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author | FWoltermann@gmail.com <FWoltermann@gmail.com@076cb2c4-205e-83fd-5cf3-1be9aa105544> | 2011-12-08 14:53:40 +0000 |
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committer | FWoltermann@gmail.com <FWoltermann@gmail.com@076cb2c4-205e-83fd-5cf3-1be9aa105544> | 2011-12-08 14:53:40 +0000 |
commit | e33e19d0587146859d48a134ec9fd94e7b7ba5cd (patch) | |
tree | 69d048c8801858d2756ab3a487090a7a1b74bf14 /oggvorbis/include/theora | |
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Initial upload
Diffstat (limited to 'oggvorbis/include/theora')
-rw-r--r-- | oggvorbis/include/theora/theora.h | 539 |
1 files changed, 539 insertions, 0 deletions
diff --git a/oggvorbis/include/theora/theora.h b/oggvorbis/include/theora/theora.h new file mode 100644 index 0000000..8c4f883 --- /dev/null +++ b/oggvorbis/include/theora/theora.h @@ -0,0 +1,539 @@ +/******************************************************************** + * * + * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. * + * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * + * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * + * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * + * * + * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2003 * + * by the Xiph.Org Foundation http://www.xiph.org/ * + * * + ******************************************************************** + + function: + last mod: $Id: theora.h,v 1.1.2.1 2006-12-25 21:44:11 taylor Exp $ + + ********************************************************************/ + +#ifndef _O_THEORA_H_ +#define _O_THEORA_H_ + +#ifdef __cplusplus +extern "C" +{ +#endif /* __cplusplus */ + +#ifndef LIBOGG2 +#include <ogg/ogg.h> +#else +#include <ogg2/ogg.h> +/* This is temporary until libogg2 is more complete */ +ogg_buffer_state *ogg_buffer_create(void); +#endif + +/** \mainpage + * + * \section intro Introduction + * + * This is the documentation for the libtheora C API. + * libtheora is the reference implementation for + * <a href="http://www.theora.org/">Theora</a>, a free video codec. + * Theora is derived from On2's VP3 codec with improved integration for + * Ogg multimedia formats by <a href="http://www.xiph.org/">Xiph.Org</a>. + */ + +/** \file + * The libtheora C API. + */ + +/** + * A YUV buffer for passing uncompressed frames to and from the codec. + * This holds a Y'CbCr frame in planar format. The CbCr planes can be + * subsampled and have their own separate dimensions and row stride + * offsets. Note that the strides may be negative in some + * configurations. For theora the width and height of the largest plane + * must be a multiple of 16. The actual meaningful picture size and + * offset are stored in the theora_info structure; frames returned by + * the decoder may need to be cropped for display. + * + * All samples are 8 bits. Within each plane samples are ordered by + * row from the top of the frame to the bottom. Within each row samples + * are ordered from left to right. + */ +typedef struct { + int y_width; /**< Width of the Y' luminance plane */ + int y_height; /**< Height of the luminance plane */ + int y_stride; /**< Offset in bytes between successive rows */ + + int uv_width; /**< Height of the Cb and Cr chroma planes */ + int uv_height; /**< Width of the chroma planes */ + int uv_stride; /**< Offset between successive chroma rows */ + unsigned char *y; /**< Pointer to start of luminance data */ + unsigned char *u; /**< Pointer to start of Cb data */ + unsigned char *v; /**< Pointer to start of Cr data */ + +} yuv_buffer; + +/** + * A Colorspace. + */ +typedef enum { + OC_CS_UNSPECIFIED, /**< The colorspace is unknown or unspecified */ + OC_CS_ITU_REC_470M, /**< This is the best option for 'NTSC' content */ + OC_CS_ITU_REC_470BG, /**< This is the best option for 'PAL' content */ + OC_CS_NSPACES /**< This marks the end of the defined colorspaces */ +} theora_colorspace; + +/** + * A Chroma subsampling + * + * These enumerate the available chroma subsampling options supported + * by the theora format. See Section 4.4 of the specification for + * exact definitions. + */ +typedef enum { + OC_PF_420, /**< Chroma subsampling by 2 in each direction (4:2:0) */ + OC_PF_RSVD, /**< Reserved value */ + OC_PF_422, /**< Horizonatal chroma subsampling by 2 (4:2:2) */ + OC_PF_444, /**< No chroma subsampling at all (4:4:4) */ +} theora_pixelformat; + +/** + * Theora