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internal.c

/********************************************************************
 *                                                                  *
 * 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) 2002-2007                *
 * by the Xiph.Org Foundation http://www.xiph.org/                  *
 *                                                                  *
 ********************************************************************

  function:
    last mod: $Id: internal.c 13911 2007-09-28 01:39:26Z tterribe $

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

#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include "../internal.h"
#include "idct.h"



/*A map from the index in the zig zag scan to the coefficient number in a
   block.
  All zig zag indices beyond 63 are sent to coefficient 64, so that zero runs
   past the end of a block in bogus streams get mapped to a known location.*/
const int OC_FZIG_ZAG[128]={
   0, 1, 8,16, 9, 2, 3,10,
  17,24,32,25,18,11, 4, 5,
  12,19,26,33,40,48,41,34,
  27,20,13, 6, 7,14,21,28,
  35,42,49,56,57,50,43,36,
  29,22,15,23,30,37,44,51,
  58,59,52,45,38,31,39,46,
  53,60,61,54,47,55,62,63,
  64,64,64,64,64,64,64,64,
  64,64,64,64,64,64,64,64,
  64,64,64,64,64,64,64,64,
  64,64,64,64,64,64,64,64,
  64,64,64,64,64,64,64,64,
  64,64,64,64,64,64,64,64,
  64,64,64,64,64,64,64,64,
  64,64,64,64,64,64,64,64
};

/*A map from the coefficient number in a block to its index in the zig zag
   scan.*/
const int OC_IZIG_ZAG[64]={
   0, 1, 5, 6,14,15,27,28,
   2, 4, 7,13,16,26,29,42,
   3, 8,12,17,25,30,41,43,
   9,11,18,24,31,40,44,53,
  10,19,23,32,39,45,52,54,
  20,22,33,38,46,51,55,60,
  21,34,37,47,50,56,59,61,
  35,36,48,49,57,58,62,63
};

/*The predictor frame to use for each macro block mode.*/
const int OC_FRAME_FOR_MODE[8]={
  /*OC_MODE_INTRA*/
  OC_FRAME_SELF,
  /*OC_MODE_INTER_NOMV*/
  OC_FRAME_PREV,
  /*OC_MODE_INTER_MV*/
  OC_FRAME_PREV,
  /*OC_MODE_INTER_MV_LAST*/
  OC_FRAME_PREV,
  /*OC_MODE_INTER_MV_LAST2*/
  OC_FRAME_PREV,
  /*OC_MODE_INTER_MV_FOUR*/
  OC_FRAME_PREV,
  /*OC_MODE_GOLDEN*/
  OC_FRAME_GOLD,
  /*OC_MODE_GOLDEN_MV*/
  OC_FRAME_GOLD,
};

/*A map from physical macro block ordering to bitstream macro block
   ordering within a super block.*/
const int OC_MB_MAP[2][2]={{0,3},{1,2}};

/*A list of the indices in the oc_mb.map array that can be valid for each of
   the various chroma decimation types.*/
const int OC_MB_MAP_IDXS[TH_PF_NFORMATS][12]={
  {0,1,2,3,4,8},
  {0,1,2,3,4,5,8,9},
  {0,1,2,3,4,6,8,10},
  {0,1,2,3,4,5,6,7,8,9,10,11}
};

/*The number of indices in the oc_mb.map array that can be valid for each of
   the various chroma decimation types.*/
const int OC_MB_MAP_NIDXS[TH_PF_NFORMATS]={6,8,8,12};

/*The number of extra bits that are coded with each of the DCT tokens.
  Each DCT token has some fixed number of additional bits (possibly 0) stored
   after the token itself, containing, for example, coefficient magnitude,
   sign bits, etc.*/
const int OC_DCT_TOKEN_EXTRA_BITS[TH_NDCT_TOKENS]={
  0,0,0,2,3,4,12,3,6,
  0,0,0,0,
  1,1,1,1,2,3,4,5,6,10,
  1,1,1,1,1,3,4,
  2,3
};



int oc_ilog(unsigned _v){
  int ret;
  for(ret=0;_v;ret++)_v>>=1;
  return ret;
}



/*Determines the number of blocks or coefficients to be skipped for a given
   token value.
  _token:      The token value to skip.
  _extra_bits: The extra bits attached to this token.
  Return: A positive value indicates that number of coefficients are to be
           skipped in the current block.
          Otherwise, the negative of the return value indicates that number of
           blocks are to be ended.*/
typedef int (*oc_token_skip_func)(int _token,int _extra_bits);

/*Handles the simple end of block tokens.*/
static int oc_token_skip_eob(int _token,int _extra_bits){
  static const int NBLOCKS_ADJUST[OC_NDCT_EOB_TOKEN_MAX]={1,2,3,4,8,16,0};
  return -_extra_bits-NBLOCKS_ADJUST[_token];
}

/*The last EOB token has a special case, where an EOB run of size zero ends all
   the remaining blocks in the frame.*/
static int oc_token_skip_eob6(int _token,int _extra_bits){
  if(!_extra_bits)return -INT_MAX;
  return -_extra_bits;
}

