• 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