE)
- {
- PNG_CONST unsigned int i = this->palette_index;
-
- this->bit_depth = this->sample_depth;
- this->red = display->palette[i].red;
- this->green = display->palette[i].green;
- this->blue = display->palette[i].blue;
- this->red_sBIT = display->red_sBIT;
- this->green_sBIT = display->green_sBIT;
- this->blue_sBIT = display->blue_sBIT;
-
- if (this->have_tRNS)
- {
- this->alpha = display->palette[i].alpha;
- this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
- this->have_tRNS = 0;
- }
- else
- {
- this->alpha = 255;
- this->colour_type = PNG_COLOR_TYPE_RGB;
- }
- this->alpha_sBIT = 8;
-
- /* And regenerate the scaled values and all the errors, which are now set
- * back to the initial values.
- */
- image_pixel_setf(this, 255);
- }
-}
-
-/* Add an alpha channel, this will glom in the tRNS information because tRNS is
- * not valid in an alpha image. The bit depth will invariably be set to at
- * least 8. Palette images will be converted to alpha (using the above API).
- */
-static void
-image_pixel_add_alpha(image_pixel *this, const standard_display *display)
-{
- if (this->colour_type == PNG_COLOR_TYPE_PALETTE)
- image_pixel_convert_PLTE(this, display);
-
- if ((this->colour_type & PNG_COLOR_MASK_ALPHA) == 0)
- {
- if (this->colour_type == PNG_COLOR_TYPE_GRAY)
- {
- if (this->bit_depth < 8)
- this->bit_depth = 8;
-
- if (this->have_tRNS)
- {
- this->have_tRNS = 0;
-
- /* Check the input, original, channel value here against the
- * original tRNS gray chunk valie.
- */
- if (this->red == display->transparent.red)
- this->alphaf = 0;
- else
- this->alphaf = 1;
- }
- else
- this->alphaf = 1;
-
- this->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA;
- }
-
- else if (this->colour_type == PNG_COLOR_TYPE_RGB)
- {
- if (this->have_tRNS)
- {
- this->have_tRNS = 0;
-
- /* Again, check the exact input values, not the current transformed
- * value!
- */
- if (this->red == display->transparent.red &&
- this->green == display->transparent.green &&
- this->blue == display->transparent.blue)
- this->alphaf = 0;
- else
- this->alphaf = 1;
-
- this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
- }
- }
-
- /* The error in the alpha is zero and the sBIT value comes from the
- * original sBIT data (actually it will always be the original bit depth).
- */
- this->alphae = 0;
- this->alpha_sBIT = display->alpha_sBIT;
- }
-}
-
-struct transform_display;
-typedef struct image_transform
-{
- /* The name of this transform: a string. */
- PNG_CONST char *name;
-
- /* Each transform can be disabled from the command line: */
- int enable;
-
- /* The global list of transforms; read only. */
- struct image_transform *PNG_CONST list;
-
- /* The global count of the number of times this transform has been set on an
- * image.
- */
- unsigned int global_use;
-
- /* The local count of the number of times this transform has been set. */
- unsigned int local_use;
-
- /* The next transform in the list, each transform must call its own next
- * transform after it has processed the pixel successfully.
- */
- PNG_CONST struct image_transform *next;
-
- /* A single transform for the image, expressed as a series of function
- * callbacks and some space for values.
- *
- * First a callback to set the transform on the current png_read_struct:
- */
- void (*set)(PNG_CONST struct image_transform *this,
- struct transform_display *that, png_structp pp, png_infop pi);
-
- /* Then a transform that takes an input pixel in one PNG format or another
- * and modifies it by a pngvalid implementation of the transform (thus
- * duplicating the libpng intent without, we hope, duplicating the bugs
- * in the libpng implementation!) The png_structp is solely to allow error
- * reporting via png_error and png_warning.
- */
- void (*mod)(PNG_CONST struct image_transform *this, image_pixel *that,
- png_structp pp, PNG_CONST struct transform_display *display);
-
- /* Add this transform to the list and return true if the transform is
- * meaningful for this colour type and bit depth - if false then the
- * transform should have no effect on the image so there's not a lot of
- * point running it.
- */
- int (*add)(struct image_transform *this,
- PNG_CONST struct image_transform **that, png_byte colour_type,
- png_byte bit_depth);
-} image_transform;
-
-typedef struct transform_display
-{
- standard_display this;
-
- /* Parameters */
- png_modifier* pm;
- PNG_CONST image_transform* transform_list;
-
- /* Local variables */
- png_byte output_colour_type;
- png_byte output_bit_depth;
-} transform_display;
-
-/* Two functions to end the list: */
-static void
-image_transform_set_end(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- UNUSED(this)
- UNUSED(that)
- UNUSED(pp)
- UNUSED(pi)
-}
-
-/* At the end of the list recalculate the output image pixel value from the
- * double precision values set up by the preceding 'mod' calls:
- */
-static unsigned int
-sample_scale(double sample_value, unsigned int scale)
-{
- sample_value = floor(sample_value * scale + .5);
-
- /* Return NaN as 0: */
- if (!(sample_value > 0))
- sample_value = 0;
- else if (sample_value > scale)
- sample_value = scale;
-
- return (unsigned int)sample_value;
-}
-
-static void
-image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that,
- png_structp pp, PNG_CONST transform_display *display)
-{
- PNG_CONST unsigned int scale = (1U<<that->sample_depth)-1;
-
- UNUSED(this)
- UNUSED(pp)
- UNUSED(display)
-
- /* At the end recalculate the digitized red green and blue values according
- * to the current sample_depth of the pixel.
- *
- * The sample value is simply scaled to the maximum, checking for over
- * and underflow (which can both happen for some image transforms,
- * including simple size scaling, though libpng doesn't do that at present.
- */
- that->red = sample_scale(that->redf, scale);
-
- /* The error value is increased, at the end, according to the lowest sBIT
- * value seen. Common sense tells us that the intermediate integer
- * representations are no more accurate than +/- 0.5 in the integral values,
- * the sBIT allows the implementation to be worse than this. In addition the
- * PNG specification actually permits any error within the range (-1..+1),
- * but that is ignored here. Instead the final digitized value is compared,
- * below to the digitized value of the error limits - this has the net effect
- * of allowing (almost) +/-1 in the output value. It's difficult to see how
- * any algorithm that digitizes intermediate results can be more accurate.
- */
- that->rede += 1./(2*((1U<<that->red_sBIT)-1));
-
- if (that->colour_type & PNG_COLOR_MASK_COLOR)
- {
- that->green = sample_scale(that->greenf, scale);
- that->blue = sample_scale(that->bluef, scale);
- that->greene += 1./(2*((1U<<that->green_sBIT)-1));
- that->bluee += 1./(2*((1U<<that->blue_sBIT)-1));
- }
- else
- {
- that->blue = that->green = that->red;
- that->bluef = that->greenf = that->redf;
- that->bluee = that->greene = that->rede;
- }
-
- if ((that->colour_type & PNG_COLOR_MASK_ALPHA) ||
- that->colour_type == PNG_COLOR_TYPE_PALETTE)
- {
- that->alpha = sample_scale(that->alphaf, scale);
- that->alphae += 1./(2*((1U<<that->alpha_sBIT)-1));
- }
- else
- {
- that->alpha = scale; /* opaque */
- that->alpha = 1; /* Override this. */
- that->alphae = 0; /* It's exact ;-) */
- }
-}
-
-/* Static 'end' structure: */
-static image_transform image_transform_end =
-{
- "(end)", /* name */
- 1, /* enable */
- 0, /* list */
- 0, /* global_use */
- 0, /* local_use */
- 0, /* next */
- image_transform_set_end,
- image_transform_mod_end,
- 0 /* never called, I want it to crash if it is! */
-};
-
-/* Reader callbacks and implementations, where they differ from the standard
- * ones.
- */
-static void
-transform_display_init(transform_display *dp, png_modifier *pm, png_uint_32 id,
- PNG_CONST image_transform *transform_list)
-{
- /* Standard fields */
- standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/);
-
- /* Parameter fields */
- dp->pm = pm;
- dp->transform_list = transform_list;
-
- /* Local variable fields */
- dp->output_colour_type = 255; /* invalid */
- dp->output_bit_depth = 255; /* invalid */
-}
-
-static void
-transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
-{
- /* Reuse the standard stuff as appropriate. */
- standard_info_part1(&dp->this, pp, pi);
-
- /* Now set the list of transforms. */
- dp->transform_list->set(dp->transform_list, dp, pp, pi);
-
- /* Update the info structure for these transforms: */
- png_read_update_info(pp, pi);
-
- /* And get the output information into the standard_display */
- standard_info_part2(&dp->this, pp, pi, 1/*images*/);
-
- /* Plus the extra stuff we need for the transform tests: */
- dp->output_colour_type = png_get_color_type(pp, pi);
- dp->output_bit_depth = png_get_bit_depth(pp, pi);
-
- /* Validate the combination of colour type and bit depth that we are getting
- * out of libpng; the semantics of something not in the PNG spec are, at
- * best, unclear.
- */
- switch (dp->output_colour_type)
- {
- case PNG_COLOR_TYPE_PALETTE:
- if (dp->output_bit_depth > 8) goto error;
- /*FALL THROUGH*/
- case PNG_COLOR_TYPE_GRAY:
- if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 ||
- dp->output_bit_depth == 4)
- break;
- /*FALL THROUGH*/
- default:
- if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16)
- break;
- /*FALL THROUGH*/
- error:
- {
- char message[128];
- size_t pos;
-
- pos = safecat(message, sizeof message, 0,
- "invalid final bit depth: colour type(");
- pos = safecatn(message, sizeof message, pos, dp->output_colour_type);
- pos = safecat(message, sizeof message, pos, ") with bit depth: ");
- pos = safecatn(message, sizeof message, pos, dp->output_bit_depth);
-
- png_error(pp, message);
- }
- }
-
- /* Use a test pixel to check that the output agrees with what we expect -
- * this avoids running the whole test if the output is unexpected.
- */
- {
- image_pixel test_pixel;
-
- memset(&test_pixel, 0, sizeof test_pixel);
- test_pixel.colour_type = dp->this.colour_type; /* input */
- test_pixel.bit_depth = dp->this.bit_depth;
- if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE)
- test_pixel.sample_depth = 8;
- else
- test_pixel.sample_depth = test_pixel.bit_depth;
- /* Don't need sBIT here */
- test_pixel.have_tRNS = dp->this.is_transparent;
-
- dp->transform_list->mod(dp->transform_list, &test_pixel, pp, dp);
-
- if (test_pixel.colour_type != dp->output_colour_type)
- {
- char message[128];
- size_t pos = safecat(message, sizeof message, 0, "colour type ");
-
- pos = safecatn(message, sizeof message, pos, dp->output_colour_type);
- pos = safecat(message, sizeof message, pos, " expected ");
- pos = safecatn(message, sizeof message, pos, test_pixel.colour_type);
-
- png_error(pp, message);
- }
-
- if (test_pixel.bit_depth != dp->output_bit_depth)
- {
- char message[128];
- size_t pos = safecat(message, sizeof message, 0, "bit depth ");
-
- pos = safecatn(message, sizeof message, pos, dp->output_bit_depth);
- pos = safecat(message, sizeof message, pos, " expected ");
- pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth);
-
- png_error(pp, message);
- }
-
- /* If both bit depth and colour type are correct check the sample depth.
- * I believe these are both internal errors.