bitstream info. + * Contains the basic playback parameters for a stream, + * corresponds to the initial 'info' header packet. + * + * Encoded theora frames must be a multiple of 16 is size; + * this is what the width and height members represent. To + * handle other sizes, a crop rectangle is specified in + * frame_height and frame_width, offset_x and offset_y. The + * offset and size should still be a multiple of 2 to avoid + * chroma sampling shifts. Offset values in this structure + * are measured from the upper left of the image. + * + * Frame rate, in frames per second, is stored as a rational + * fraction. So is the aspect ratio. Note that this refers + * to the aspect ratio of the frame pixels, not of the + * overall frame itself. + * + * see the example code for use of the other parameters and + * good default settings for the encoder parameters. + */ +typedef struct { + ogg_uint32_t width; /**< encoded frame width */ + ogg_uint32_t height; /**< encoded frame height */ + ogg_uint32_t frame_width; /**< display frame width */ + ogg_uint32_t frame_height; /**< display frame height */ + ogg_uint32_t offset_x; /**< horizontal offset of the displayed frame */ + ogg_uint32_t offset_y; /**< vertical offset of the displayed frame */ + ogg_uint32_t fps_numerator; /**< frame rate numerator **/ + ogg_uint32_t fps_denominator; /**< frame rate denominator **/ + ogg_uint32_t aspect_numerator; /**< pixel aspect ratio numerator */ + ogg_uint32_t aspect_denominator; /**< pixel aspect ratio denominator */ + theora_colorspace colorspace; /**< colorspace */ + int target_bitrate; /**< nominal bitrate in bits per second */ + int quality; /**< Nominal quality setting, 0-63 */ + int quick_p; /**< Quick encode/decode */ + + /* decode only */ + unsigned char version_major; + unsigned char version_minor; + unsigned char version_subminor; + + void *codec_setup; + + /* encode only */ + int dropframes_p; + int keyframe_auto_p; + ogg_uint32_t keyframe_frequency; + ogg_uint32_t keyframe_frequency_force; /* also used for decode init to + get granpos shift correct */ + ogg_uint32_t keyframe_data_target_bitrate; + ogg_int32_t keyframe_auto_threshold; + ogg_uint32_t keyframe_mindistance; + ogg_int32_t noise_sensitivity; + ogg_int32_t sharpness; + + theora_pixelformat pixelformat; /**< chroma subsampling mode to expect */ + +} theora_info; + +/** Codec internal state and context. + */ +typedef struct{ + theora_info *i; + ogg_int64_t granulepos; + + void *internal_encode; + void *internal_decode; + +} theora_state; + +/** + * Comment header metadata. + * + * This structure holds the in-stream metadata corresponding to + * the 'comment' header packet. + * + * Meta data is stored as a series of (tag, value) pairs, in + * length-encoded string vectors. The first occurence of the + * '=' character delimits the tag and value. A particular tag + * may occur more than once. The character set encoding for + * the strings is always utf-8, but the tag names are limited + * to case-insensitive ascii. See the spec for details. + * + * In filling in this structure, theora_decode_header() will + * null-terminate the user_comment strings for safety. However, + * the bitstream format itself treats them as 8-bit clean, + * and so the length array should be treated as authoritative + * for their length. + */ +typedef struct theora_comment{ + char **user_comments; /**< An array of comment string vectors */ + int *comment_lengths; /**< An array of corresponding string vector lengths in bytes */ + int comments; /**< The total number of comment string vectors */ + char *vendor; /**< The vendor string identifying the encoder, null terminated */ + +} theora_comment; + +#define OC_FAULT -1 /**< General failure */ +#define OC_EINVAL -10 /**< Library encountered invalid internal data */ +#define OC_DISABLED -11 /**< Requested action is disabled */ +#define OC_BADHEADER -20 /**< Header packet was corrupt/invalid */ +#define OC_NOTFORMAT -21 /**< Packet is not a theora packet */ +#define OC_VERSION -22 /**< Bitstream version is not handled */ +#define OC_IMPL -23 /**< Feature or action not implemented */ +#define OC_BADPACKET -24 /**< Packet is corrupt */ +#define OC_NEWPACKET -25 /**< Packet is an (ignorable) unhandled extension */ +#define OC_DUPFRAME 1 /**< Packet is a dropped frame */ + +/** + * Retrieve a human-readable string to identify the encoder vendor and