theora-exp/lib/internal.c

   1 #include <stdlib.h>
   2 #include <limits.h>
   3 #include <string.h>
   4 #include "internal.h"
   5 #include "idct.h"
   6
   7
   8
   9 /*A map from the index in the zig zag scan to the coefficient number in a
  10    block.
  11   All zig zag indices beyond 63 are sent to coefficient 64, so that zero runs
  12    past the end of a block in bogus streams get mapped to a known location.*/
  13 const int OC_FZIG_ZAG[128]={
  14    0, 1, 8,16, 9, 2, 3,10,
  15   17,24,32,25,18,11, 4, 5,
  16   12,19,26,33,40,48,41,34,
  17   27,20,13, 6, 7,14,21,28,
  18   35,42,49,56,57,50,43,36,
  19   29,22,15,23,30,37,44,51,
  20   58,59,52,45,38,31,39,46,
  21   53,60,61,54,47,55,62,63,
  22   64,64,64,64,64,64,64,64,
  23   64,64,64,64,64,64,64,64,
  24   64,64,64,64,64,64,64,64,
  25   64,64,64,64,64,64,64,64,
  26   64,64,64,64,64,64,64,64,
  27   64,64,64,64,64,64,64,64,
  28   64,64,64,64,64,64,64,64,
  29   64,64,64,64,64,64,64,64
  30 };
  31
  32 /*A map from the coefficient number in a block to its index in the zig zag
  33    scan.*/
  34 const int OC_IZIG_ZAG[64]={
  35    0, 1, 5, 6,14,15,27,28,
  36    2, 4, 7,13,16,26,29,42,
  37    3, 8,12,17,25,30,41,43,
  38    9,11,18,24,31,40,44,53,
  39   10,19,23,32,39,45,52,54,
  40   20,22,33,38,46,51,55,60,
  41   21,34,37,47,50,56,59,61,
  42   35,36,48,49,57,58,62,63
  43 };
  44
  45 /*The predictor frame to use for each macro block mode.*/
  46 const int OC_FRAME_FOR_MODE[8]={
  47   /*OC_MODE_INTRA*/
  48   OC_FRAME_SELF,
  49   /*OC_MODE_INTER_NOMV*/
  50   OC_FRAME_PREV,
  51   /*OC_MODE_INTER_MV*/
  52   OC_FRAME_PREV,
  53   /*OC_MODE_INTER_MV_LAST*/
  54   OC_FRAME_PREV,
  55   /*OC_MODE_INTER_MV_LAST2*/
  56   OC_FRAME_PREV,
  57   /*OC_MODE_INTER_MV_FOUR*/
  58   OC_FRAME_PREV,
  59   /*OC_MODE_GOLDEN*/
  60   OC_FRAME_GOLD,
  61   /*OC_MODE_GOLDEN_MV*/
  62   OC_FRAME_GOLD,
  63 };
  64
  65 /*A map from physical macro block ordering to bitstream macro block
  66    ordering within a super block.*/
  67 const int OC_MB_MAP[2][2]={{0,3},{1,2}};
  68
  69 /*A list of the indices in the oc_mb.map array that can be valid for each of
  70    the various chroma decimation types.*/
  71 const int OC_MB_MAP_IDXS[TH_PF_NFORMATS][12]={
  72   {0,1,2,3,4,8},
  73   {0,1,2,3,4,5,8,9},
  74   {0,1,2,3,4,6,8,10},
  75   {0,1,2,3,4,5,6,7,8,9,10,11}
  76 };
  77
  78 /*The number of indices in the oc_mb.map array that can be valid for each of
  79    the various chroma decimation types.*/
  80 const int OC_MB_MAP_NIDXS[TH_PF_NFORMATS]={6,8,8,12};
  81
  82 /*The number of extra bits that are coded with each of the DCT tokens.
  83   Each DCT token has some fixed number of additional bits (possibly 0) stored
  84    after the token itself, containing, for example, coefficient magnitude,
  85    sign bits, etc.*/
  86 const int OC_DCT_TOKEN_EXTRA_BITS[TH_NDCT_TOKENS]={
  87   0,0,0,2,3,4,12,3,6,
  88   0,0,0,0,
  89   1,1,1,1,2,3,4,5,6,10,
  90   1,1,1,1,1,3,4,
  91   2,3
  92 };
  93
  94
  95
  96 int oc_ilog(unsigned _v){
  97   int ret;
  98   for(ret=0;_v;ret++)_v>>=1;
  99   return ret;
 100 }
 101
 102
 103
 104 /*Determines the number of blocks or coefficients to be skipped for a given
 105    token value.