- */
- if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (test_pixel.sample_depth != 8) /* oops - internal error! */
- png_error(pp, "pngvalid: internal: palette sample depth not 8");
- }
- else if (test_pixel.sample_depth != dp->output_bit_depth)
- {
- char message[128];
- size_t pos = safecat(message, sizeof message, 0,
- "internal: sample depth ");
-
- pos = safecatn(message, sizeof message, pos, dp->output_bit_depth);
- pos = safecat(message, sizeof message, pos, " expected ");
- pos = safecatn(message, sizeof message, pos, test_pixel.sample_depth);
-
- png_error(pp, message);
- }
- }
-}
-
-static void
-transform_info(png_structp pp, png_infop pi)
-{
- transform_info_imp(png_get_progressive_ptr(pp), pp, pi);
-}
-
-static void
-transform_range_check(png_structp pp, unsigned int r, unsigned int g,
- unsigned int b, unsigned int a, unsigned int in_digitized, double in,
- unsigned int out, png_byte sample_depth, double err, PNG_CONST char *name)
-{
- /* Compare the scaled, digitzed, values of our local calculation (in+-err)
- * with the digitized values libpng produced; 'sample_depth' is the actual
- * digitization depth of the libpng output colors (the bit depth except for
- * palette images where it is always 8.)
- */
- unsigned int max = (1U<<sample_depth)-1;
- double in_min = ceil((in-err)*max - .5);
- double in_max = floor((in+err)*max + .5);
- if (!(out >= in_min && out <= in_max))
- {
- char message[256];
- size_t pos;
-
- pos = safecat(message, sizeof message, 0, name);
- pos = safecat(message, sizeof message, pos, " output value error: rgba(");
- pos = safecatn(message, sizeof message, pos, r);
- pos = safecat(message, sizeof message, pos, ",");
- pos = safecatn(message, sizeof message, pos, g);
- pos = safecat(message, sizeof message, pos, ",");
- pos = safecatn(message, sizeof message, pos, b);
- pos = safecat(message, sizeof message, pos, ",");
- pos = safecatn(message, sizeof message, pos, a);
- pos = safecat(message, sizeof message, pos, "): ");
- pos = safecatn(message, sizeof message, pos, out);
- pos = safecat(message, sizeof message, pos, " expected: ");
- pos = safecatn(message, sizeof message, pos, in_digitized);
- pos = safecat(message, sizeof message, pos, " (");
- pos = safecatd(message, sizeof message, pos, (in-err)*max, 3);
- pos = safecat(message, sizeof message, pos, "..");
- pos = safecatd(message, sizeof message, pos, (in+err)*max, 3);
- pos = safecat(message, sizeof message, pos, ")");
-
- png_error(pp, message);
- }
-}
-
-static void
-transform_image_validate(transform_display *dp, png_structp pp, png_infop pi,
- png_const_bytep pRow)
-{
- /* Constants for the loop below: */
- PNG_CONST png_byte in_ct = dp->this.colour_type;
- PNG_CONST png_byte in_bd = dp->this.bit_depth;
- PNG_CONST png_uint_32 w = dp->this.w;
- PNG_CONST png_uint_32 h = dp->this.h;
- PNG_CONST size_t cbRow = dp->this.cbRow;
- PNG_CONST png_byte out_ct = dp->output_colour_type;
- PNG_CONST png_byte out_bd = dp->output_bit_depth;
- PNG_CONST png_byte sample_depth = (png_byte)(out_ct ==
- PNG_COLOR_TYPE_PALETTE ? 8 : out_bd);
- PNG_CONST png_byte red_sBIT = dp->this.red_sBIT;
- PNG_CONST png_byte green_sBIT = dp->this.green_sBIT;
- PNG_CONST png_byte blue_sBIT = dp->this.blue_sBIT;
- PNG_CONST png_byte alpha_sBIT = dp->this.alpha_sBIT;
- PNG_CONST int have_tRNS = dp->this.is_transparent;
-
- standard_palette out_palette;
- png_uint_32 y;
-
- UNUSED(pi)
-
- /* Read the palette corresponding to the output if the output colour type
- * indicates a palette, othewise set out_palette to garbage.
- */
- if (out_ct == PNG_COLOR_TYPE_PALETTE)
- (void)standard_palette_init(out_palette, pp, pi);
- else
- memset(out_palette, 0x5e, sizeof out_palette);
-
- for (y=0; y<h; ++y, pRow += cbRow)
- {
- png_uint_32 x;
-
- /* The original, standard, row pre-transforms. */
- png_byte std[STANDARD_ROWMAX];
-
- transform_row(pp, std, in_ct, in_bd, y);
-
- /* Go through each original pixel transforming it and comparing with what
- * libpng did to the same pixel.
- */
- for (x=0; x<w; ++x)
- {
- image_pixel in_pixel, out_pixel;
- unsigned int r, g, b, a;
-
- /* Find out what we think the pixel should be: */
- image_pixel_init(&in_pixel, std, in_ct, in_bd, x, dp->this.palette);
-
- in_pixel.red_sBIT = red_sBIT;
- in_pixel.green_sBIT = green_sBIT;
- in_pixel.blue_sBIT = blue_sBIT;
- in_pixel.alpha_sBIT = alpha_sBIT;
- in_pixel.have_tRNS = have_tRNS;
-
- /* For error detection, below. */
- r = in_pixel.red;
- g = in_pixel.green;
- b = in_pixel.blue;
- a = in_pixel.alpha;
-
- dp->transform_list->mod(dp->transform_list, &in_pixel, pp, dp);
-
- /* Read the output pixel and compare it to what we got, we don't
- * use the error field here, so no need to update sBIT.
- */
- image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette);
-
- /* We don't expect changes to the index here even if the bit depth is
- * changed.
- */
- if (in_ct == PNG_COLOR_TYPE_PALETTE &&
- out_ct == PNG_COLOR_TYPE_PALETTE)
- {
- if (in_pixel.palette_index != out_pixel.palette_index)
- png_error(pp, "unexpected transformed palette index");
- }
-
- /* Check the colours for palette images too - in fact the palette could
- * be separately verified itself in most cases.
- */
- if (in_pixel.red != out_pixel.red)
- transform_range_check(pp, r, g, b, a, in_pixel.red, in_pixel.redf,
- out_pixel.red, sample_depth, in_pixel.rede, "red/gray");
-
- if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 &&
- in_pixel.green != out_pixel.green)
- transform_range_check(pp, r, g, b, a, in_pixel.green,
- in_pixel.greenf, out_pixel.green, sample_depth, in_pixel.greene,
- "green");
-
- if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 &&
- in_pixel.blue != out_pixel.blue)
- transform_range_check(pp, r, g, b, a, in_pixel.blue, in_pixel.bluef,
- out_pixel.blue, sample_depth, in_pixel.bluee, "blue");
-
- if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0 &&
- in_pixel.alpha != out_pixel.alpha)
- transform_range_check(pp, r, g, b, a, in_pixel.alpha,
- in_pixel.alphaf, out_pixel.alpha, sample_depth, in_pixel.alphae,
- "alpha");
- } /* pixel (x) loop */
- } /* row (y) loop */
-
- /* Record that something was actually checked to avoid a false positive. */
- dp->this.ps->validated = 1;
-}
-
-static void
-transform_end(png_structp pp, png_infop pi)
-{
- transform_display *dp = png_get_progressive_ptr(pp);
-
- transform_image_validate(dp, pp, pi, dp->this.ps->image);
-}
-
-/* A single test run. */
-static void
-transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn,
- PNG_CONST image_transform* transform_listIn, PNG_CONST char *name)
-{
- transform_display d;
- context(&pmIn->this, fault);
-
- transform_display_init(&d, pmIn, idIn, transform_listIn);
-
- Try
- {
- png_structp pp;
- png_infop pi;
-
- /* Get a png_struct for writing the image. */
- pp = set_modifier_for_read(d.pm, &pi, d.this.id, name);
-
-# if 0
- /* Logging (debugging only) */
- {
- char buffer[256];
-
- (void)store_message(&d.pm->this, pp, buffer, sizeof buffer, 0,
- "running test");
-
- fprintf(stderr, "%s\n", buffer);
- }
-# endif
-
- /* Introduce the correct read function. */
- if (d.pm->this.progressive)
- {
- /* Share the row function with the standard implementation. */
- png_set_progressive_read_fn(pp, &d, transform_info, progressive_row,
- transform_end);
-
- /* Now feed data into the reader until we reach the end: */
- modifier_progressive_read(d.pm, pp, pi);
- }
- else
- {
- /* modifier_read expects a png_modifier* */
- png_set_read_fn(pp, d.pm, modifier_read);
-
- /* Check the header values: */
- png_read_info(pp, pi);
-
- /* Process the 'info' requirements. Only one image is generated */
- transform_info_imp(&d, pp, pi);
-
- sequential_row(&d.this, pp, pi, NULL, d.this.ps->image);
-
- transform_image_validate(&d, pp, pi, d.this.ps->image);
- }
-
- modifier_reset(d.pm);
- }
-
- Catch(fault)
- modifier_reset((png_modifier*)fault);
-}
-
-/* The transforms: */
-#define ITSTRUCT(name) image_transform_##name
-#define IT(name,prev)\
-static image_transform ITSTRUCT(name) =\
-{\
- #name,\
- 1, /*enable*/\
- &ITSTRUCT(prev), /*list*/\
- 0, /*global_use*/\
- 0, /*local_use*/\
- 0, /*next*/\
- image_transform_png_set_##name##_set,\
- image_transform_png_set_##name##_mod,\
- image_transform_png_set_##name##_add\
-}
-
-/* To save code: */
-static int
-image_transform_default_add(image_transform *this,
- PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
-{
- UNUSED(colour_type)
- UNUSED(bit_depth)
-
- this->next = *that;
- *that = this;
-
- return 1;
-}
-
-/* png_set_palette_to_rgb */
-static void
-image_transform_png_set_palette_to_rgb_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- png_set_palette_to_rgb(pp);
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_palette_to_rgb_mod(PNG_CONST image_transform *this,
- image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
-{
- if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
- image_pixel_convert_PLTE(that, &display->this);
-
- this->next->mod(this->next, that, pp, display);
-}
-
-static int
-image_transform_png_set_palette_to_rgb_add(image_transform *this,
- PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
-{
- UNUSED(bit_depth)
-
- this->next = *that;
- *that = this;
-
- return colour_type == PNG_COLOR_TYPE_PALETTE;
-}
-
-IT(palette_to_rgb, end);
-
-
-/* png_set_tRNS_to_alpha */
-static void
-image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- png_set_tRNS_to_alpha(pp);
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_tRNS_to_alpha_mod(PNG_CONST image_transform *this,
- image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
-{
- /* LIBPNG BUG: this always forces palette images to RGB. */
- if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
- image_pixel_convert_PLTE(that, &display->this);
-
- /* This effectively does an 'expand' only if there is some transparency to
- * covert to an alpha channel.
- */
- if (that->have_tRNS)
- image_pixel_add_alpha(that, &display->this);
-
- /* LIBPNG BUG: otherwise libpng still expands to 8 bits! */
- else
- {
- if (that->bit_depth < 8)
- that->bit_depth =8;
- if (that->sample_depth < 8)
- that->sample_depth = 8;
- }
-
- this->next->mod(this->next, that, pp, display);
-}
-
-static int
-image_transform_png_set_tRNS_to_alpha_add(image_transform *this,
- PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
-{
- UNUSED(bit_depth)
-
- this->next = *that;
- *that = this;
-
- /* We don't know yet whether there will be a tRNS chunk, but we know that
- * this transformation should do nothing if there already is an alpha
- * channel.
