tremor/ivorbiscodec.h

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *
   4  *                                                                  *
   5  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
   6  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
   7  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
   8  *                                                                  *
   9  * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002    *
  10  * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
  11  *                                                                  *
  12  ********************************************************************
  13
  14  function: libvorbis codec headers
  15
  16  ********************************************************************/
  17
  18 #ifndef _vorbis_codec_h_
  19 #define _vorbis_codec_h_
  20
  21 #ifdef __cplusplus
  22 extern "C"
  23 {
  24 #endif /* __cplusplus */
  25
  26 #include "ogg.h"
  27
  28 typedef struct vorbis_info{
  29   int version;
  30   int channels;
  31   long rate;
  32
  33   /* The below bitrate declarations are *hints*.
  34      Combinations of the three values carry the following implications:
  35
  36      all three set to the same value:
  37        implies a fixed rate bitstream
  38      only nominal set:
  39        implies a VBR stream that averages the nominal bitrate.  No hard
  40        upper/lower limit
  41      upper and or lower set:
  42        implies a VBR bitstream that obeys the bitrate limits. nominal
  43        may also be set to give a nominal rate.
  44      none set:
  45        the coder does not care to speculate.
  46   */
  47
  48   long bitrate_upper;
  49   long bitrate_nominal;
  50   long bitrate_lower;
  51   long bitrate_window;
  52
  53   void *codec_setup;
  54 } vorbis_info;
  55
  56 /* vorbis_dsp_state buffers the current vorbis audio
  57    analysis/synthesis state.  The DSP state belongs to a specific
  58    logical bitstream ****************************************************/
  59 typedef struct vorbis_dsp_state{
  60   int analysisp;
  61   vorbis_info *vi;
  62
  63   ogg_int32_t **pcm;
  64   ogg_int32_t **pcmret;
  65   int      pcm_storage;
  66   int      pcm_current;
  67   int      pcm_returned;
  68
  69   int  preextrapolate;
  70   int  eofflag;
  71
  72   long lW;
  73   long W;
  74   long nW;
  75   long centerW;
  76
  77   ogg_int64_t granulepos;
  78   ogg_int64_t sequence;
  79
  80   void       *backend_state;
  81 } vorbis_dsp_state;
  82
  83 typedef struct vorbis_block{
  84   /* necessary stream state for linking to the framing abstraction */
  85   ogg_int32_t  **pcm;       /* this is a pointer into local storage */
  86   oggpack_buffer opb;
  87
  88   long  lW;
  89   long  W;
  90   long  nW;
  91   int   pcmend;
  92   int   mode;
  93
  94   int         eofflag;
  95   ogg_int64_t granulepos;
  96   ogg_int64_t sequence;
  97   vorbis_dsp_state *vd; /* For read-only access of configuration */
  98
  99   /* local storage to avoid remallocing; it's up to the mapping to
 100      structure it */
 101   void               *localstore;
 102   long                localtop;
 103   long                localalloc;
 104   long                totaluse;
 105   struct alloc_chain *reap;
 106
 107 } vorbis_block;
 108
 109 /* vorbis_block is a single block of data to be processed as part of
 110 the analysis/synthesis stream; it belongs to a specific logical
 111 bitstream, but is independant from other vorbis_blocks belonging to
 112 that logical bitstream. *************************************************/
 113
 114 struct alloc_chain{
 115   void *ptr;
 116   struct alloc_chain *next;
 117 };
 118
 119 /* vorbis_info contains all the setup information specific to the
 120    specific compression/decompression mode in progress (eg,
 121    psychoacoustic settings, channel setup, options, codebook
 122    etc). vorbis_info and substructures are in backends.h.
 123 *********************************************************************/
 124
 125 /* the comments are not part of vorbis_info so that vorbis_info can be
 126    static storage */
 127 typedef struct vorbis_comment{
 128   /* unlimited user comment fields.  libvorbis writes 'libvorbis'
 129      whatever vendor is set to in encode */
 130   char **user_comments;
 131   int   *comment_lengths;
 132   int    comments;
 133   char  *vendor;
 134
 135 } vorbis_comment;
 136
 137
 138 /* libvorbis encodes in two abstraction layers; first we perform DSP
 139    and produce a packet (see docs/analysis.txt).  The packet is then
 140    coded into a framed OggSquish bitstream by the second layer (see
 141    docs/framing.txt).  Decode is the reverse process; we sync/frame
 142    the bitstream and extract individual packets, then decode the
 143    packet back into PCM audio.
 144
 145    The extra framing/packetizing is used in streaming formats, such as
 146    files.  Over the net (such as with UDP), the framing and
 147    packetization aren't necessary as they're provided by the transport
 148    and the streaming layer is not used */
 149
 150 /* Vorbis PRIMITIVES: general ***************************************/
 151
 152 extern void     vorbis_info_init(vorbis_info *vi);
 153 extern void     vorbis_info_clear(vorbis_info *vi);
 154 extern int      vorbis_info_blocksize(vorbis_info *vi,int zo);
 155 extern void     vorbis_comment_init(vorbis_comment *vc);
 156 extern void     vorbis_comment_add(vorbis_comment *vc, char *comment);
 157 extern void     vorbis_comment_add_tag(vorbis_comment *vc,
 158                                        char *tag, char *contents);
 159 extern char    *vorbis_comment_query(vorbis_comment *vc, char *tag, int count);
 160 extern int      vorbis_comment_query_count(vorbis_comment *vc, char *tag);
 161 extern void     vorbis_comment_clear(vorbis_comment *vc);
 162
 163 extern int      vorbis_block_init(vorbis_dsp_state *v, vorbis_block *vb);
 164 extern int      vorbis_block_clear(vorbis_block *vb);
 165 extern void     vorbis_dsp_clear(vorbis_dsp_state *v);
 166
 167 /* Vorbis PRIMITIVES: synthesis layer *******************************/
 168 extern int      vorbis_synthesis_headerin(vorbis_info *vi,vorbis_comment *vc,
 169                                           ogg_packet *op);
 170
 171 extern int      vorbis_synthesis_init(vorbis_dsp_state *v,vorbis_info *vi);
 172 extern int      vorbis_synthesis(vorbis_block *vb,ogg_packet *op);
 173 extern int      vorbis_synthesis_blockin(vorbis_dsp_state *v,vorbis_block *vb);
 174 extern int      vorbis_synthesis_pcmout(vorbis_dsp_state *v,ogg_int32_t ***pcm);
 175 extern int      vorbis_synthesis_read(vorbis_dsp_state *v,int samples);
 176 extern long     vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op);
 177
 178 /* Vorbis ERRORS and return codes ***********************************/
 179
 180 #define OV_FALSE      -1
 181 #define OV_EOF        -2
 182 #define OV_HOLE       -3
 183
 184 #define OV_EREAD      -128
 185 #define OV_EFAULT     -129
 186 #define OV_EIMPL      -130
 187 #define OV_EINVAL     -131
 188 #define OV_ENOTVORBIS -132
 189 #define OV_EBADHEADER -133
 190 #define OV_EVERSION   -134
 191 #define OV_ENOTAUDIO  -135
 192 #define OV_EBADPACKET -136
 193 #define OV_EBADLINK   -137
 194 #define OV_ENOSEEK    -138
 195
 196 #ifdef __cplusplus
 197 }
 198 #endif /* __cplusplus */
 199
 200 #endif
 201