quant.c

mediastreamer2是开源的网络传输媒体流的库

/********************************************************************
 *                                                                  *
 * THIS FILE IS PART OF THE OggTheora 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 Theora SOURCE CODE IS COPYRIGHT (C) 2002-2005                *
 * by the Xiph.Org Foundation http://www.xiph.org/                  *
 *                                                                  *
 ********************************************************************

  function:
  last mod: $Id: quant.c 11442 2006-05-27 17:28:08Z giles $

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

#include <stdlib.h>
#include <string.h>
#include "codec_internal.h"
#include "quant_lookup.h"

/* the *V1 tables are the originals used by the VP3 codec */

static const ogg_uint32_t QThreshTableV1[Q_TABLE_SIZE] = {
  500,  450,  400,  370,  340,  310, 285, 265,
  245,  225,  210,  195,  185,  180, 170, 160,
  150,  145,  135,  130,  125,  115, 110, 107,
  100,   96,   93,   89,   85,   82,  75,  74,
  70,   68,   64,   60,   57,   56,  52,  50,
  49,   45,   44,   43,   40,   38,  37,  35,
  33,   32,   30,   29,   28,   25,  24,  22,
  21,   19,   18,   17,   15,   13,  12,  10
};

static const Q_LIST_ENTRY DcScaleFactorTableV1[ Q_TABLE_SIZE ] = {
  220, 200, 190, 180, 170, 170, 160, 160,
  150, 150, 140, 140, 130, 130, 120, 120,
  110, 110, 100, 100, 90,  90,  90,  80,
  80,  80,  70,  70,  70,  60,  60,  60,
  60,  50,  50,  50,  50,  40,  40,  40,
  40,  40,  30,  30,  30,  30,  30,  30,
  30,  20,  20,  20,  20,  20,  20,  20,
  20,  10,  10,  10,  10,  10,  10,  10
};

/* dbm -- defined some alternative tables to test header packing */
#define NEW_QTABLES 0
#if NEW_QTABLES

static const Q_LIST_ENTRY Y_coeffsV1[64] =
{
        8,  16,  16,  16,  20,  20,  20,  20,
        16,  16,  16,  16,  20,  20,  20,  20,
        16,  16,  16,  16,  22,  22,  22,  22,
        16,  16,  16,  16,  22,  22,  22,  22,
        20,  20,  22,  22,  24,  24,  24,  24,
        20,  20,  22,  22,  24,  24,  24,  24,
        20,  20,  22,  22,  24,  24,  24,  24,
        20,  20,  22,  22,  24,  24,  24,  24
};

static const Q_LIST_ENTRY UV_coeffsV1[64] =
{       17,     18,     24,     47,     99,     99,     99,     99,
        18,     21,     26,     66,     99,     99,     99,     99,
        24,     26,     56,     99,     99,     99,     99,     99,
        47,     66,     99,     99,     99,     99,     99,     99,
        99,     99,     99,     99,     99,     99,     99,     99,
        99,     99,     99,     99,     99,     99,     99,     99,
        99,     99,     99,     99,     99,     99,     99,     99,
        99,     99,     99,     99,     99,     99,     99,     99
};

static const Q_LIST_ENTRY Inter_coeffsV1[64] =
{
        12, 16,  16,  16,  20,  20,  20,  20,
        16,  16,  16,  16,  20,  20,  20,  20,
        16,  16,  16,  16,  22,  22,  22,  22,
        16,  16,  16,  16,  22,  22,  22,  22,
        20,  20,  22,  22,  24,  24,  24,  24,
        20,  20,  22,  22,  24,  24,  24,  24,
        20,  20,  22,  22,  24,  24,  24,  24,
        20,  20,  22,  22,  24,  24,  24,  24
};

