1 files changed, 79 insertions, 0 deletions
diff --git a/vorbis/lib/envelope.h b/vorbis/lib/envelope.h
new file mode 100644
index 0000000..f466efd
--- /dev/null
+++ b/vorbis/lib/envelope.h
@@ -0,0 +1,79 @@
+/********************************************************************
+ *                                                                  *
+ * THIS FILE IS PART OF THE OggVorbis 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 OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * by the Xiph.Org Foundation http://www.xiph.org/                  *
+ *                                                                  *
+ ********************************************************************
+
+ function: PCM data envelope analysis and manipulation
+
+ ********************************************************************/
+
+#ifndef _V_ENVELOPE_
+#define _V_ENVELOPE_
+
+#include "mdct.h"
+
+#define VE_PRE    16
+#define VE_WIN    4
+#define VE_POST   2
+#define VE_AMP    (VE_PRE+VE_POST-1)
+
+#define VE_BANDS  7
+#define VE_NEARDC 15
+
+#define VE_MINSTRETCH 2   /* a bit less than short block */
+#define VE_MAXSTRETCH 12  /* one-third full block */
+
+typedef struct {
+  float ampbuf[VE_AMP];
+  int   ampptr;
+
+  float nearDC[VE_NEARDC];
+  float nearDC_acc;
+  float nearDC_partialacc;
+  int   nearptr;
+
+} envelope_filter_state;
+
+typedef struct {
+  int begin;
+  int end;
+  float *window;
+  float total;
+} envelope_band;
+
+typedef struct {
+  int ch;
+  int winlength;
+  int searchstep;
+  float minenergy;
+
+  mdct_lookup  mdct;
+  float       *mdct_win;
+
+  envelope_band          band[VE_BANDS];
+  envelope_filter_state *filter;
+  int   stretch;
+
+  int                   *mark;
+
+  long storage;
+  long current;
+  long curmark;
+  long cursor;
+} envelope_lookup;
+
+extern void _ve_envelope_init(envelope_lookup *e,vorbis_info *vi);
+extern void _ve_envelope_clear(envelope_lookup *e);
+extern long _ve_envelope_search(vorbis_dsp_state *v);
+extern void _ve_envelope_shift(envelope_lookup *e,long shift);
+extern int  _ve_envelope_mark(vorbis_dsp_state *v);
+
+
+#endif