- */
- return (colour_type & PNG_COLOR_MASK_ALPHA) == 0;
-}
-
-IT(tRNS_to_alpha,palette_to_rgb);
-
-/* png_set_gray_to_rgb */
-static void
-image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- png_set_gray_to_rgb(pp);
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_gray_to_rgb_mod(PNG_CONST image_transform *this,
- image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
-{
- /* NOTE: we can actually pend the tRNS processing at this point because we
- * can correctly recognize the original pixel value even though we have
- * mapped the one gray channel to the three RGB ones, but in fact libpng
- * doesn't do this, so we don't either.
- */
- if ((that->colour_type & PNG_COLOR_MASK_COLOR) == 0 && that->have_tRNS)
- image_pixel_add_alpha(that, &display->this);
-
- /* Simply expand the bit depth and alter the colour type as required. */
- if (that->colour_type == PNG_COLOR_TYPE_GRAY)
- {
- /* RGB images have a bit depth at least equal to '8' */
- if (that->bit_depth < 8)
- that->sample_depth = that->bit_depth = 8;
-
- /* And just changing the colour type works here because the green and blue
- * channels are being maintained in lock-step with the red/gray:
- */
- that->colour_type = PNG_COLOR_TYPE_RGB;
- }
-
- else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- that->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
-
- this->next->mod(this->next, that, pp, display);
-}
-
-static int
-image_transform_png_set_gray_to_rgb_add(image_transform *this,
- PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
-{
- UNUSED(bit_depth)
-
- this->next = *that;
- *that = this;
-
- return (colour_type & PNG_COLOR_MASK_COLOR) == 0;
-}
-
-IT(gray_to_rgb,tRNS_to_alpha);
-
-/* png_set_expand */
-static void
-image_transform_png_set_expand_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- png_set_expand(pp);
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_expand_mod(PNG_CONST image_transform *this,
- image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
-{
- /* The general expand case depends on what the colour type is: */
- if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
- image_pixel_convert_PLTE(that, &display->this);
- else if (that->bit_depth < 8) /* grayscale */
- that->sample_depth = that->bit_depth = 8;
-
- if (that->have_tRNS)
- image_pixel_add_alpha(that, &display->this);
-
- this->next->mod(this->next, that, pp, display);
-}
-
-static int
-image_transform_png_set_expand_add(image_transform *this,
- PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
-{
- UNUSED(bit_depth)
-
- this->next = *that;
- *that = this;
-
- /* 'expand' should do nothing for RGBA or GA input - no tRNS and the bit
- * depth is at least 8 already.
- */
- return (colour_type & PNG_COLOR_MASK_ALPHA) == 0;
-}
-
-IT(expand,gray_to_rgb);
-
-/* png_set_expand_gray_1_2_4_to_8
- * LIBPNG BUG: this just does an 'expand'
- */
-static void
-image_transform_png_set_expand_gray_1_2_4_to_8_set(
- PNG_CONST image_transform *this, transform_display *that, png_structp pp,
- png_infop pi)
-{
- png_set_expand_gray_1_2_4_to_8(pp);
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_expand_gray_1_2_4_to_8_mod(
- PNG_CONST image_transform *this, image_pixel *that, png_structp pp,
- PNG_CONST transform_display *display)
-{
- image_transform_png_set_expand_mod(this, that, pp, display);
-}
-
-static int
-image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this,
- PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
-{
- return image_transform_png_set_expand_add(this, that, colour_type,
- bit_depth);
-}
-
-IT(expand_gray_1_2_4_to_8, expand);
-
-/* png_set_strip_16 */
-static void
-image_transform_png_set_strip_16_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- png_set_strip_16(pp);
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this,
- image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
-{
- if (that->bit_depth == 16)
- {
- that->sample_depth = that->bit_depth = 8;
- if (that->red_sBIT > 8) that->red_sBIT = 8;
- if (that->green_sBIT > 8) that->green_sBIT = 8;
- if (that->blue_sBIT > 8) that->blue_sBIT = 8;
- if (that->alpha_sBIT > 8) that->alpha_sBIT = 8;
-
-# ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
- /* The strip 16 algoirithm drops the low 8 bits rather than calculating
- * 1/257, so we need to adjust the permitted errors appropriately:
- */
- {
- PNG_CONST double d = (255-128.5)/65535;
- that->rede += d;
- that->greene += d;
- that->bluee += d;
- that->alphae += d;
- }
-# endif
- }
-
- this->next->mod(this->next, that, pp, display);
-}
-
-static int
-image_transform_png_set_strip_16_add(image_transform *this,
- PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
-{
- UNUSED(colour_type)
-
- this->next = *that;
- *that = this;
-
- return bit_depth > 8;
-}
-
-IT(strip_16, expand_gray_1_2_4_to_8);
-
-/* png_set_strip_alpha */
-static void
-image_transform_png_set_strip_alpha_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- png_set_strip_alpha(pp);
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_strip_alpha_mod(PNG_CONST image_transform *this,
- image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
-{
- if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- that->colour_type = PNG_COLOR_TYPE_GRAY;
- else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
- that->colour_type = PNG_COLOR_TYPE_RGB;
-
- that->have_tRNS = 0;
- that->alphaf = 1;
- that->alphae = 0;
-
- this->next->mod(this->next, that, pp, display);
-}
-
-static int
-image_transform_png_set_strip_alpha_add(image_transform *this,
- PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
-{
- UNUSED(bit_depth)
-
- this->next = *that;
- *that = this;
-
- return (colour_type & PNG_COLOR_MASK_ALPHA) != 0;
-}
-
-IT(strip_alpha,strip_16);
-
-/* png_set_rgb_to_gray(png_structp, int err_action, double red, double green)
- * png_set_rgb_to_gray_fixed(png_structp, int err_action, png_fixed_point red,
- * png_fixed_point green)
- * png_get_rgb_to_gray_status
- *
- * At present the APIs are simply tested using the 16.16 fixed point conversion
- * values known to be used inside libpng:
- *
- * red: 6968
- * green: 23434
- * blue: 2366
- *
- * NOTE: this currently ignores the gamma because no gamma is being set, the
- * tests on gamma need to happen in the gamma test set.
- */
-static void
-image_transform_png_set_rgb_to_gray_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- PNG_CONST int error_action = 1; /* no error, no defines in png.h */
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
- png_set_rgb_to_gray(pp, error_action, -1, -1);
-# else
- png_set_rgb_to_gray_fixed(pp, error_action, -1, -1);
-# endif
-
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
- image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
-{
- if ((that->colour_type & PNG_COLOR_MASK_COLOR) != 0)
- {
- if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
- image_pixel_convert_PLTE(that, &display->this);
-
- /* Image now has RGB channels... */
- that->bluef = that->greenf = that->redf = (that->redf * 6968 +
- that->greenf * 23434 + that->bluef * 2366) / 32768;
- that->bluee = that->greene = that->rede = (that->rede * 6968 +
- that->greene * 23434 + that->bluee * 2366) / 32768 *
- (1 + DBL_EPSILON * 6);
-
- /* The sBIT is the minium of the three colour channel sBITs. */
- if (that->red_sBIT > that->green_sBIT)
- that->red_sBIT = that->green_sBIT;
- if (that->red_sBIT > that->blue_sBIT)
- that->red_sBIT = that->blue_sBIT;
- that->blue_sBIT = that->green_sBIT = that->red_sBIT;
-
- /* And zap the colour bit in the type: */
- if (that->colour_type == PNG_COLOR_TYPE_RGB)
- that->colour_type = PNG_COLOR_TYPE_GRAY;
- else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
- that->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA;
- }
-
- this->next->mod(this->next, that, pp, display);
-}
-
-static int
-image_transform_png_set_rgb_to_gray_add(image_transform *this,
- PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
-{
- UNUSED(bit_depth)
-
- this->next = *that;
- *that = this;
-
- return (colour_type & PNG_COLOR_MASK_COLOR) != 0;
-}
-
-IT(rgb_to_gray,strip_alpha);
-
-/* png_set_background(png_structp, png_const_color_16p background_color,
- * int background_gamma_code, int need_expand, double background_gamma)
- * png_set_background_fixed(png_structp, png_const_color_16p background_color,
- * int background_gamma_code, int need_expand,
- * png_fixed_point background_gamma)
- *
- * As with rgb_to_gray this ignores the gamma.
-*/
-static void
-image_transform_png_set_background_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- png_color_16 back;
-
- /* Since we don't know the output bit depth at this point we must use the
- * input values and ask libpng to expand the chunk as required.
- */
- back.index = 255; /* Should not be used */
- back.gray = back.blue = back.green = back.red =
- (png_uint_16)((1U << that->this.bit_depth) >> 1);
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
- png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1, 0);
-# else
- png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1, 0);
-# endif
-
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_background_mod(PNG_CONST image_transform *this,
- image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
-{
- /* Check for tRNS first: */
- if (that->have_tRNS && that->colour_type != PNG_COLOR_TYPE_PALETTE)
- image_pixel_add_alpha(that, &display->this);
-
- /* This is only necessary if the alpha value is less than 1. */
- if (that->alphaf < 1)
- {
- /* Repeat the calculation above and scale the result: */
- unsigned int tmp = (1U << display->this.bit_depth);
- double component = (tmp >> 1)/(double)(tmp-1);
-
- /* Now we do the background calculation without any gamma correction. */
- if (that->alphaf <= 0)
- {
- that->bluef = that->greenf = that->redf = component;
- that->bluee = that->greene = that->rede = component * DBL_EPSILON;
- that->blue_sBIT = that->green_sBIT = that->red_sBIT = that->bit_depth;
- }
-
- else
- {
- component *= 1-that->alphaf;
- that->redf = that->redf * that->alphaf + component;
- that->rede = that->rede * that->alphaf + that->redf * 3 * DBL_EPSILON;
- that->greenf = that->greenf * that->alphaf + component;
- that->greene = that->greene * that->alphaf + that->greenf * 3 *
- DBL_EPSILON;
- that->bluef = that->bluef * that->alphaf + component;
- that->bluee = that->bluee * that->alphaf + that->bluef * 3 *
- DBL_EPSILON;
- }
-
- /* Remove the alpha type and set the alpha. */
- that->alphaf = 1;
- that->alphae = 0;
-
- if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
- that->colour_type = PNG_COLOR_TYPE_RGB;
- else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- that->colour_type = PNG_COLOR_TYPE_GRAY;
- }
-
- this->next->mod(this->next, that, pp, display);
-}
-
-#define image_transform_png_set_background_add image_transform_default_add
-
-IT(background,rgb_to_gray);
-
-static image_transform *PNG_CONST image_transform_first = &ITSTRUCT(background);
-
-static void
-transform_enable(PNG_CONST char *name)
-{
- /* Everything starts out enabled, so if we see an 'enable' disabled
- * everything else the first time round.
- */
- static int all_disabled = 0;
- int found_it = 0;
- image_transform *list = image_transform_first;
-
- while (list != &image_transform_end)
- {
- if (strcmp(list->name, name) == 0)
- {
- list->enable = 1;
- found_it = 1;
- }
- else if (!all_disabled)
- list->enable = 0;
-
- list = list->list;
- }
-
- all_disabled = 1;
-
- if (!found_it)
- {
- fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n",
- name);
- exit(1);
- }
-}
-
-static void
-transform_disable(PNG_CONST char *name)
-{
- image_transform *list = image_transform_first;
-
- while (list != &image_transform_end)
- {
- if (strcmp(list->name, name) == 0)
- {
- list->enable = 0;
- return;
- }
-
- list = list->list;
- }
-
- fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n",
- name);
- exit(1);
-}
-
-static void
-image_transform_reset_count(void)
-{
- image_transform *next = image_transform_first;
- int count = 0;
-
- while (next != &image_transform_end)
- {
- next->local_use = 0;
- next->next = 0;
- next = next->list;
- ++count;
- }
-
- /* This can only happen if we every have more than 32 transforms (excluding
- * the end) in the list.