 106   _token:      The token value to skip.
 107   _extra_bits: The extra bits attached to this token.
 108   Return: A positive value indicates that number of coefficients are to be
 109            skipped in the current block.
 110           Otherwise, the negative of the return value indicates that number of
 111            blocks are to be ended.*/
 112 typedef int (*oc_token_skip_func)(int _token,int _extra_bits);
 113
 114 /*Handles the simple end of block tokens.*/
 115 static int oc_token_skip_eob(int _token,int _extra_bits){
 116   static const int NBLOCKS_ADJUST[OC_NDCT_EOB_TOKEN_MAX]={1,2,3,4,8,16,0};
 117   return -_extra_bits-NBLOCKS_ADJUST[_token];
 118 }
 119
 120 /*The last EOB token has a special case, where an EOB run of size zero ends all
 121    the remaining blocks in the frame.*/
 122 static int oc_token_skip_eob6(int _token,int _extra_bits){
 123   if(!_extra_bits)return -INT_MAX;
 124   return -_extra_bits;
 125 }
 126
 127 /*Handles the pure zero run tokens.*/
 128 static int oc_token_skip_zrl(int _token,int _extra_bits){
 129   return _extra_bits+1;
 130 }
 131
 132 /*Handles a normal coefficient value token.*/
 133 static int oc_token_skip_val(void){
 134   return 1;
 135 }
 136
 137 /*Handles a category 1A zero run/coefficient value combo token.*/
 138 static int oc_token_skip_run_cat1a(int _token){
 139   return _token-OC_DCT_RUN_CAT1A+2;
 140 }
 141
 142 /*Handles category 1b and 2 zero run/coefficient value combo tokens.*/
 143 static int oc_token_skip_run(int _token,int _extra_bits){
 144   static const int NCOEFFS_ADJUST[OC_NDCT_RUN_MAX-OC_DCT_RUN_CAT1B]={
 145     7,11,2,3
 146   };
 147   static const int NCOEFFS_MASK[OC_NDCT_RUN_MAX-OC_DCT_RUN_CAT1B]={
 148     3,7,0,1
 149   };
 150   _token-=OC_DCT_RUN_CAT1B;
 151   return (_extra_bits&NCOEFFS_MASK[_token])+NCOEFFS_ADJUST[_token];
 152 }
 153
 154 /*A jump table for computing the number of coefficients or blocks to skip for
 155    a given token value.
 156   This reduces all the conditional branches, etc., needed to parse these token
 157    values down to one indirect jump.*/
 158 static const oc_token_skip_func OC_TOKEN_SKIP_TABLE[TH_NDCT_TOKENS]={
 159   oc_token_skip_eob,
 160   oc_token_skip_eob,
 161   oc_token_skip_eob,
 162   oc_token_skip_eob,
 163   oc_token_skip_eob,
 164   oc_token_skip_eob,
 165   oc_token_skip_eob6,
 166   oc_token_skip_zrl,
 167   oc_token_skip_zrl,
 168   (oc_token_skip_func)oc_token_skip_val,
 169   (oc_token_skip_func)oc_token_skip_val,
 170   (oc_token_skip_func)oc_token_skip_val,
 171   (oc_token_skip_func)oc_token_skip_val,
 172   (oc_token_skip_func)oc_token_skip_val,
 173   (oc_token_skip_func)oc_token_skip_val,
 174   (oc_token_skip_func)oc_token_skip_val,
 175   (oc_token_skip_func)oc_token_skip_val,
 176   (oc_token_skip_func)oc_token_skip_val,
 177   (oc_token_skip_func)oc_token_skip_val,
 178   (oc_token_skip_func)oc_token_skip_val,
 179   (oc_token_skip_func)oc_token_skip_val,
 180   (oc_token_skip_func)oc_token_skip_val,
 181   (oc_token_skip_func)oc_token_skip_val,
 182   (oc_token_skip_func)oc_token_skip_run_cat1a,
 183   (oc_token_skip_func)oc_token_skip_run_cat1a,
 184   (oc_token_skip_func)oc_token_skip_run_cat1a,
 185   (oc_token_skip_func)oc_token_skip_run_cat1a,
 186   (oc_token_skip_func)oc_token_skip_run_cat1a,
 187   oc_token_skip_run,
 188   oc_token_skip_run,
 189   oc_token_skip_run,
 190   oc_token_skip_run
 191 };
 192
 193 /*Determines the number of blocks or coefficients to be skipped for a given
 194    token value.