version. + * \returns A version string. + */ +extern const char *theora_version_string(void); + +/** + * Retrieve a 32-bit version number. + * This number is composed of a 16-bit major version, 8-bit minor version + * and 8 bit sub-version, composed as follows: +<pre> + (VERSION_MAJOR<<16) + (VERSION_MINOR<<8) + (VERSION_SUB) +</pre> +* \returns The version number. +*/ +extern ogg_uint32_t theora_version_number(void); + +/** + * Initialize the theora encoder. + * \param th The theora_state handle to initialize for encoding. + * \param ti A theora_info struct filled with the desired encoding parameters. + * \retval 0 Success + */ +extern int theora_encode_init(theora_state *th, theora_info *ti); + +/** + * Submit a YUV buffer to the theora encoder. + * \param t A theora_state handle previously initialized for encoding. + * \param yuv A buffer of YUV data to encode. + * \retval OC_EINVAL Encoder is not ready, or is finished. + * \retval -1 The size of the given frame differs from those previously input + * \retval 0 Success + */ +extern int theora_encode_YUVin(theora_state *t, yuv_buffer *yuv); + +/** + * Request the next packet of encoded video. + * The encoded data is placed in a user-provided ogg_packet structure. + * \param t A theora_state handle previously initialized for encoding. + * \param last_p whether this is the last packet the encoder should produce. + * \param op An ogg_packet structure to fill. libtheora will set all + * elements of this structure, including a pointer to encoded + * data. The memory for the encoded data is owned by libtheora. + * \retval 0 No internal storage exists OR no packet is ready + * \retval -1 The encoding process has completed + * \retval 1 Success + */ +extern int theora_encode_packetout( theora_state *t, int last_p, + ogg_packet *op); + +/** + * Request a packet containing the initial header. + * A pointer to the header data is placed in a user-provided ogg_packet + * structure. + * \param t A theora_state handle previously initialized for encoding. + * \param op An ogg_packet structure to fill. libtheora will set all + * elements of this structure, including a pointer to the header + * data. The memory for the header data is owned by libtheora. + * \retval 0 Success + */ +extern int theora_encode_header(theora_state *t, ogg_packet *op); + +/** + * Request a comment header packet from provided metadata. + * A pointer to the comment data is placed in a user-provided ogg_packet + * structure. + * \param tc A theora_comment structure filled with the desired metadata + * \param op An ogg_packet structure to fill. libtheora will set all + * elements of this structure, including a pointer to the encoded + * comment data. The memory for the comment data is owned by + * libtheora. + * \retval 0 Success + */ +extern int theora_encode_comment(theora_comment *tc, ogg_packet *op); + +/** + * Request a packet containing the codebook tables for the stream. + * A pointer to the codebook data is placed in a user-provided ogg_packet + * structure. + * \param t A theora_state handle previously initialized for encoding. + * \param op An ogg_packet structure to fill. libtheora will set all + * elements of this structure, including a pointer to the codebook + * data. The memory for the header data is owned by libtheora. + * \retval 0 Success + */ +extern int theora_encode_tables(theora_state *t, ogg_packet *op); + +/** + * Decode an Ogg packet, with the expectation that the packet contains + * an initial header, comment data or codebook tables. + * + * \param ci A theora_info structure to fill. This must have been previously + * initialized with theora_info_init(). If \a op contains an initial + * header, theora_decode_header() will fill \a ci with the + * parsed header values. If \a op contains codebook tables, + * theora_decode_header() will parse these and attach an internal + * representation to \a ci->codec_setup. + * \param cc A theora_comment structure to fill. If \a op contains comment + * data, theora_decode_header() will fill \a cc with the parsed + * comments. + * \param op An ogg_packet structure which you expect contains an initial + * header, comment data or codebook tables. + * + * \retval OC_BADHEADER \a op is NULL; OR the first byte of \a op->packet + * has the signature of an initial packet, but op is + * not a b_o_s packet; OR this packet has the signature + * of an initial header packet, but an