- */
- if (count > 32) abort();
-}
-
-static int
-image_transform_test_counter(png_uint_32 counter, unsigned int max)
-{
- /* Test the list to see if there is any point contining, given a current
- * counter and a 'max' value.
- */
- image_transform *next = image_transform_first;
-
- while (next != &image_transform_end)
- {
- /* For max 0 or 1 continue until the counter overflows: */
- counter >>= 1;
-
- /* Continue if any entry hasn't reacked the max. */
- if (max > 1 && next->local_use < max)
- return 1;
- next = next->list;
- }
-
- return max <= 1 && counter == 0;
-}
-
-static png_uint_32
-image_transform_add(PNG_CONST image_transform **this, unsigned int max,
- png_uint_32 counter, char *name, size_t sizeof_name, size_t *pos,
- png_byte colour_type, png_byte bit_depth)
-{
- for (;;) /* until we manage to add something */
- {
- png_uint_32 mask;
- image_transform *list;
-
- /* Find the next counter value, if the counter is zero this is the start
- * of the list. This routine always returns the current counter (not the
- * next) so it returns 0 at the end and expects 0 at the beginning.
- */
- if (counter == 0) /* first time */
- {
- image_transform_reset_count();
- if (max <= 1)
- counter = 1;
- else
- counter = random_32();
- }
- else /* advance the counter */
- {
- switch (max)
- {
- case 0: ++counter; break;
- case 1: counter <<= 1; break;
- default: counter = random_32(); break;
- }
- }
-
- /* Now add all these items, if possible */
- *this = &image_transform_end;
- list = image_transform_first;
- mask = 1;
-
- /* Go through the whole list adding anything that the counter selects: */
- while (list != &image_transform_end)
- {
- if ((counter & mask) != 0 && list->enable &&
- (max == 0 || list->local_use < max))
- {
- /* Candidate to add: */
- if (list->add(list, this, colour_type, bit_depth) || max == 0)
- {
- /* Added, so add to the name too. */
- *pos = safecat(name, sizeof_name, *pos, " +");
- *pos = safecat(name, sizeof_name, *pos, list->name);
- }
-
- else
- {
- /* Not useful and max>0, so remvoe it from *this: */
- *this = list->next;
- list->next = 0;
-
- /* And, since we know it isn't useful, stop it being added again
- * in this run:
- */
- list->local_use = max;
- }
- }
-
- mask <<= 1;
- list = list->list;
- }
-
- /* Now if anything was added we have something to do. */
- if (*this != &image_transform_end)
- return counter;
-
- /* Nothing added, but was there anything in there to add? */
- if (!image_transform_test_counter(counter, max))
- return 0;
- }
-}
-
-#ifdef THIS_IS_THE_PROFORMA
-static void
-image_transform_png_set_@_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
-{
- png_set_@(pp);
- this->next->set(this->next, that, pp, pi);
-}
-
-static void
-image_transform_png_set_@_mod(PNG_CONST image_transform *this,
- image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
-{
- this->next->mod(this->next, that, pp, display);
-}
-
-static int
-image_transform_png_set_@_add(image_transform *this,
- PNG_CONST image_transform **that, char *name, size_t sizeof_name,
- size_t *pos, png_byte colour_type, png_byte bit_depth)
-{
- this->next = *that;
- *that = this;
-
- *pos = safecat(name, sizeof_name, *pos, " +@");
-
- return 1;
-}
-
-IT(@);
-#endif
-
-/* png_set_quantize(png_structp, png_colorp palette, int num_palette,
- * int maximum_colors, png_const_uint_16p histogram, int full_quantize)
- *
- * Very difficult to validate this!
- */
-/*NOTE: TBD NYI */
-
-/* The data layout transforms are handled by swapping our own channel data,
- * necessarily these need to happen at the end of the transform list because the
- * semantic of the channels changes after these are executed. Some of these,
- * like set_shift and set_packing, can't be done at present because they change
- * the layout of the data at the sub-sample level so sample() won't get the
- * right answer.
- */
-/* png_set_invert_alpha */
-/*NOTE: TBD NYI */
-
-/* png_set_bgr */
-/*NOTE: TBD NYI */
-
-/* png_set_swap_alpha */
-/*NOTE: TBD NYI */
-
-/* png_set_swap */
-/*NOTE: TBD NYI */
-
-/* png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); */
-/*NOTE: TBD NYI */
-
-/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */
-/*NOTE: TBD NYI */
-
-/* png_set_packing */
-/*NOTE: TBD NYI */
-
-/* png_set_packswap */
-/*NOTE: TBD NYI */
-
-/* png_set_invert_mono */
-/*NOTE: TBD NYI */
-
-/* png_set_shift(png_structp, png_const_color_8p true_bits) */
-/*NOTE: TBD NYI */
-
-static int
-test_transform(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
- int bdlo, int PNG_CONST bdhi, png_uint_32 max)
-{
- for (; bdlo <= bdhi; ++bdlo)
- {
- PNG_CONST png_byte bit_depth = DEPTH(bdlo);
- png_uint_32 counter = 0;
- size_t base_pos;
- char name[64];
-
- base_pos = safecat(name, sizeof name, 0, "transform:");
-
- for (;;)
- {
- size_t pos = base_pos;
- PNG_CONST image_transform *list = 0;
-
- counter = image_transform_add(&list, max, counter, name, sizeof name,
- &pos, colour_type, bit_depth);
-
- if (counter == 0)
- break;
-
- /* The command line can change this to checking interlaced images. */
- transform_test(pm, FILEID(colour_type, bit_depth, pm->interlace_type,
- 0, 0, 0), list, name);
-
- if (fail(pm))
- return 0;
- }
- }
-
- return 1; /* keep going */
-}
-
-static void
-perform_transform_test(png_modifier *pm)
-{
- /* Test each colour type over the valid range of bit depths (expressed as
- * log2(bit_depth) in turn, stop as soon as any error is detected.
- */
- if (!test_transform(pm, 0, 0, READ_BDHI, 1))
- return;
-
- if (!test_transform(pm, 2, 3, READ_BDHI, 1))
- return;
-
- if (!test_transform(pm, 3, 0, 3, 1))
- return;
-
- if (!test_transform(pm, 4, 3, READ_BDHI, 1))
- return;
-
- if (!test_transform(pm, 6, 3, READ_BDHI, 1))
- return;
-}
-
-
-/********************************* GAMMA TESTS ********************************/
-/* Gamma test images. */
-typedef struct gamma_modification
-{
- png_modification this;
- png_fixed_point gamma;
-} gamma_modification;
-
-static int
-gamma_modify(png_modifier *pm, png_modification *me, int add)
-{
- UNUSED(add)
- /* This simply dumps the given gamma value into the buffer. */
- png_save_uint_32(pm->buffer, 4);
- png_save_uint_32(pm->buffer+4, CHUNK_gAMA);
- png_save_uint_32(pm->buffer+8, ((gamma_modification*)me)->gamma);
- return 1;
-}
-
-static void
-gamma_modification_init(gamma_modification *me, png_modifier *pm, double gammad)
-{
- double g;
-
- modification_init(&me->this);
- me->this.chunk = CHUNK_gAMA;
- me->this.modify_fn = gamma_modify;
- me->this.add = CHUNK_PLTE;
- g = floor(gammad * 100000 + .5);
- me->gamma = (png_fixed_point)g;
- me->this.next = pm->modifications;
- pm->modifications = &me->this;
-}
-
-typedef struct srgb_modification
-{
- png_modification this;
- png_byte intent;
-} srgb_modification;
-
-static int
-srgb_modify(png_modifier *pm, png_modification *me, int add)
-{
- UNUSED(add)
- /* As above, ignore add and just make a new chunk */
- png_save_uint_32(pm->buffer, 1);
- png_save_uint_32(pm->buffer+4, CHUNK_sRGB);
- pm->buffer[8] = ((srgb_modification*)me)->intent;
- return 1;
-}
-
-static void
-srgb_modification_init(srgb_modification *me, png_modifier *pm, png_byte intent)
-{
- modification_init(&me->this);
- me->this.chunk = CHUNK_sBIT;
-
- if (intent <= 3) /* if valid, else *delete* sRGB chunks */
- {
- me->this.modify_fn = srgb_modify;
- me->this.add = CHUNK_PLTE;
- me->intent = intent;
- }
-
- else
- {
- me->this.modify_fn = 0;
- me->this.add = 0;
- me->intent = 0;
- }
-
- me->this.next = pm->modifications;
- pm->modifications = &me->this;
-}
-
-typedef struct sbit_modification
-{
- png_modification this;
- png_byte sbit;
-} sbit_modification;
-
-static int
-sbit_modify(png_modifier *pm, png_modification *me, int add)
-{
- png_byte sbit = ((sbit_modification*)me)->sbit;
- if (pm->bit_depth > sbit)
- {
- int cb = 0;
- switch (pm->colour_type)
- {
- case 0:
- cb = 1;
- break;
-
- case 2:
- case 3:
- cb = 3;
- break;
-
- case 4:
- cb = 2;
- break;
-
- case 6:
- cb = 4;
- break;
-
- default:
- png_error(pm->this.pread,
- "unexpected colour type in sBIT modification");
- }
-
- png_save_uint_32(pm->buffer, cb);
- png_save_uint_32(pm->buffer+4, CHUNK_sBIT);
-
- while (cb > 0)
- (pm->buffer+8)[--cb] = sbit;
-
- return 1;
- }
- else if (!add)
- {
- /* Remove the sBIT chunk */
- pm->buffer_count = pm->buffer_position = 0;
- return 1;
- }
- else
- return 0; /* do nothing */
-}
-
-static void
-sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit)
-{
- modification_init(&me->this);
- me->this.chunk = CHUNK_sBIT;
- me->this.modify_fn = sbit_modify;
- me->this.add = CHUNK_PLTE;
- me->sbit = sbit;
- me->this.next = pm->modifications;
- pm->modifications = &me->this;
-}
-
-/* Reader callbacks and implementations, where they differ from the standard
- * ones.
- */
-typedef struct gamma_display
-{
- standard_display this;
-
- /* Parameters */
- png_modifier* pm;
- double file_gamma;
- double screen_gamma;
- png_byte sbit;
- int threshold_test;
- PNG_CONST char* name;
- int speed;
- int use_input_precision;
- int strip16;
-
- /* Local variables */
- double maxerrout;
- double maxerrpc;
- double maxerrabs;
-} gamma_display;
-
-static void
-gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id,
- double file_gamma, double screen_gamma, png_byte sbit, int threshold_test,
- int speed, int use_input_precision, int strip16)
-{
- /* Standard fields */
- standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/);
-
- /* Parameter fields */
- dp->pm = pm;
- dp->file_gamma = file_gamma;
- dp->screen_gamma = screen_gamma;
- dp->sbit = sbit;
- dp->threshold_test = threshold_test;
- dp->speed = speed;
- dp->use_input_precision = use_input_precision;
- dp->strip16 = strip16;
-
- /* Local variable fields */
- dp->maxerrout = dp->maxerrpc = dp->maxerrabs = 0;
-}
-
-static void
-gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi)
-{
- /* Reuse the standard stuff as appropriate. */
- standard_info_part1(&dp->this, pp, pi);
-
- /* If requested strip 16 to 8 bits - this is handled automagically below
- * because the output bit depth is read from the library. Note that there
- * are interactions with sBIT but, internally, libpng makes sbit at most
- * PNG_MAX_GAMMA_8 when doing the following.