 195   _token:      The token value to skip.
 196   _extra_bits: The extra bits attached to this token.
 197   Return: A positive value indicates that number of coefficients are to be
 198            skipped in the current block.
 199           Otherwise, the negative of the return value indicates that number of
 200            blocks are to be ended.
 201           0 will never be returned, so that at least one coefficient in one
 202            block will always be decoded for every token.*/
 203 int oc_dct_token_skip(int _token,int _extra_bits){
 204   return (*OC_TOKEN_SKIP_TABLE[_token])(_token,_extra_bits);
 205 }
 206
 207
 208 /*The function used to fill in the chroma plane motion vectors for a macro
 209    block when 4 different motion vectors are specified in the luma plane.
 210   This version is for use with chroma decimated in the X and Y directions.
 211   _cbmvs: The chroma block-level motion vectors to fill in.
 212   _lbmvs: The luma block-level motion vectors.*/
 213 static void oc_set_chroma_mvs00(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
 214   int dx;
 215   int dy;
 216   dx=_lbmvs[0][0]+_lbmvs[1][0]+_lbmvs[2][0]+_lbmvs[3][0];
 217   dy=_lbmvs[0][1]+_lbmvs[1][1]+_lbmvs[2][1]+_lbmvs[3][1];
 218   _cbmvs[0][0]=(signed char)OC_DIV_ROUND_POW2(dx,2,2);
 219   _cbmvs[0][1]=(signed char)OC_DIV_ROUND_POW2(dy,2,2);
 220 }
 221
 222 /*The function used to fill in the chroma plane motion vectors for a macro
 223    block when 4 different motion vectors are specified in the luma plane.
 224   This version is for use with chroma decimated in the Y direction.
 225   _cbmvs: The chroma block-level motion vectors to fill in.
 226   _lbmvs: The luma block-level motion vectors.*/
 227 static void oc_set_chroma_mvs01(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
 228   int dx;
 229   int dy;
 230   dx=_lbmvs[0][0]+_lbmvs[2][0];
 231   dy=_lbmvs[0][1]+_lbmvs[2][1];
 232   _cbmvs[0][0]=(signed char)OC_DIV_ROUND_POW2(dx,1,1);
 233   _cbmvs[0][1]=(signed char)OC_DIV_ROUND_POW2(dy,1,1);
 234   dx=_lbmvs[1][0]+_lbmvs[3][0];
 235   dy=_lbmvs[1][1]+_lbmvs[3][1];
 236   _cbmvs[1][0]=(signed char)OC_DIV_ROUND_POW2(dx,1,1);
 237   _cbmvs[1][1]=(signed char)OC_DIV_ROUND_POW2(dy,1,1);
 238 }
 239
 240 /*The function used to fill in the chroma plane motion vectors for a macro
 241    block when 4 different motion vectors are specified in the luma plane.
 242   This version is for use with chroma decimated in the X direction.
 243   _cbmvs: The chroma block-level motion vectors to fill in.
 244   _lbmvs: The luma block-level motion vectors.*/
 245 static void oc_set_chroma_mvs10(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
 246   int dx;
 247   int dy;
 248   dx=_lbmvs[0][0]+_lbmvs[1][0];
 249   dy=_lbmvs[0][1]+_lbmvs[1][1];
 250   _cbmvs[0][0]=(signed char)OC_DIV_ROUND_POW2(dx,1,1);
 251   _cbmvs[0][1]=(signed char)OC_DIV_ROUND_POW2(dy,1,1);
 252   dx=_lbmvs[2][0]+_lbmvs[3][0];
 253   dy=_lbmvs[2][1]+_lbmvs[3][1];
 254   _cbmvs[2][0]=(signed char)OC_DIV_ROUND_POW2(dx,1,1);
 255   _cbmvs[2][1]=(signed char)OC_DIV_ROUND_POW2(dy,1,1);
 256 }
 257
 258 /*The function used to fill in the chroma plane motion vectors for a macro
 259    block when 4 different motion vectors are specified in the luma plane.
 260   This version is for use with no chroma decimation.
 261   _cbmvs: The chroma block-level motion vectors to fill in.