#else /* these are the old VP3 values: */

static const Q_LIST_ENTRY Y_coeffsV1[64] ={
  16,  11,  10,  16,  24,  40,  51,  61,
  12,  12,  14,  19,  26,  58,  60,  55,
  14,  13,  16,  24,  40,  57,  69,  56,
  14,  17,  22,  29,  51,  87,  80,  62,
  18,  22,  37,  58,  68, 109, 103,  77,
  24,  35,  55,  64,  81, 104, 113,  92,
  49,  64,  78,  87, 103, 121, 120, 101,
  72,  92,  95,  98, 112, 100, 103,  99
};

static const Q_LIST_ENTRY UV_coeffsV1[64] ={
  17,   18,     24,     47,     99,     99,     99,     99,
  18,   21,     26,     66,     99,     99,     99,     99,
  24,   26,     56,     99,     99,     99,     99,     99,
  47,   66,     99,     99,     99,     99,     99,     99,
  99,   99,     99,     99,     99,     99,     99,     99,
  99,   99,     99,     99,     99,     99,     99,     99,
  99,   99,     99,     99,     99,     99,     99,     99,
  99,   99,     99,     99,     99,     99,     99,     99
};

static const Q_LIST_ENTRY Inter_coeffsV1[64] ={
  16,  16,  16,  20,  24,  28,  32,  40,
  16,  16,  20,  24,  28,  32,  40,  48,
  16,  20,  24,  28,  32,  40,  48,  64,
  20,  24,  28,  32,  40,  48,  64,  64,
  24,  28,  32,  40,  48,  64,  64,  64,
  28,  32,  40,  48,  64,  64,  64,  96,
  32,  40,  48,  64,  64,  64,  96,  128,
  40,  48,  64,  64,  64,  96,  128, 128
};

#endif

static int _ilog(unsigned int v){
  int ret=0;
  while(v){
    ret++;
    v>>=1;
  }
  return(ret);
}

void WriteQTables(PB_INSTANCE *pbi,oggpack_buffer* opb) {
  int x, bits;
  bits=10;
  oggpackB_write(opb, bits-1, 4);
  for(x=0; x<64; x++) {
    oggpackB_write(opb, pbi->QThreshTable[x],bits);
  }
  oggpackB_write(opb, bits-1, 4);
  for(x=0; x<64; x++) {
    oggpackB_write(opb, pbi->DcScaleFactorTable[x],bits);
  }
  oggpackB_write(opb, 3 - 1, 9); /* number of base matricies */
  for(x=0; x<64; x++) {
    oggpackB_write(opb, pbi->Y_coeffs[x],8);
  }
  for(x=0; x<64; x++) {
    oggpackB_write(opb, pbi->U_coeffs[x],8);
  }
  for(x=0; x<64; x++) {
    oggpackB_write(opb, pbi->InterY_coeffs[x],8);
  }
  /* table mapping */
  oggpackB_write(opb, 0, 2);  /* matrix 0 for intra Y */
  oggpackB_write(opb, 62, 6); /* used for every q */
  oggpackB_write(opb, 0, 2);
  oggpackB_write(opb, 1, 1);  /* next range is explicit */
  oggpackB_write(opb, 1, 2);  /* matrix 1 for intra U */
  oggpackB_write(opb, 62, 6);
  oggpackB_write(opb, 1, 2);
  oggpackB_write(opb, 0, 1);  /* intra V is the same */
  oggpackB_write(opb, 1, 1);  /* next range is explicit */
  oggpackB_write(opb, 2, 2);  /* matrix 2 for inter Y */
  oggpackB_write(opb, 62, 6);
  oggpackB_write(opb, 2, 2);
  oggpackB_write(opb, 0, 2);  /* inter U the same */
  oggpackB_write(opb, 0, 2);  /* inter V the same */
}

static int _read_qtable_range(codec_setup_info *ci, oggpack_buffer* opb,
         int N, int type) 
{
  int index, range;
  int qi = 0;
  int count = 0;
  qmat_range_table table[65];