- */
- if (dp->strip16)
-# ifdef PNG_READ_16_TO_8_SUPPORTED
- png_set_strip_16(pp);
-# else
- png_error(pp, "strip16 (16 to 8 bit conversion) not supported");
-# endif
-
- png_read_update_info(pp, pi);
-
- /* Now we may get a different cbRow: */
- standard_info_part2(&dp->this, pp, pi, 1 /*images*/);
-}
-
-static void
-gamma_info(png_structp pp, png_infop pi)
-{
- gamma_info_imp(png_get_progressive_ptr(pp), pp, pi);
-}
-
-static void
-gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi,
- png_const_bytep pRow)
-{
- /* Get some constants derived from the input and output file formats: */
- PNG_CONST png_byte sbit = dp->sbit;
- PNG_CONST double file_gamma = dp->file_gamma;
- PNG_CONST double screen_gamma = dp->screen_gamma;
- PNG_CONST int use_input_precision = dp->use_input_precision;
- PNG_CONST int speed = dp->speed;
- PNG_CONST png_byte in_ct = dp->this.colour_type;
- PNG_CONST png_byte in_bd = dp->this.bit_depth;
- PNG_CONST png_uint_32 w = dp->this.w;
- PNG_CONST png_uint_32 h = dp->this.h;
- PNG_CONST size_t cbRow = dp->this.cbRow;
- PNG_CONST png_byte out_ct = png_get_color_type(pp, pi);
- PNG_CONST png_byte out_bd = png_get_bit_depth(pp, pi);
- PNG_CONST unsigned int outmax = (1U<<out_bd)-1;
- PNG_CONST double maxabs = abserr(dp->pm, out_bd);
- PNG_CONST double maxout = outerr(dp->pm, out_bd);
- PNG_CONST double maxpc = pcerr(dp->pm, out_bd);
-
- /* There are three sources of error, firstly the quantization in the
- * file encoding, determined by sbit and/or the file depth, secondly
- * the output (screen) gamma and thirdly the output file encoding.
- *
- * Since this API receives the screen and file gamma in double
- * precision it is possible to calculate an exact answer given an input
- * pixel value. Therefore we assume that the *input* value is exact -
- * sample/maxsample - calculate the corresponding gamma corrected
- * output to the limits of double precision arithmetic and compare with
- * what libpng returns.
- *
- * Since the library must quantize the output to 8 or 16 bits there is
- * a fundamental limit on the accuracy of the output of +/-.5 - this
- * quantization limit is included in addition to the other limits
- * specified by the paramaters to the API. (Effectively, add .5
- * everywhere.)
- *
- * The behavior of the 'sbit' paramter is defined by section 12.5
- * (sample depth scaling) of the PNG spec. That section forces the
- * decoder to assume that the PNG values have been scaled if sBIT is
- * present:
- *
- * png-sample = floor( input-sample * (max-out/max-in) + .5);
- *
- * This means that only a subset of the possible PNG values should
- * appear in the input. However, the spec allows the encoder to use a
- * variety of approximations to the above and doesn't require any
- * restriction of the values produced.
- *
- * Nevertheless the spec requires that the upper 'sBIT' bits of the
- * value stored in a PNG file be the original sample bits.
- * Consequently the code below simply scales the top sbit bits by
- * (1<<sbit)-1 to obtain an original sample value.
- *
- * Because there is limited precision in the input it is arguable that
- * an acceptable result is any valid result from input-.5 to input+.5.
- * The basic tests below do not do this, however if
- * 'use_input_precision' is set a subsequent test is performed below.
- */
- PNG_CONST int processing = (fabs(screen_gamma*file_gamma-1) >=
- PNG_GAMMA_THRESHOLD && !dp->threshold_test && !speed && in_ct != 3) ||
- in_bd != out_bd;
-
- PNG_CONST unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U;
-
- PNG_CONST double gamma_correction = 1/(file_gamma*screen_gamma);/* Overall */
-
- double maxerrout = 0, maxerrabs = 0, maxerrpc = 0;
- png_uint_32 y;
-
- for (y=0; y<h; ++y, pRow += cbRow)
- {
- unsigned int s, x;
- png_byte std[STANDARD_ROWMAX];
-
- transform_row(pp, std, in_ct, in_bd, y);
-
- if (processing)
- {
- for (x=0; x<w; ++x) for (s=0; s<samples_per_pixel; ++s)
- {
- /* Input sample values: */
- PNG_CONST unsigned int
- id = sample(std, in_ct, in_bd, x, s);
-
- PNG_CONST unsigned int
- od = sample(pRow, out_ct, out_bd, x, s);
-
- PNG_CONST unsigned int
- isbit = id >> (in_bd-sbit);
-
- double i, input_sample, encoded_sample, output;
- double encoded_error, error;
- double es_lo, es_hi;
-
- /* First check on the 'perfect' result obtained from the
- * digitized input value, id, and compare this against the
- * actual digitized result, 'od'. 'i' is the input result
- * in the range 0..1:
- *
- * NOTE: sBIT should be taken into account here but isn't,
- * as described above.
- */
- i = isbit; i /= (1U<<sbit)-1;
-
- /* Then get the gamma corrected version of 'i' and compare
- * to 'od', any error less than .5 is insignificant - just
- * quantization of the output value to the nearest digital
- * value (nevertheless the error is still recorded - it's
- * interesting ;-)
- */
- encoded_sample = pow(i, gamma_correction) * outmax;
- encoded_error = fabs(od-encoded_sample);
-
- if (encoded_error > maxerrout)
- maxerrout = encoded_error;
-
- if (encoded_error < .5+maxout)
- continue;
-
- /* There may be an error, so calculate the actual sample
- * values - unencoded light intensity values. Note that
- * in practice these are not unencoded because they
- * include a 'viewing correction' to decrease or
- * (normally) increase the perceptual contrast of the
- * image. There's nothing we can do about this - we don't
- * know what it is - so assume the unencoded value is
- * perceptually linear.
- */
- input_sample = pow(i, 1/file_gamma); /* In range 0..1 */
- output = od;
- output /= outmax;
- output = pow(output, screen_gamma);
-
- /* Now we have the numbers for real errors, both absolute
- * values as as a percentage of the correct value (output):
- */
- error = fabs(input_sample-output);
-
- if (error > maxerrabs)
- maxerrabs = error;
-
- /* The following is an attempt to ignore the tendency of
- * quantization to dominate the percentage errors for low
- * output sample values:
- */
- if (input_sample*maxpc > .5+maxabs)
- {
- double percentage_error = error/input_sample;
- if (percentage_error > maxerrpc) maxerrpc = percentage_error;
- }
-
- /* Now calculate the digitization limits for
- * 'encoded_sample' using the 'max' values. Note that
- * maxout is in the encoded space but maxpc and maxabs are
- * in linear light space.
- *
- * First find the maximum error in linear light space,
- * range 0..1:
- */
- {
- double tmp = input_sample * maxpc;
- if (tmp < maxabs) tmp = maxabs;
-
- /* Low bound - the minimum of the three: */
- es_lo = encoded_sample - maxout;
-
- if (es_lo > 0 && input_sample-tmp > 0)
- {
- double low_value = outmax * pow(input_sample-tmp,
- 1/screen_gamma);
- if (low_value < es_lo) es_lo = low_value;
- }
-
- else
- es_lo = 0;
-
- es_hi = encoded_sample + maxout;
-
- if (es_hi < outmax && input_sample+tmp < 1)
- {
- double high_value = outmax * pow(input_sample+tmp,
- 1/screen_gamma);
- if (high_value > es_hi) es_hi = high_value;
- }
-
- else
- es_hi = outmax;
- }
-
- /* The primary test is that the final encoded value
- * returned by the library should be between the two limits
- * (inclusive) that were calculated above. At this point
- * quantization of the output must be taken into account.
- */
- if (od+.5 < es_lo || od-.5 > es_hi)
- {
- /* There has been an error in processing. */
- double is_lo, is_hi;
-
- if (use_input_precision)
- {
- /* Ok, something is wrong - this actually happens in
- * current libpng sbit processing. Assume that the
- * input value (id, adjusted for sbit) can be
- * anywhere between value-.5 and value+.5 - quite a
- * large range if sbit is low.
- */
- double tmp = (isbit - .5)/((1U<<sbit)-1);
-
- if (tmp > 0)
- {
- is_lo = outmax * pow(tmp, gamma_correction) - maxout;
- if (is_lo < 0) is_lo = 0;
- }
-
- else
- is_lo = 0;
-
- tmp = (isbit + .5)/((1U<<sbit)-1);
-
- if (tmp < 1)
- {
- is_hi = outmax * pow(tmp, gamma_correction) + maxout;
- if (is_hi > outmax) is_hi = outmax;
- }
-
- else
- is_hi = outmax;
-
- if (!(od+.5 < is_lo || od-.5 > is_hi))
- continue;
- }
- else
- is_lo = es_lo, is_hi = es_hi;
-
- {
- char msg[256];
-
- sprintf(msg,
- "error: %.3f; %u{%u;%u} -> %u not %.2f (%.1f-%.1f)",
- od-encoded_sample, id, sbit, isbit, od,
- encoded_sample, is_lo, is_hi);
-
- png_warning(pp, msg);
- }
- }
- }
- }
-
- else if (!speed && memcmp(std, pRow, cbRow) != 0)
- {
- char msg[64];
-
- /* No transform is expected on the threshold tests. */
- sprintf(msg, "gamma: below threshold row %d changed", y);
-
- png_error(pp, msg);
- }
- } /* row (y) loop */
-
- dp->maxerrout = maxerrout;
- dp->maxerrabs = maxerrabs;
- dp->maxerrpc = maxerrpc;
- dp->this.ps->validated = 1;
-}
-
-static void
-gamma_end(png_structp pp, png_infop pi)
-{
- gamma_display *dp = png_get_progressive_ptr(pp);
-
- gamma_image_validate(dp, pp, pi, dp->this.ps->image);
-}
-
-/* A single test run checking a gamma transformation.
- *
- * maxabs: maximum absolute error as a fraction
- * maxout: maximum output error in the output units
- * maxpc: maximum percentage error (as a percentage)
- */
-static void
-gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn,
- PNG_CONST png_byte bit_depthIn, PNG_CONST int interlace_typeIn,
- PNG_CONST double file_gammaIn, PNG_CONST double screen_gammaIn,
- PNG_CONST png_byte sbitIn, PNG_CONST int threshold_testIn,
- PNG_CONST char *name, PNG_CONST int speedIn,
- PNG_CONST int use_input_precisionIn, PNG_CONST int strip16In)
-{
- gamma_display d;
- context(&pmIn->this, fault);
-
- gamma_display_init(&d, pmIn, FILEID(colour_typeIn, bit_depthIn,
- interlace_typeIn, 0, 0, 0), file_gammaIn, screen_gammaIn, sbitIn,
- threshold_testIn, speedIn, use_input_precisionIn, strip16In);
-
- Try
- {
- png_structp pp;
- png_infop pi;
- gamma_modification gamma_mod;
- srgb_modification srgb_mod;
- sbit_modification sbit_mod;
-
- /* Make an appropriate modifier to set the PNG file gamma to the
- * given gamma value and the sBIT chunk to the given precision.