 262   _lmbmv: The luma macro-block level motion vector to fill in for use in
 263            prediction.
 264   _lbmvs: The luma block-level motion vectors.*/
 265 static void oc_set_chroma_mvs11(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
 266   memcpy(_cbmvs,_lbmvs,4*sizeof(_lbmvs[0]));
 267 }
 268
 269 /*A table of functions used to fill in the chroma plane motion vectors for a
 270    macro block when 4 different motion vectors are specified in the luma
 271    plane.*/
 272 const oc_set_chroma_mvs_func OC_SET_CHROMA_MVS_TABLE[TH_PF_NFORMATS]={
 273   oc_set_chroma_mvs00,
 274   oc_set_chroma_mvs01,
 275   oc_set_chroma_mvs10,
 276   oc_set_chroma_mvs11
 277 };
 278
 279
 280
 281 void **oc_malloc_2d(size_t _height,size_t _width,size_t _sz){
 282   size_t  rowsz;
 283   size_t  colsz;
 284   size_t  datsz;
 285   char   *ret;
 286   colsz=_height*sizeof(void *);
 287   rowsz=_sz*_width;
 288   datsz=rowsz*_height;
 289   /*Alloc array and row pointers.*/
 290   ret=(char *)_ogg_malloc(datsz+colsz);
 291   /*Initialize the array.*/
 292   if(ret!=NULL){
 293     size_t   i;
 294     void   **p;
 295     char    *datptr;
 296     p=(void **)ret;
 297     i=_height;
 298     for(datptr=ret+colsz;i-->0;p++,datptr+=rowsz)*p=(void *)datptr;
 299   }
 300   return (void **)ret;
 301 }
 302
 303 void **oc_calloc_2d(size_t _height,size_t _width,size_t _sz){
 304   size_t  colsz;
 305   size_t  rowsz;
 306   size_t  datsz;
 307   char   *ret;
 308   colsz=_height*sizeof(void *);
 309   rowsz=_sz*_width;
 310   datsz=rowsz*_height;
 311   /*Alloc array and row pointers.*/
 312   ret=(char *)_ogg_calloc(datsz+colsz,1);
 313   /*Initialize the array.*/
 314   if(ret!=NULL){
 315     size_t   i;
 316     void   **p;
 317     char    *datptr;
 318     p=(void **)ret;
 319     i=_height;
 320     for(datptr=ret+colsz;i-->0;p++,datptr+=rowsz)*p=(void *)datptr;
 321   }
 322   return (void **)ret;
 323 }
 324
 325 void oc_free_2d(void *_ptr){
 326   _ogg_free(_ptr);
 327 }
 328
 329 /*Fills in a Y'CbCr buffer with a pointer to the image data in the first
 330    buffer, but with the opposite vertical orientation.
 331   _dst: The destination buffer.
 332         This can be the same as _src.
 333   _src: The source buffer.*/
 334 void oc_ycbcr_buffer_flip(th_ycbcr_buffer _dst,const th_ycbcr_buffer _src){
 335   int pli;
 336   for(pli=0;pli<3;pli++){
 337     _dst[pli].width=_src[pli].width;
 338     _dst[pli].height=_src[pli].height;
 339     _dst[pli].ystride=-_src[pli].ystride;
 340     _dst[pli].data=_src[pli].data+(1-_dst[pli].height)*_dst[pli].ystride;
 341   }
 342 }
 343
 344 const char *th_version_string(void){
 345   return OC_VENDOR_STRING;
 346 }
 347
 348 ogg_uint32_t th_version_number(void){
 349   return (TH_VERSION_MAJOR<<16)+(TH_VERSION_MINOR<<8)+(TH_VERSION_SUB);
 350 }
 351
 352 /*Determines the packet type.
 353   Note that this correctly interprets a 0-byte packet as a video data packet.
 354   Return: 1 for a header packet, 0 for a data packet.*/
 355 int th_packet_isheader(ogg_packet *_op){
 356   return _op->bytes>0?_op->packet[0]>>7:0;
 357 }
 358
 359 /*Determines the frame type of a video data packet.
 360   Note that this correctly interprets a 0-byte packet as a delta frame.
 361   Return: 1 for a key frame, 0 for a delta frame, and -1 for a header
 362            packet.*/
 363 int th_packet_iskeyframe(ogg_packet *_op){
 364   return _op->bytes<=0?0:_op->packet[0]&0x80?-1:!(_op->packet[0]&0x40);
 365 }