initial header + * packet has already been seen; OR this packet has the + * signature of a comment packet, but the initial header + * has not yet been seen; OR this packet has the signature + * of a comment packet, but contains invalid data; OR + * this packet has the signature of codebook tables, + * but the initial header or comments have not yet + * been seen; OR this packet has the signature of codebook + * tables, but contains invalid data; + * OR the stream being decoded has a compatible version + * but this packet does not have the signature of a + * theora initial header, comments, or codebook packet + * \retval OC_VERSION The packet data of \a op is an initial header with + * a version which is incompatible with this version of + * libtheora. + * \retval OC_NEWPACKET the stream being decoded has an incompatible (future) + * version and contains an unknown signature. + * \retval 0 Success + * + * \note The normal usage is that theora_decode_header() be called on the + * first three packets of a theora logical bitstream in succession. + */ +extern int theora_decode_header(theora_info *ci, theora_comment *cc, + ogg_packet *op); + +/** + * Initialize a theora_state handle for decoding. + * \param th The theora_state handle to initialize. + * \param c A theora_info struct filled with the desired decoding parameters. + * This is of course usually obtained from a previous call to + * theora_decode_header(). + * \retval 0 Success + */ +extern int theora_decode_init(theora_state *th, theora_info *c); + +/** + * Input a packet containing encoded data into the theora decoder. + * \param th A theora_state handle previously initialized for decoding. + * \param op An ogg_packet containing encoded theora data. + * \retval 0 Success + * \retval OC_BADPACKET \a op does not contain encoded video data + */ +extern int theora_decode_packetin(theora_state *th,ogg_packet *op); + +/** + * Output the next available frame of decoded YUV data. + * \param th A theora_state handle previously initialized for decoding. + * \param yuv A yuv_buffer in which libtheora should place the decoded data. + * \retval 0 Success + */ +extern int theora_decode_YUVout(theora_state *th,yuv_buffer *yuv); + +/** + * Report whether a theora packet is a header or not + * This function does no verification beyond checking the header + * flag bit so it should not be used for bitstream identification; + * use theora_decode_header() for that. + * + * \param op An ogg_packet containing encoded theora data. + * \retval 1 The packet is a header packet + * \retval 0 The packet is not a header packet (and so contains frame data) + * + * Thus function was added in the 1.0alpha4 release. + */ +extern int theora_packet_isheader(ogg_packet *op); + +/** + * Report whether a theora packet is a keyframe or not + * + * \param op An ogg_packet containing encoded theora data. + * \retval 1 The packet contains a keyframe image + * \retval 0 The packet is contains an interframe delta + * \retval -1 The packet is not an image data packet at all + * + * Thus function was added in the 1.0alpha4 release. + */ +extern int theora_packet_iskeyframe(ogg_packet *op); + +/** + * Report the granulepos shift radix + * + * When embedded in Ogg, Theora uses a two-part granulepos, + * splitting the 64-bit field into two pieces. The more-significant + * section represents the frame count at the last keyframe, + * and the less-significant section represents the count of + * frames since the last keyframe. In this way the overall + * field is still non-decreasing with time, but usefully encodes + * a pointer to the last keyframe, which is necessary for + * correctly restarting decode after a seek. + * + * This function reports the number of bits used to represent + * the distance to the last keyframe, and thus how the granulepos + * field must be shifted or masked to obtain the two parts. + * + * Since libtheora returns compressed data in an ogg_packet + * structure, this may be generally useful even if the Theora + * packets are not being used in an Ogg container. + * + * \param ti A previously initialized theora_info struct + * \returns The bit shift dividing the two granulepos fields + * + * This function was added in the 1.0alpha5 release. + */ +int theora_granule_shift(theora_info *ti); + +/** + * Convert a granulepos to an absolute frame number. The granulepos is + * interpreted in the context of a given