/*Handles the pure zero run tokens.*/
static int oc_token_skip_zrl(int _token,int _extra_bits){
  return _extra_bits+1;
}

/*Handles a normal coefficient value token.*/
static int oc_token_skip_val(void){
  return 1;
}

/*Handles a category 1A zero run/coefficient value combo token.*/
static int oc_token_skip_run_cat1a(int _token){
  return _token-OC_DCT_RUN_CAT1A+2;
}

/*Handles category 1b and 2 zero run/coefficient value combo tokens.*/
static int oc_token_skip_run(int _token,int _extra_bits){
  static const int NCOEFFS_ADJUST[OC_NDCT_RUN_MAX-OC_DCT_RUN_CAT1B]={
    7,11,2,3
  };
  static const int NCOEFFS_MASK[OC_NDCT_RUN_MAX-OC_DCT_RUN_CAT1B]={
    3,7,0,1
  };
  _token-=OC_DCT_RUN_CAT1B;
  return (_extra_bits&NCOEFFS_MASK[_token])+NCOEFFS_ADJUST[_token];
}

/*A jump table for computing the number of coefficients or blocks to skip for
   a given token value.
  This reduces all the conditional branches, etc., needed to parse these token
   values down to one indirect jump.*/
static const oc_token_skip_func OC_TOKEN_SKIP_TABLE[TH_NDCT_TOKENS]={
  oc_token_skip_eob,
  oc_token_skip_eob,
  oc_token_skip_eob,
  oc_token_skip_eob,
  oc_token_skip_eob,
  oc_token_skip_eob,
  oc_token_skip_eob6,
  oc_token_skip_zrl,
  oc_token_skip_zrl,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_val,
  (oc_token_skip_func)oc_token_skip_run_cat1a,
  (oc_token_skip_func)oc_token_skip_run_cat1a,
  (oc_token_skip_func)oc_token_skip_run_cat1a,
  (oc_token_skip_func)oc_token_skip_run_cat1a,
  (oc_token_skip_func)oc_token_skip_run_cat1a,
  oc_token_skip_run,
  oc_token_skip_run,
  oc_token_skip_run,
  oc_token_skip_run
};

/*Determines the number of blocks or coefficients to be skipped for a given
   token value.
  _token:      The token value to skip.
  _extra_bits: The extra bits attached to this token.
  Return: A positive value indicates that number of coefficients are to be
           skipped in the current block.
          Otherwise, the negative of the return value indicates that number of
           blocks are to be ended.
          0 will never be returned, so that at least one coefficient in one
           block will always be decoded for every token.*/
int oc_dct_token_skip(int _token,int _extra_bits){
  return (*OC_TOKEN_SKIP_TABLE[_token])(_token,_extra_bits);
}


/*The function used to fill in the chroma plane motion vectors for a macro
   block when 4 different motion vectors are specified in the luma plane.
  This version is for use with chroma decimated in the X and Y directions.
  _cbmvs: The chroma block-level motion vectors to fill in.
  _lbmvs: The luma block-level motion vectors.*/
static void oc_set_chroma_mvs00(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
  int dx;
  int dy;
  dx=_lbmvs[0][0]+_lbmvs[1][0]+_lbmvs[2][0]+_lbmvs[3][0];
  dy=_lbmvs[0][1]+_lbmvs[1][1]+_lbmvs[2][1]+_lbmvs[3][1];
  _cbmvs[0][0]=(signed char)OC_DIV_ROUND_POW2(dx,2,2);
  _cbmvs[0][1]=(signed char)OC_DIV_ROUND_POW2(dy,2,2);
}

/*The function used to fill in the chroma plane motion vectors for a macro
   block when 4 different motion vectors are specified in the luma plane.
  This version is for use with chroma decimated in the Y direction.
  _cbmvs: The chroma block-level motion vectors to fill in.
  _lbmvs: The luma block-level motion vectors.*/
static void oc_set_chroma_mvs01(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
  int dx;
  int dy;
  dx=_lbmvs[0][0]+_lbmvs[2][0];
  dy=_lbmvs[0][1]+_lbmvs[2][1];
  _cbmvs[0][0]=(signed char)OC_DIV_ROUND_POW2(dx,1,1);
  _cbmvs[0][1]=(signed char)OC_DIV_ROUND_POW2(dy,1,1);
  dx=_lbmvs[1][0]+_lbmvs[3][0];
  dy=_lbmvs[1][1]+_lbmvs[3][1];
  _cbmvs[1][0]=(signed char)OC_DIV_ROUND_POW2(dx,1,1);
  _cbmvs[1][1]=(signed char)OC_DIV_ROUND_POW2(dy,1,1);
}