- */
- d.pm->modifications = NULL;
- gamma_modification_init(&gamma_mod, d.pm, d.file_gamma);
- srgb_modification_init(&srgb_mod, d.pm, 127 /*delete*/);
- sbit_modification_init(&sbit_mod, d.pm, d.sbit);
-
- modification_reset(d.pm->modifications);
-
- /* Get a png_struct for writing the image. */
- pp = set_modifier_for_read(d.pm, &pi, d.this.id, name);
-
- /* Set up gamma processing. */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
- png_set_gamma(pp, d.screen_gamma, d.file_gamma);
-#else
- {
- png_fixed_point s = floor(d.screen_gamma*100000+.5);
- png_fixed_point f = floor(d.file_gamma*100000+.5);
- png_set_gamma_fixed(pp, s, f);
- }
-#endif
-
- /* Introduce the correct read function. */
- if (d.pm->this.progressive)
- {
- /* Share the row function with the standard implementation. */
- png_set_progressive_read_fn(pp, &d, gamma_info, progressive_row,
- gamma_end);
-
- /* Now feed data into the reader until we reach the end: */
- modifier_progressive_read(d.pm, pp, pi);
- }
- else
- {
- /* modifier_read expects a png_modifier* */
- png_set_read_fn(pp, d.pm, modifier_read);
-
- /* Check the header values: */
- png_read_info(pp, pi);
-
- /* Process the 'info' requirements. Only one image is generated */
- gamma_info_imp(&d, pp, pi);
-
- sequential_row(&d.this, pp, pi, NULL, d.this.ps->image);
-
- gamma_image_validate(&d, pp, pi, d.this.ps->image);
- }
-
- modifier_reset(d.pm);
-
- if (d.pm->log && !d.threshold_test && !d.speed)
- fprintf(stderr, "%d bit %s %s: max error %f (%.2g, %2g%%)\n",
- d.this.bit_depth, colour_types[d.this.colour_type], d.name,
- d.maxerrout, d.maxerrabs, 100*d.maxerrpc);
-
- /* Log the summary values too. */
- if (d.this.colour_type == 0 || d.this.colour_type == 4)
- {
- switch (d.this.bit_depth)
- {
- case 1:
- break;
-
- case 2:
- if (d.maxerrout > d.pm->error_gray_2)
- d.pm->error_gray_2 = d.maxerrout;
-
- break;
-
- case 4:
- if (d.maxerrout > d.pm->error_gray_4)
- d.pm->error_gray_4 = d.maxerrout;
-
- break;
-
- case 8:
- if (d.maxerrout > d.pm->error_gray_8)
- d.pm->error_gray_8 = d.maxerrout;
-
- break;
-
- case 16:
- if (d.maxerrout > d.pm->error_gray_16)
- d.pm->error_gray_16 = d.maxerrout;
-
- break;
-
- default:
- png_error(pp, "bad bit depth (internal: 1)");
- }
- }
-
- else if (d.this.colour_type == 2 || d.this.colour_type == 6)
- {
- switch (d.this.bit_depth)
- {
- case 8:
-
- if (d.maxerrout > d.pm->error_color_8)
- d.pm->error_color_8 = d.maxerrout;
-
- break;
-
- case 16:
-
- if (d.maxerrout > d.pm->error_color_16)
- d.pm->error_color_16 = d.maxerrout;
-
- break;
-
- default:
- png_error(pp, "bad bit depth (internal: 2)");
- }
- }
- }
-
- Catch(fault)
- modifier_reset((png_modifier*)fault);
-}
-
-static void gamma_threshold_test(png_modifier *pm, png_byte colour_type,
- png_byte bit_depth, int interlace_type, double file_gamma,
- double screen_gamma)
-{
- size_t pos = 0;
- char name[64];
- pos = safecat(name, sizeof name, pos, "threshold ");
- pos = safecatd(name, sizeof name, pos, file_gamma, 3);
- pos = safecat(name, sizeof name, pos, "/");
- pos = safecatd(name, sizeof name, pos, screen_gamma, 3);
-
- (void)gamma_test(pm, colour_type, bit_depth, interlace_type, file_gamma,
- screen_gamma, bit_depth, 1, name, 0 /*speed*/, 0 /*no input precision*/,
- 0 /*no strip16*/);
-}
-
-static void
-perform_gamma_threshold_tests(png_modifier *pm)
-{
- png_byte colour_type = 0;
- png_byte bit_depth = 0;
-
- while (next_format(&colour_type, &bit_depth))
- {
- double test_gamma = 1.0;
- while (test_gamma >= .4)
- {
- /* There's little point testing the interlacing vs non-interlacing,
- * but this can be set from the command line.
- */
- gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type,
- test_gamma, 1/test_gamma);
- test_gamma *= .95;
- }
-
- /* And a special test for sRGB */
- gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type,
- .45455, 2.2);
-
- if (fail(pm))
- return;
- }
-}
-
-static void gamma_transform_test(png_modifier *pm,
- PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth,
- PNG_CONST int interlace_type, PNG_CONST double file_gamma,
- PNG_CONST double screen_gamma, PNG_CONST png_byte sbit, PNG_CONST int speed,
- PNG_CONST int use_input_precision, PNG_CONST int strip16)
-{
- size_t pos = 0;
- char name[64];
-
- if (sbit != bit_depth)
- {
- pos = safecat(name, sizeof name, pos, "sbit(");
- pos = safecatn(name, sizeof name, pos, sbit);
- pos = safecat(name, sizeof name, pos, ") ");
- }
-
- else
- pos = safecat(name, sizeof name, pos, "gamma ");
-
- if (strip16)
- pos = safecat(name, sizeof name, pos, "16to8 ");
-
- pos = safecatd(name, sizeof name, pos, file_gamma, 3);
- pos = safecat(name, sizeof name, pos, "->");
- pos = safecatd(name, sizeof name, pos, screen_gamma, 3);
-
- gamma_test(pm, colour_type, bit_depth, interlace_type, file_gamma,
- screen_gamma, sbit, 0, name, speed, use_input_precision, strip16);
-}
-
-static void perform_gamma_transform_tests(png_modifier *pm, int speed)
-{
- png_byte colour_type = 0;
- png_byte bit_depth = 0;
-
- /* Ignore palette images - the gamma correction happens on the palette entry,
- * haven't got the tests for this yet.
- */
- while (next_format(&colour_type, &bit_depth)) if (colour_type != 3)
- {
- unsigned int i, j;
-
- for (i=0; i<pm->ngammas; ++i) for (j=0; j<pm->ngammas; ++j) if (i != j)
- {
- gamma_transform_test(pm, colour_type, bit_depth, pm->interlace_type,
- 1/pm->gammas[i], pm->gammas[j], bit_depth, speed,
- pm->use_input_precision, 0 /*do not strip16*/);
-
- if (fail(pm))
- return;
- }
- }
-}
-
-static void perform_gamma_sbit_tests(png_modifier *pm, int speed)
-{
- png_byte sbit;
-
- /* The only interesting cases are colour and grayscale, alpha is ignored here
- * for overall speed. Only bit depths 8 and 16 are tested.
- */
- for (sbit=pm->sbitlow; sbit<(1<<READ_BDHI); ++sbit)
- {
- unsigned int i, j;
-
- for (i=0; i<pm->ngammas; ++i)
- {
- for (j=0; j<pm->ngammas; ++j)
- {
- if (i != j)
- {
- if (sbit < 8)
- {
- gamma_transform_test(pm, 0, 8, pm->interlace_type,
- 1/pm->gammas[i], pm->gammas[j], sbit, speed,
- pm->use_input_precision_sbit, 0 /*strip16*/);
-
- if (fail(pm))
- return;
-
- gamma_transform_test(pm, 2, 8, pm->interlace_type,
- 1/pm->gammas[i], pm->gammas[j], sbit, speed,
- pm->use_input_precision_sbit, 0 /*strip16*/);
-
- if (fail(pm))
- return;
- }
-
-#ifdef DO_16BIT
- gamma_transform_test(pm, 0, 16, pm->interlace_type,
- 1/pm->gammas[i], pm->gammas[j], sbit, speed,
- pm->use_input_precision_sbit, 0 /*strip16*/);
-
- if (fail(pm))
- return;
-
- gamma_transform_test(pm, 2, 16, pm->interlace_type,
- 1/pm->gammas[i], pm->gammas[j], sbit, speed,
- pm->use_input_precision_sbit, 0 /*strip16*/);
-
- if (fail(pm))
- return;
-#endif
- }
- }
- }
- }
-}
-
-/* Note that this requires a 16 bit source image but produces 8 bit output, so
- * we only need the 16bit write support.
- */
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-static void perform_gamma_strip16_tests(png_modifier *pm, int speed)
-{
-# ifndef PNG_MAX_GAMMA_8
-# define PNG_MAX_GAMMA_8 11
-# endif
- /* Include the alpha cases here. Note that sbit matches the internal value
- * used by the library - otherwise we will get spurious errors from the
- * internal sbit style approximation.
- *
- * The threshold test is here because otherwise the 16 to 8 conversion will
- * proceed *without* gamma correction, and the tests above will fail (but not
- * by much) - this could be fixed, it only appears with the -g option.
