rockbox/lib/rbcodec/codecs/libtremor/codebook.h

/********************************************************************
 *                                                                  *
 * THIS FILE IS PART OF THE OggVorbis 'TREMOR' 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 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002    *
 * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
 *                                                                  *
 ********************************************************************

 function: basic shared codebook operations

 ********************************************************************/

#ifndef _V_CODEBOOK_H_
#define _V_CODEBOOK_H_

#include "ogg.h"

/* This structure encapsulates huffman and VQ style encoding books; it
   doesn't do anything specific to either.

   valuelist/quantlist are nonNULL (and q_* significant) only if
   there's entry->value mapping to be done.

   If encode-side mapping must be done (and thus the entry needs to be
   hunted), the auxiliary encode pointer will point to a decision
   tree.  This is true of both VQ and huffman, but is mostly useful
   with VQ.

*/

typedef struct static_codebook{
  long   dim;            /* codebook dimensions (elements per vector) */
  long   entries;        /* codebook entries */
  long  *lengthlist;     /* codeword lengths in bits */

  /* mapping ***************************************************************/
  int    maptype;        /* 0=none
                            1=implicitly populated values from map column 
                            2=listed arbitrary values */

  /* The below does a linear, single monotonic sequence mapping. */
  long     q_min;       /* packed 32 bit float; quant value 0 maps to minval */
  long     q_delta;     /* packed 32 bit float; val 1 - val 0 == delta */
  int      q_quant;     /* bits: 0 < quant <= 16 */
  int      q_sequencep; /* bitflag */

  long     *quantlist;  /* map == 1: (int)(entries^(1/dim)) element column map
                           map == 2: list of dim*entries quantized entry vals
                        */
} static_codebook;

typedef struct codebook{
  long dim;           /* codebook dimensions (elements per vector) */
  long entries;       /* codebook entries */
  long used_entries;  /* populated codebook entries */

  /* the below are ordered by bitreversed codeword and only used
     entries are populated */
  int           binarypoint;
  ogg_int32_t  *valuelist;  /* list of dim*entries actual entry values */  
  ogg_uint32_t *codelist;   /* list of bitstream codewords for each entry */

  int          *dec_index;  
  char         *dec_codelengths;
  ogg_uint32_t *dec_firsttable;
  int           dec_firsttablen;
  int           dec_maxlength;

  long     q_min;       /* packed 32 bit float; quant value 0 maps to minval */
  long     q_delta;     /* packed 32 bit float; val 1 - val 0 == delta */

} codebook;

extern void vorbis_staticbook_destroy(static_codebook *b);
extern int vorbis_book_init_decode(codebook *dest,const static_codebook *source);

extern void vorbis_book_clear(codebook *b);
extern long _book_maptype1_quantvals(const static_codebook *b);

extern static_codebook *vorbis_staticbook_unpack(oggpack_buffer *b);

extern long vorbis_book_decode(codebook *book, oggpack_buffer *b);
extern long vorbis_book_decodevs_add(codebook *book, ogg_int32_t *a, 
                                     oggpack_buffer *b,int n,int point);
extern long vorbis_book_decodev_set(codebook *book, ogg_int32_t *a, 
                                    oggpack_buffer *b,int n,int point);
extern long vorbis_book_decodev_add(codebook *book, ogg_int32_t *a, 
                                    oggpack_buffer *b,int n,int point);
extern long vorbis_book_decodevv_add(codebook *book, ogg_int32_t **a,
                                     long off,int ch, 
                                    oggpack_buffer *b,int n,int point);

extern int _ilog(unsigned int v);


#endif