  theora_read(opb,_ilog(N-1),&index); /* qi=0 index */
  table[count].startqi = 0;
  table[count++].qmat = ci->qmats + index * Q_TABLE_SIZE;
  while(qi<63) {
    theora_read(opb,_ilog(62-qi),&range); /* range to next code q matrix */
    range++;
    if(range<=0) return OC_BADHEADER;
    qi+=range;
    theora_read(opb,_ilog(N-1),&index); /* next index */
    table[count].startqi = qi;
    table[count++].qmat = ci->qmats + index * Q_TABLE_SIZE;
  }

  ci->range_table[type] = _ogg_malloc(count * sizeof(qmat_range_table));
  if (ci->range_table[type] != NULL) {
    memcpy(ci->range_table[type], table, count * sizeof(qmat_range_table)); 
    return 0;
  }
  
  return OC_FAULT; /* allocation failed */
}

int ReadQTables(codec_setup_info *ci, oggpack_buffer* opb) {
  long bits,value;
  int x,y, N;

  /* AC scale table */
  theora_read(opb,4,&bits); bits++;
  for(x=0; x<Q_TABLE_SIZE; x++) {
    theora_read(opb,bits,&value);
    if(bits<0)return OC_BADHEADER;
    ci->QThreshTable[x]=value;
  }
  /* DC scale table */
  theora_read(opb,4,&bits); bits++;
  for(x=0; x<Q_TABLE_SIZE; x++) {
    theora_read(opb,bits,&value);
    if(bits<0)return OC_BADHEADER;
    ci->DcScaleFactorTable[x]=(Q_LIST_ENTRY)value;
  }
  /* base matricies */
  theora_read(opb,9,&N); N++;
  ci->qmats=_ogg_malloc(N*64*sizeof(Q_LIST_ENTRY));
  ci->MaxQMatrixIndex = N;
  for(y=0; y<N; y++) {
    for(x=0; x<64; x++) {
      theora_read(opb,8,&value);
      if(bits<0)return OC_BADHEADER;
      ci->qmats[(y<<6)+x]=(Q_LIST_ENTRY)value;
    }
  }
  /* table mapping */
  for(x=0; x<6; x++) {
    ci->range_table[x] = NULL;
  }
  {
    int flag, ret;
    /* intra Y */
    if((ret=_read_qtable_range(ci,opb,N,0))<0) return ret;
    /* intra U */
    theora_read(opb,1,&flag);
    if(flag<0) return OC_BADHEADER;
    if(flag) {
      /* explicitly coded */
      if((ret=_read_qtable_range(ci,opb,N,1))<0) return ret;
    } else {
      /* same as previous */
    }
    /* intra V */
    theora_read(opb,1,&flag);
    if(flag<0) return OC_BADHEADER;
    if(flag) {
      /* explicitly coded */
      if((ret=_read_qtable_range(ci,opb,N,2))<0) return ret;
    } else {
       /* same as previous */
    }
    /* inter Y */
    theora_read(opb,1,&flag);
    if(flag<0) return OC_BADHEADER;
    if(flag) {
      /* explicitly coded */
      if((ret=_read_qtable_range(ci,opb,N,3))<0) return ret;
    } else {
      theora_read(opb,1,&flag);
      if(flag<0) return OC_BADHEADER;
      if(flag) {
        /* same as corresponding intra */
      } else {
        /* same as previous */
      }
    }
    /* inter U */
    theora_read(opb,1,&flag);
    if(flag<0) return OC_BADHEADER;
    if(flag) {
      /* explicitly coded */
      if((ret=_read_qtable_range(ci,opb,N,4))<0) return ret;
    } else {
      theora_read(opb,1,&flag);
      if(flag<0) return OC_BADHEADER;
      if(flag) {
        /* same as corresponding intra */
      } else {
        /* same as previous */
      }
    }
    /* inter V */
    theora_read(opb,1,&flag);
    if(flag<0) return OC_BADHEADER;
    if(flag) {
      /* explicitly coded */
      if((ret=_read_qtable_range(ci,opb,N,5))<0) return ret;
    } else {
      theora_read(opb,1,&flag);