- */
- unsigned int i, j;
- for (i=0; i<pm->ngammas; ++i)
- {
- for (j=0; j<pm->ngammas; ++j)
- {
- if (i != j &&
- fabs(pm->gammas[j]/pm->gammas[i]-1) >= PNG_GAMMA_THRESHOLD)
- {
- gamma_transform_test(pm, 0, 16, pm->interlace_type, 1/pm->gammas[i],
- pm->gammas[j], PNG_MAX_GAMMA_8, speed,
- pm->use_input_precision_16to8, 1 /*strip16*/);
-
- if (fail(pm))
- return;
-
- gamma_transform_test(pm, 2, 16, pm->interlace_type, 1/pm->gammas[i],
- pm->gammas[j], PNG_MAX_GAMMA_8, speed,
- pm->use_input_precision_16to8, 1 /*strip16*/);
-
- if (fail(pm))
- return;
-
- gamma_transform_test(pm, 4, 16, pm->interlace_type, 1/pm->gammas[i],
- pm->gammas[j], PNG_MAX_GAMMA_8, speed,
- pm->use_input_precision_16to8, 1 /*strip16*/);
-
- if (fail(pm))
- return;
-
- gamma_transform_test(pm, 6, 16, pm->interlace_type, 1/pm->gammas[i],
- pm->gammas[j], PNG_MAX_GAMMA_8, speed,
- pm->use_input_precision_16to8, 1 /*strip16*/);
-
- if (fail(pm))
- return;
- }
- }
- }
-}
-#endif /* 16 to 8 bit conversion */
-
-static void
-perform_gamma_test(png_modifier *pm, int speed, int summary)
-{
- /* First some arbitrary no-transform tests: */
- if (!speed && pm->test_gamma_threshold)
- {
- perform_gamma_threshold_tests(pm);
-
- if (fail(pm))
- return;
- }
-
- /* Now some real transforms. */
- if (pm->test_gamma_transform)
- {
- perform_gamma_transform_tests(pm, speed);
-
- if (summary)
- {
- printf("Gamma correction error summary\n\n");
- printf("The printed value is the maximum error in the pixel values\n");
- printf("calculated by the libpng gamma correction code. The error\n");
- printf("is calculated as the difference between the output pixel\n");
- printf("value (always an integer) and the ideal value from the\n");
- printf("libpng specification (typically not an integer).\n\n");
-
- printf("Expect this value to be less than .5 for 8 bit formats,\n");
- printf("less than 1 for formats with fewer than 8 bits and a small\n");
- printf("number (typically less than 5) for the 16 bit formats.\n");
- printf("For performance reasons the value for 16 bit formats\n");
- printf("increases when the image file includes an sBIT chunk.\n\n");
-
- printf(" 2 bit gray: %.5f\n", pm->error_gray_2);
- printf(" 4 bit gray: %.5f\n", pm->error_gray_4);
- printf(" 8 bit gray: %.5f\n", pm->error_gray_8);
- printf(" 8 bit color: %.5f\n", pm->error_color_8);
-#ifdef DO_16BIT
- printf(" 16 bit gray: %.5f\n", pm->error_gray_16);
- printf(" 16 bit color: %.5f\n", pm->error_color_16);
-#endif
- }
- }
-
- /* The sbit tests produce much larger errors: */
- if (pm->test_gamma_sbit)
- {
- pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 =
- pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0;
- perform_gamma_sbit_tests(pm, speed);
-
- if (summary)
- {
- printf("Gamma correction with sBIT:\n");
-
- if (pm->sbitlow < 8U)
- {
- printf(" 2 bit gray: %.5f\n", pm->error_gray_2);
- printf(" 4 bit gray: %.5f\n", pm->error_gray_4);
- printf(" 8 bit gray: %.5f\n", pm->error_gray_8);
- printf(" 8 bit color: %.5f\n", pm->error_color_8);
- }
-
- #ifdef DO_16BIT
- printf(" 16 bit gray: %.5f\n", pm->error_gray_16);
- printf(" 16 bit color: %.5f\n", pm->error_color_16);
- #endif
- }
- }
-
-#ifdef PNG_READ_16_TO_8_SUPPORTED
- if (pm->test_gamma_strip16)
- {
- /* The 16 to 8 bit strip operations: */
- pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 =
- pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0;
- perform_gamma_strip16_tests(pm, speed);
-
- if (summary)
- {
- printf("Gamma correction with 16 to 8 bit reduction:\n");
- printf(" 16 bit gray: %.5f\n", pm->error_gray_16);
- printf(" 16 bit color: %.5f\n", pm->error_color_16);
- }
- }
-#endif
-}
-
-/* INTERLACE MACRO VALIDATION */
-/* This is copied verbatim from the specification, it is simply the pass
- * number in which each pixel in each 8x8 tile appears. The array must
- * be indexed adam7[y][x] and notice that the pass numbers are based at
- * 1, not 0 - the base libpng uses.
- */
-static PNG_CONST
-png_byte adam7[8][8] =
-{
- { 1,6,4,6,2,6,4,6 },
- { 7,7,7,7,7,7,7,7 },
- { 5,6,5,6,5,6,5,6 },
- { 7,7,7,7,7,7,7,7 },
- { 3,6,4,6,3,6,4,6 },
- { 7,7,7,7,7,7,7,7 },
- { 5,6,5,6,5,6,5,6 },
- { 7,7,7,7,7,7,7,7 }
-};
-
-/* This routine validates all the interlace support macros in png.h for
- * a variety of valid PNG widths and heights. It uses a number of similarly
- * named internal routines that feed off the above array.
- */
-static png_uint_32
-png_pass_start_row(int pass)
-{
- int x, y;
- ++pass;
- for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass)
- return y;
- return 0xf;
-}
-
-static png_uint_32
-png_pass_start_col(int pass)
-{
- int x, y;
- ++pass;
- for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass)
- return x;
- return 0xf;
-}
-
-static int
-png_pass_row_shift(int pass)
-{
- int x, y, base=(-1), inc=8;
- ++pass;
- for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass)
- {
- if (base == (-1))
- base = y;
- else if (base == y)
- {}
- else if (inc == y-base)
- base=y;
- else if (inc == 8)
- inc = y-base, base=y;
- else if (inc != y-base)
- return 0xff; /* error - more than one 'inc' value! */
- }
-
- if (base == (-1)) return 0xfe; /* error - no row in pass! */
-
- /* The shift is always 1, 2 or 3 - no pass has all the rows! */
- switch (inc)
- {
-case 2: return 1;
-case 4: return 2;
-case 8: return 3;
-default: break;
- }
-
- /* error - unrecognized 'inc' */
- return (inc << 8) + 0xfd;
-}
-
-static int
-png_pass_col_shift(int pass)
-{
- int x, y, base=(-1), inc=8;
- ++pass;
- for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass)
- {
- if (base == (-1))
- base = x;
- else if (base == x)
- {}
- else if (inc == x-base)
- base=x;
- else if (inc == 8)
- inc = x-base, base=x;
- else if (inc != x-base)
- return 0xff; /* error - more than one 'inc' value! */
- }
-
- if (base == (-1)) return 0xfe; /* error - no row in pass! */
-
- /* The shift is always 1, 2 or 3 - no pass has all the rows! */
- switch (inc)
- {
-case 1: return 0; /* pass 7 has all the columns */
-case 2: return 1;
-case 4: return 2;
-case 8: return 3;
-default: break;
- }
-
- /* error - unrecognized 'inc' */
- return (inc << 8) + 0xfd;
-}
-
-static png_uint_32
-png_row_from_pass_row(png_uint_32 yIn, int pass)
-{
- /* By examination of the array: */
- switch (pass)
- {
-case 0: return yIn * 8;
-case 1: return yIn * 8;
-case 2: return yIn * 8 + 4;
-case 3: return yIn * 4;
-case 4: return yIn * 4 + 2;
-case 5: return yIn * 2;
-case 6: return yIn * 2 + 1;
-default: break;
- }
-
- return 0xff; /* bad pass number */
-}
-
-static png_uint_32
-png_col_from_pass_col(png_uint_32 xIn, int pass)
-{
- /* By examination of the array: */
- switch (pass)
- {
-case 0: return xIn * 8;
-case 1: return xIn * 8 + 4;
-case 2: return xIn * 4;
-case 3: return xIn * 4 + 2;
-case 4: return xIn * 2;
-case 5: return xIn * 2 + 1;
-case 6: return xIn;
-default: break;
- }
-
- return 0xff; /* bad pass number */
-}
-
-static int
-png_row_in_interlace_pass(png_uint_32 y, int pass)
-{
- /* Is row 'y' in pass 'pass'? */
- int x;
- y &= 7;
- ++pass;
- for (x=0; x<8; ++x) if (adam7[y][x] == pass)
- return 1;
-
- return 0;
-}
-
-static int
-png_col_in_interlace_pass(png_uint_32 x, int pass)
-{
- /* Is column 'x' in pass 'pass'? */
- int y;
- x &= 7;
- ++pass;
- for (y=0; y<8; ++y) if (adam7[y][x] == pass)
- return 1;
-
- return 0;
-}
-
-static png_uint_32
-png_pass_rows(png_uint_32 height, int pass)
-{
- png_uint_32 tiles = height>>3;
- png_uint_32 rows = 0;
- unsigned int x, y;
-
- height &= 7;
- ++pass;
- for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass)
- {
- rows += tiles;
- if (y < height) ++rows;
- break; /* i.e. break the 'x', column, loop. */
- }
-
- return rows;
-}
-
-static png_uint_32
-png_pass_cols(png_uint_32 width, int pass)
-{
- png_uint_32 tiles = width>>3;
- png_uint_32 cols = 0;
- unsigned int x, y;
-
- width &= 7;
- ++pass;
- for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass)
- {
- cols += tiles;
- if (x < width) ++cols;
- break; /* i.e. break the 'y', row, loop. */
- }
-
- return cols;
-}
-
-static void
-perform_interlace_macro_validation(void)
-{
- /* The macros to validate, first those that depend only on pass:
- *
- * PNG_PASS_START_ROW(pass)
- * PNG_PASS_START_COL(pass)
- * PNG_PASS_ROW_SHIFT(pass)
- * PNG_PASS_COL_SHIFT(pass)
- */
- int pass;
-
- for (pass=0; pass<7; ++pass)
- {
- png_uint_32 m, f, v;
-
- m = PNG_PASS_START_ROW(pass);
- f = png_pass_start_row(pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_PASS_START_ROW(%d) = %u != %x\n", pass, m, f);
- exit(1);
- }
-
- m = PNG_PASS_START_COL(pass);
- f = png_pass_start_col(pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_PASS_START_COL(%d) = %u != %x\n", pass, m, f);
- exit(1);
- }
-
- m = PNG_PASS_ROW_SHIFT(pass);
- f = png_pass_row_shift(pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_PASS_ROW_SHIFT(%d) = %u != %x\n", pass, m, f);
- exit(1);
- }
-
- m = PNG_PASS_COL_SHIFT(pass);
- f = png_pass_col_shift(pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_PASS_COL_SHIFT(%d) = %u != %x\n", pass, m, f);
- exit(1);
- }
-
- /* Macros that depend on the image or sub-image height too:
- *
- * PNG_PASS_ROWS(height, pass)
- * PNG_PASS_COLS(width, pass)
- * PNG_ROW_FROM_PASS_ROW(yIn, pass)
- * PNG_COL_FROM_PASS_COL(xIn, pass)
- * PNG_ROW_IN_INTERLACE_PASS(y, pass)
- * PNG_COL_IN_INTERLACE_PASS(x, pass)
- */
- for (v=0;;)
- {
- /* First the base 0 stuff: */
- m = PNG_ROW_FROM_PASS_ROW(v, pass);
- f = png_row_from_pass_row(v, pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n",
- v, pass, m, f);
- exit(1);
- }
-
- m = PNG_COL_FROM_PASS_COL(v, pass);
- f = png_col_from_pass_col(v, pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n",
- v, pass, m, f);
- exit(1);
- }
-
- m = PNG_ROW_IN_INTERLACE_PASS(v, pass);
- f = png_row_in_interlace_pass(v, pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_ROW_IN_INTERLACE_PASS(%u, %d) = %u != %x\n",
- v, pass, m, f);
- exit(1);
- }
-
- m = PNG_COL_IN_INTERLACE_PASS(v, pass);
- f = png_col_in_interlace_pass(v, pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_COL_IN_INTERLACE_PASS(%u, %d) = %u != %x\n",
- v, pass, m, f);
- exit(1);
- }
-
- /* Then the base 1 stuff: */
- ++v;
- m = PNG_PASS_ROWS(v, pass);
- f = png_pass_rows(v, pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_PASS_ROWS(%u, %d) = %u != %x\n",
- v, pass, m, f);
- exit(1);
- }
-
- m = PNG_PASS_COLS(v, pass);
- f = png_pass_cols(v, pass);
- if (m != f)
- {
- fprintf(stderr, "PNG_PASS_COLS(%u, %d) = %u != %x\n",
- v, pass, m, f);
- exit(1);
- }
-
- /* Move to the next v - the stepping algorithm starts skipping
- * values above 1024.
- */
- if (v > 1024)
- {
- if (v == PNG_UINT_31_MAX)
- break;
-
- v = (v << 1) ^ v;
- if (v >= PNG_UINT_31_MAX)
- v = PNG_UINT_31_MAX-1;
- }
- }
- }
-}
-
-/* main program */
-int main(int argc, PNG_CONST char **argv)
-{
- volatile int summary = 1; /* Print the error summary at the end */
-
- /* Create the given output file on success: */
- PNG_CONST char *volatile touch = NULL;
-
- /* This is an array of standard gamma values (believe it or not I've seen
- * every one of these mentioned somewhere.)
