ref: f881d4f67254359ef348376e092c779993f57ed6
dir: /sys/src/cmd/audio/libvorbis/codebook.h/
/********************************************************************
* *
* 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 1994-2015 *
* by the Xiph.Org Foundation https://xiph.org/ *
* *
********************************************************************
function: basic shared codebook operations
********************************************************************/
#ifndef _V_CODEBOOK_H_
#define _V_CODEBOOK_H_
#include <ogg/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 */
char *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
*/
int allocedp;
} static_codebook;
typedef struct codebook{
long dim; /* codebook dimensions (elements per vector) */
long entries; /* codebook entries */
long used_entries; /* populated codebook entries */
const static_codebook *c;
/* for encode, the below are entry-ordered, fully populated */
/* for decode, the below are ordered by bitreversed codeword and only
used entries are populated */
float *valuelist; /* list of dim*entries actual entry values */
ogg_uint32_t *codelist; /* list of bitstream codewords for each entry */
int *dec_index; /* only used if sparseness collapsed */
char *dec_codelengths;
ogg_uint32_t *dec_firsttable;
int dec_firsttablen;
int dec_maxlength;
/* The current encoder uses only centered, integer-only lattice books. */
int quantvals;
int minval;
int delta;
} codebook;
extern void vorbis_staticbook_destroy(static_codebook *b);
extern int vorbis_book_init_encode(codebook *dest,const static_codebook *source);
extern int vorbis_book_init_decode(codebook *dest,const static_codebook *source);
extern void vorbis_book_clear(codebook *b);
extern float *_book_unquantize(const static_codebook *b,int n,int *map);
extern float *_book_logdist(const static_codebook *b,float *vals);
extern float _float32_unpack(long val);
extern long _float32_pack(float val);
extern int _best(codebook *book, float *a, int step);
extern long _book_maptype1_quantvals(const static_codebook *b);
extern int vorbis_book_besterror(codebook *book,float *a,int step,int addmul);
extern long vorbis_book_codeword(codebook *book,int entry);
extern long vorbis_book_codelen(codebook *book,int entry);
extern int vorbis_staticbook_pack(const static_codebook *c,oggpack_buffer *b);
extern static_codebook *vorbis_staticbook_unpack(oggpack_buffer *b);
extern int vorbis_book_encode(codebook *book, int a, oggpack_buffer *b);
extern long vorbis_book_decode(codebook *book, oggpack_buffer *b);
extern long vorbis_book_decodevs_add(codebook *book, float *a,
oggpack_buffer *b,int n);
extern long vorbis_book_decodev_set(codebook *book, float *a,
oggpack_buffer *b,int n);
extern long vorbis_book_decodev_add(codebook *book, float *a,
oggpack_buffer *b,int n);
extern long vorbis_book_decodevv_add(codebook *book, float **a,
long off,int ch,
oggpack_buffer *b,int n);
#endif