theora_state handle. + * + * \param th A previously initialized theora_state handle (encode or decode) + * \param granulepos The granulepos to convert. + * \returns The frame number corresponding to \a granulepos. + * \retval -1 The given granulepos is undefined (i.e. negative) + * + * Thus function was added in the 1.0alpha4 release. + */ +extern ogg_int64_t theora_granule_frame(theora_state *th,ogg_int64_t granulepos); + +/** + * Convert a granulepos to absolute time in seconds. The granulepos is + * interpreted in the context of a given theora_state handle. + * \param th A previously initialized theora_state handle (encode or decode) + * \param granulepos The granulepos to convert. + * \returns The absolute time in seconds corresponding to \a granulepos. + * \retval -1. The given granulepos is undefined (i.e. negative), or + * \retval -1. The function has been disabled because floating + * point support is not available. + */ +extern double theora_granule_time(theora_state *th,ogg_int64_t granulepos); + +/** + * Initialize a theora_info structure. All values within the given theora_info + * structure are initialized, and space is allocated within libtheora for + * internal codec setup data. + * \param c A theora_info struct to initialize. + */ +extern void theora_info_init(theora_info *c); + +/** + * Clear a theora_info structure. All values within the given theora_info + * structure are cleared, and associated internal codec setup data is freed. + * \param c A theora_info struct to initialize. + */ +extern void theora_info_clear(theora_info *c); + +/** + * Free all internal data associated with a theora_state handle. + * \param t A theora_state handle. + */ +extern void theora_clear(theora_state *t); + +/** + * Initialize an allocated theora_comment structure + * \param tc An allocated theora_comment structure + **/ +extern void theora_comment_init(theora_comment *tc); + +/** + * Add a comment to an initialized theora_comment structure + * \param tc A previously initialized theora comment structure + * \param comment A null-terminated string encoding the comment in the form + * "TAG=the value" + * + * Neither theora_comment_add() nor theora_comment_add_tag() support + * comments containing null values, although the bitstream format + * supports this. To add such comments you will need to manipulate + * the theora_comment structure directly. + **/ + +extern void theora_comment_add(theora_comment *tc, char *comment); + +/** + * Add a comment to an initialized theora_comment structure. + * \param tc A previously initialized theora comment structure + * \param tag A null-terminated string containing the tag + * associated with the comment. + * \param value The corresponding value as a null-terminated string + * + * Neither theora_comment_add() nor theora_comment_add_tag() support + * comments containing null values, although the bitstream format + * supports this. To add such comments you will need to manipulate + * the theora_comment structure directly. + **/ +extern void theora_comment_add_tag(theora_comment *tc, + char *tag, char *value); + +/** + * Look up a comment value by tag. + * \param tc Tn initialized theora_comment structure + * \param tag The tag to look up + * \param count The instance of the tag. The same tag can appear multiple + * times, each with a distinct and ordered value, so an index + * is required to retrieve them all. + * \returns A pointer to the queried tag's value + * \retval NULL No matching tag is found + * + * \note Use theora_comment_query_count() to get the legal range for the + * count parameter. + **/ + +extern char *theora_comment_query(theora_comment *tc, char *tag, int count); + +/** Look up the number of instances of a tag. + * \param tc An initialized theora_comment structure + * \param tag The tag to look up + * \returns The number on instances of a particular tag. + * + * Call this first when querying for a specific tag and then interate + * over the number of instances with separate calls to + * theora_comment_query() to retrieve all instances in order. + **/ +extern int theora_comment_query_count(theora_comment *tc, char *tag); + +/** + * Clear an allocated theora_comment struct so that it can be freed. + * \param tc An allocated theora_comment structure. + **/ +extern void theora_comment_clear(theora_comment *tc); + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* _O_THEORA_H_ */ |