- *
- * In the following list the most useful values are first!
- */
- static double
- gammas[]={2.2, 1.0, 2.2/1.45, 1.8, 1.5, 2.4, 2.5, 2.62, 2.9};
-
- png_modifier pm;
- context(&pm.this, fault);
-
- modifier_init(&pm);
-
- /* Preallocate the image buffer, because we know how big it needs to be,
- * note that, for testing purposes, it is deliberately mis-aligned.
- */
- pm.this.image = malloc(2*TRANSFORM_IMAGEMAX+1);
-
- if (pm.this.image != NULL)
- {
- /* Ignore OOM at this point - the 'ensure' routine above will allocate
- * the array appropriately.
- */
- ++(pm.this.image);
- pm.this.cb_image = 2*TRANSFORM_IMAGEMAX;
- }
-
- /* Default to error on warning: */
- pm.this.treat_warnings_as_errors = 1;
-
- /* Store the test gammas */
- pm.gammas = gammas;
- pm.ngammas = 0; /* default to off */
- pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */
- pm.use_input_precision_16to8 = 1U; /* Because of the way libpng does it */
-
- /* Some default values (set the behavior for 'make check' here).
- * These values simply control the maximum error permitted in the gamma
- * transformations. The practial limits for human perception are described
- * below (the setting for maxpc16), however for 8 bit encodings it isn't
- * possible to meet the accepted capabilities of human vision - i.e. 8 bit
- * images can never be good enough, regardless of encoding.
- */
- pm.maxout8 = .1; /* Arithmetic error in *encoded* value */
- pm.maxabs8 = .00005; /* 1/20000 */
- pm.maxpc8 = .499; /* I.e., .499% fractional error */
- pm.maxout16 = .499; /* Error in *encoded* value */
- pm.maxabs16 = .00005;/* 1/20000 */
-
- /* NOTE: this is a reasonable perceptual limit. We assume that humans can
- * perceive light level differences of 1% over a 100:1 range, so we need to
- * maintain 1 in 10000 accuracy (in linear light space), which is what the
- * following guarantees. It also allows significantly higher errors at
- * higher 16 bit values, which is important for performance. The actual
- * maximum 16 bit error is about +/-1.9 in the fixed point implementation but
- * this is only allowed for values >38149 by the following:
- */
- pm.maxpc16 = .005; /* I.e., 1/200% - 1/20000 */
-
- /* Now parse the command line options. */
- while (--argc >= 1)
- {
- if (strcmp(*++argv, "-v") == 0)
- pm.this.verbose = 1;
-
- else if (strcmp(*argv, "-l") == 0)
- pm.log = 1;
-
- else if (strcmp(*argv, "-q") == 0)
- summary = pm.this.verbose = pm.log = 0;
-
- else if (strcmp(*argv, "-w") == 0)
- pm.this.treat_warnings_as_errors = 0;
-
- else if (strcmp(*argv, "--speed") == 0)
- pm.this.speed = 1, pm.ngammas = (sizeof gammas)/(sizeof gammas[0]),
- pm.test_standard = 0;
-
- else if (strcmp(*argv, "--size") == 0)
- pm.test_size = 1;
-
- else if (strcmp(*argv, "--nosize") == 0)
- pm.test_size = 0;
-
- else if (strcmp(*argv, "--standard") == 0)
- pm.test_standard = 1;
-
- else if (strcmp(*argv, "--nostandard") == 0)
- pm.test_standard = 0;
-
- else if (strcmp(*argv, "--transform") == 0)
- pm.test_transform = 1;
-
- else if (strcmp(*argv, "--notransform") == 0)
- pm.test_transform = 0;
-
- else if (strncmp(*argv, "--transform-disable=",
- sizeof "--transform-disable") == 0)
- {
- pm.test_transform = 1;
- transform_disable(*argv + sizeof "--transform-disable");
- }
-
- else if (strncmp(*argv, "--transform-enable=",
- sizeof "--transform-enable") == 0)
- {
- pm.test_transform = 1;
- transform_enable(*argv + sizeof "--transform-enable");
- }
-
- else if (strcmp(*argv, "--gamma") == 0)
- {
- /* Just do two gamma tests here (2.2 and linear) for speed: */
- pm.ngammas = 2U;
- pm.test_gamma_threshold = 1;
- pm.test_gamma_transform = 1;
- pm.test_gamma_sbit = 1;
- pm.test_gamma_strip16 = 1;
- }
-
- else if (strcmp(*argv, "--nogamma") == 0)
- pm.ngammas = 0;
-
- else if (strcmp(*argv, "--gamma-threshold") == 0)
- pm.ngammas = 2U, pm.test_gamma_threshold = 1;
-
- else if (strcmp(*argv, "--nogamma-threshold") == 0)
- pm.test_gamma_threshold = 0;
-
- else if (strcmp(*argv, "--gamma-transform") == 0)
- pm.ngammas = 2U, pm.test_gamma_transform = 1;
-
- else if (strcmp(*argv, "--nogamma-transform") == 0)
- pm.test_gamma_transform = 0;
-
- else if (strcmp(*argv, "--gamma-sbit") == 0)
- pm.ngammas = 2U, pm.test_gamma_sbit = 1;
-
- else if (strcmp(*argv, "--nogamma-sbit") == 0)
- pm.test_gamma_sbit = 0;
-
- else if (strcmp(*argv, "--gamma-16-to-8") == 0)
- pm.ngammas = 2U, pm.test_gamma_strip16 = 1;
-
- else if (strcmp(*argv, "--nogamma-16-to-8") == 0)
- pm.test_gamma_strip16 = 0;
-
- else if (strcmp(*argv, "--all-gammas") == 0)
- pm.ngammas = (sizeof gammas)/(sizeof gammas[0]);
-
- else if (strcmp(*argv, "--progressive-read") == 0)
- pm.this.progressive = 1;
-
- else if (strcmp(*argv, "--interlace") == 0)
- pm.interlace_type = PNG_INTERLACE_ADAM7;
-
- else if (argc >= 1 && strcmp(*argv, "--sbitlow") == 0)
- --argc, pm.sbitlow = (png_byte)atoi(*++argv);
-
- else if (argc >= 1 && strcmp(*argv, "--touch") == 0)
- --argc, touch = *++argv;
-
- else if (argc >= 1 && strncmp(*argv, "--max", 4) == 0)
- {
- --argc;
-
- if (strcmp(4+*argv, "abs8") == 0)
- pm.maxabs8 = atof(*++argv);
-
- else if (strcmp(4+*argv, "abs16") == 0)
- pm.maxabs16 = atof(*++argv);
-
- else if (strcmp(4+*argv, "out8") == 0)
- pm.maxout8 = atof(*++argv);
-
- else if (strcmp(4+*argv, "out16") == 0)
- pm.maxout16 = atof(*++argv);
-
- else if (strcmp(4+*argv, "pc8") == 0)
- pm.maxpc8 = atof(*++argv);
-
- else if (strcmp(4+*argv, "pc16") == 0)
- pm.maxpc16 = atof(*++argv);
-
- else
- {
- fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv);
- exit(1);
- }
- }
-
- else
- {
- fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv);
- exit(1);
- }
- }
-
- /* If pngvalid is run with no arguments default to a reasonable set of the
- * tests.
- */
- if (pm.test_standard == 0 && pm.test_size == 0 && pm.test_transform == 0 &&
- pm.ngammas == 0)
- {
- pm.test_standard = 1;
- pm.test_size = 1;
- pm.test_transform = 1;
- pm.ngammas = 3U;
- }
-
- if (pm.ngammas > 0 &&
- pm.test_gamma_threshold == 0 && pm.test_gamma_transform == 0 &&
- pm.test_gamma_sbit == 0 && pm.test_gamma_strip16 == 0)
- {
- pm.test_gamma_threshold = 1;
- pm.test_gamma_transform = 1;
- pm.test_gamma_sbit = 1;
- pm.test_gamma_strip16 = 1;
- }
-
- else if (pm.ngammas == 0)
- {
- /* Nothing to test so turn everything off: */
- pm.test_gamma_threshold = 0;
- pm.test_gamma_transform = 0;
- pm.test_gamma_sbit = 0;
- pm.test_gamma_strip16 = 0;
- }
-
- Try
- {
- /* Make useful base images */
- make_transform_images(&pm.this);
-
- /* Perform the standard and gamma tests. */
- if (pm.test_standard)
- {
- perform_interlace_macro_validation();
- perform_standard_test(&pm);
- perform_error_test(&pm);
- }
-
- /* Various oddly sized images: */
- if (pm.test_size)
- {
- make_size_images(&pm.this);
- perform_size_test(&pm);
- }
-
- /* Combinatorial transforms: */
- if (pm.test_transform)
- perform_transform_test(&pm);
-
- if (pm.ngammas > 0)
- perform_gamma_test(&pm, pm.this.speed != 0,
- summary && !pm.this.speed);
- }
-
- Catch(fault)
- {
- fprintf(stderr, "pngvalid: test aborted (probably failed in cleanup)\n");
- if (!pm.this.verbose)
- {
- if (pm.this.error[0] != 0)
- fprintf(stderr, "pngvalid: first error: %s\n", pm.this.error);
-
- fprintf(stderr, "pngvalid: run with -v to see what happened\n");
- }
- exit(1);
- }
-
- if (summary && !pm.this.speed)
- {
- printf("Results using %s point arithmetic %s\n",
-#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || PNG_LIBPNG_VER < 10500
- "floating",
-#else
- "fixed",
-#endif
- (pm.this.nerrors || (pm.this.treat_warnings_as_errors &&
- pm.this.nwarnings)) ? "(errors)" : (pm.this.nwarnings ?
- "(warnings)" : "(no errors or warnings)")
- );
- printf("Allocated memory statistics (in bytes):\n"
- "\tread %lu maximum single, %lu peak, %lu total\n"
- "\twrite %lu maximum single, %lu peak, %lu total\n",
- (unsigned long)pm.this.read_memory_pool.max_max,
- (unsigned long)pm.this.read_memory_pool.max_limit,
- (unsigned long)pm.this.read_memory_pool.max_total,
- (unsigned long)pm.this.write_memory_pool.max_max,
- (unsigned long)pm.this.write_memory_pool.max_limit,
- (unsigned long)pm.this.write_memory_pool.max_total);
- }
-
- /* Do this here to provoke memory corruption errors in memory not directly
- * allocated by libpng - not a complete test, but better than nothing.
- */
- store_delete(&pm.this);
-
- /* Error exit if there are any errors, and maybe if there are any
- * warnings.
- */
- if (pm.this.nerrors || (pm.this.treat_warnings_as_errors &&
- pm.this.nwarnings))
- {
- if (!pm.this.verbose)
- fprintf(stderr, "pngvalid: %s\n", pm.this.error);
-
- fprintf(stderr, "pngvalid: %d errors, %d warnings\n", pm.this.nerrors,
- pm.this.nwarnings);
-
- exit(1);
- }
-
- /* Success case. */
- if (touch != NULL)
- {
- FILE *fsuccess = fopen(touch, "wt");
-
- if (fsuccess != NULL)
- {
- int error = 0;
- fprintf(fsuccess, "PNG validation succeeded\n");
- fflush(fsuccess);
- error = ferror(fsuccess);
-
- if (fclose(fsuccess) || error)
- {
- fprintf(stderr, "%s: write failed\n", touch);
- exit(1);
- }
- }
- }
-
- return 0;
-}