/*The function used to fill in the chroma plane motion vectors for a macro
   block when 4 different motion vectors are specified in the luma plane.
  This version is for use with chroma decimated in the X direction.
  _cbmvs: The chroma block-level motion vectors to fill in.
  _lbmvs: The luma block-level motion vectors.*/
static void oc_set_chroma_mvs10(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
  int dx;
  int dy;
  dx=_lbmvs[0][0]+_lbmvs[1][0];
  dy=_lbmvs[0][1]+_lbmvs[1][1];
  _cbmvs[0][0]=(signed char)OC_DIV_ROUND_POW2(dx,1,1);
  _cbmvs[0][1]=(signed char)OC_DIV_ROUND_POW2(dy,1,1);
  dx=_lbmvs[2][0]+_lbmvs[3][0];
  dy=_lbmvs[2][1]+_lbmvs[3][1];
  _cbmvs[2][0]=(signed char)OC_DIV_ROUND_POW2(dx,1,1);
  _cbmvs[2][1]=(signed char)OC_DIV_ROUND_POW2(dy,1,1);
}

/*The function used to fill in the chroma plane motion vectors for a macro
   block when 4 different motion vectors are specified in the luma plane.
  This version is for use with no chroma decimation.
  _cbmvs: The chroma block-level motion vectors to fill in.
  _lmbmv: The luma macro-block level motion vector to fill in for use in
           prediction.
  _lbmvs: The luma block-level motion vectors.*/
static void oc_set_chroma_mvs11(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
  memcpy(_cbmvs,_lbmvs,4*sizeof(_lbmvs[0]));
}

/*A table of functions used to fill in the chroma plane motion vectors for a
   macro block when 4 different motion vectors are specified in the luma
   plane.*/
const oc_set_chroma_mvs_func OC_SET_CHROMA_MVS_TABLE[TH_PF_NFORMATS]={
  (oc_set_chroma_mvs_func)oc_set_chroma_mvs00,
  (oc_set_chroma_mvs_func)oc_set_chroma_mvs01,
  (oc_set_chroma_mvs_func)oc_set_chroma_mvs10,
  (oc_set_chroma_mvs_func)oc_set_chroma_mvs11
};



void **oc_malloc_2d(size_t _height,size_t _width,size_t _sz){
  size_t  rowsz;
  size_t  colsz;
  size_t  datsz;
  char   *ret;
  colsz=_height*sizeof(void *);
  rowsz=_sz*_width;
  datsz=rowsz*_height;
  /*Alloc array and row pointers.*/
  ret=(char *)_ogg_malloc(datsz+colsz);
  /*Initialize the array.*/
  if(ret!=NULL){
    size_t   i;
    void   **p;
    char    *datptr;
    p=(void **)ret;
    i=_height;
    for(datptr=ret+colsz;i-->0;p++,datptr+=rowsz)*p=(void *)datptr;
  }
  return (void **)ret;
}

void **oc_calloc_2d(size_t _height,size_t _width,size_t _sz){
  size_t  colsz;
  size_t  rowsz;
  size_t  datsz;
  char   *ret;
  colsz=_height*sizeof(void *);
  rowsz=_sz*_width;
  datsz=rowsz*_height;
  /*Alloc array and row pointers.*/
  ret=(char *)_ogg_calloc(datsz+colsz,1);
  /*Initialize the array.*/
  if(ret!=NULL){
    size_t   i;
    void   **p;
    char    *datptr;
    p=(void **)ret;
    i=_height;
    for(datptr=ret+colsz;i-->0;p++,datptr+=rowsz)*p=(void *)datptr;
  }
  return (void **)ret;
}

void oc_free_2d(void *_ptr){
  _ogg_free(_ptr);
}

/*Fills in a Y'CbCr buffer with a pointer to the image data in the first
   buffer, but with the opposite vertical orientation.
  _dst: The destination buffer.
        This can be the same as _src.
  _src: The source buffer.*/
void oc_ycbcr_buffer_flip(th_ycbcr_buffer _dst,
 const th_ycbcr_buffer _src){
  int pli;
  for(pli=0;pli<3;pli++){
    _dst[pli].width=_src[pli].width;
    _dst[pli].height=_src[pli].height;
    _dst[pli].ystride=-_src[pli].ystride;
    _dst[pli].data=_src[pli].data+(1-_dst[pli].height)*_dst[pli].ystride;
  }
}

00362 const char *th_version_string(void){
  return OC_VENDOR_STRING;
}

00366 ogg_uint32_t th_version_number(void){
  return (TH_VERSION_MAJOR<<16)+(TH_VERSION_MINOR<<8)+(TH_VERSION_SUB);
}

/*Determines the packet type.
  Note that this correctly interprets a 0-byte packet as a video data packet.
  Return: 1 for a header packet, 0 for a data packet.*/
00373 int th_packet_isheader(ogg_packet *_op){
  return _op->bytes>0?_op->packet[0]>>7:0;
}

/*Determines the frame type of a video data packet.
  Note that this correctly interprets a 0-byte packet as a delta frame.
  Return: 1 for a key frame, 0 for a delta frame, and -1 for a header
           packet.*/
00381 int th_packet_iskeyframe(ogg_packet *_op){
  return _op->bytes<=0?0:_op->packet[0]&0x80?-1:!(_op->packet[0]&0x40);
}


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