git.sesse.net Git - ffmpeg/blob - libavcodec/h263dec.c

   1 /*
   2  * H263 decoder
   3  * Copyright (c) 2001 Fabrice Bellard.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 #include "avcodec.h"
  20 #include "dsputil.h"
  21 #include "mpegvideo.h"
  22
  23 //#define DEBUG
  24 //#define PRINT_FRAME_TIME
  25 #ifdef PRINT_FRAME_TIME
  26 static inline long long rdtsc()
  27 {
  28         long long l;
  29         asm volatile(   "rdtsc\n\t"
  30                 : "=A" (l)
  31         );
  32 //      printf("%d\n", int(l/1000));
  33         return l;
  34 }
  35 #endif
  36
  37 static int h263_decode_init(AVCodecContext *avctx)
  38 {
  39     MpegEncContext *s = avctx->priv_data;
  40
  41     s->avctx = avctx;
  42     s->out_format = FMT_H263;
  43
  44     s->width = avctx->width;
  45     s->height = avctx->height;
  46     s->workaround_bugs= avctx->workaround_bugs;
  47
  48     /* select sub codec */
  49     switch(avctx->codec->id) {
  50     case CODEC_ID_H263:
  51         s->gob_number = 0;
  52         s->first_slice_line = 0;
  53         break;
  54     case CODEC_ID_MPEG4:
  55         s->time_increment_bits = 4; /* default value for broken headers */
  56         s->h263_pred = 1;
  57         s->has_b_frames = 1; //default, might be overriden in the vol header during header parsing
  58         break;
  59     case CODEC_ID_MSMPEG4V1:
  60         s->h263_msmpeg4 = 1;
  61         s->h263_pred = 1;
  62         s->msmpeg4_version=1;
  63         break;
  64     case CODEC_ID_MSMPEG4V2:
  65         s->h263_msmpeg4 = 1;
  66         s->h263_pred = 1;
  67         s->msmpeg4_version=2;
  68         break;
  69     case CODEC_ID_MSMPEG4V3:
  70         s->h263_msmpeg4 = 1;
  71         s->h263_pred = 1;
  72         s->msmpeg4_version=3;
  73         break;
  74     case CODEC_ID_WMV1:
  75         s->h263_msmpeg4 = 1;
  76         s->h263_pred = 1;
  77         s->msmpeg4_version=4;
  78         break;
  79     case CODEC_ID_WMV2:
  80         s->h263_msmpeg4 = 1;
  81         s->h263_pred = 1;
  82         s->msmpeg4_version=5;
  83         break;
  84     case CODEC_ID_H263I:
  85         s->h263_intel = 1;
  86         break;
  87     default:
  88         return -1;
  89     }
  90     s->codec_id= avctx->codec->id;
  91
  92     /* for h263, we allocate the images after having read the header */
  93     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
  94         if (MPV_common_init(s) < 0)
  95             return -1;
  96
  97     if (s->h263_msmpeg4)
  98         ff_msmpeg4_decode_init(s);
  99     else
 100         h263_decode_init_vlc(s);
 101
 102     return 0;
 103 }
 104
 105 static int h263_decode_end(AVCodecContext *avctx)
 106 {
 107     MpegEncContext *s = avctx->priv_data;
 108
 109     MPV_common_end(s);
 110     return 0;
 111 }
 112
 113 /**
 114  * retunrs the number of bytes consumed for building the current frame
 115  */
 116 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 117     int pos= (get_bits_count(&s->gb)+7)>>3;
 118
 119     if(s->divx_version>=500){
 120         //we would have to scan through the whole buf to handle the weird reordering ...
 121         return buf_size;
 122     }else{
 123         if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
 124         if(pos+10>buf_size) pos=buf_size; // oops ;)
 125
 126         return pos;
 127     }
 128 }
 129
 130 static int h263_decode_frame(AVCodecContext *avctx,
 131                              void *data, int *data_size,
 132                              UINT8 *buf, int buf_size)
 133 {
 134     MpegEncContext *s = avctx->priv_data;
 135     int ret;
 136     AVPicture *pict = data;
 137 #ifdef PRINT_FRAME_TIME
 138 uint64_t time= rdtsc();
 139 #endif
 140 #ifdef DEBUG
 141     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
 142     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 143 #endif
 144
 145     s->hurry_up= avctx->hurry_up;
 146     s->error_resilience= avctx->error_resilience;
 147
 148     s->workaround_bugs= avctx->workaround_bugs;
 149     if(s->avctx->fourcc == ff_get_fourcc("XVIX") && s->workaround_bugs==0)
 150         s->workaround_bugs=2;
 151
 152     s->flags= avctx->flags;
 153
 154     *data_size = 0;
 155
 156    /* no supplementary picture */
 157     if (buf_size == 0) {
 158         return 0;
 159     }
 160
 161     if(s->bitstream_buffer_size && buf_size<20){ //divx 5.01+ frame reorder
 162         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size);
 163     }else
 164         init_get_bits(&s->gb, buf, buf_size);
 165     s->bitstream_buffer_size=0;
 166
 167     if (!s->context_initialized) {
 168         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 169             return -1;
 170     }
 171
 172     /* let's go :-) */
 173     if (s->h263_msmpeg4) {
 174         ret = msmpeg4_decode_picture_header(s);
 175     } else if (s->h263_pred) {
 176         ret = mpeg4_decode_picture_header(s);
 177         s->has_b_frames= !s->low_delay;
 178     } else if (s->h263_intel) {
 179         ret = intel_h263_decode_picture_header(s);
 180     } else {
 181         ret = h263_decode_picture_header(s);
 182     }
 183     avctx->has_b_frames= s->has_b_frames;
 184 #if 0 // dump bits per frame / qp / complexity
 185 {
 186     static FILE *f=NULL;
 187     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 188     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 189 }
 190 #endif
 191
 192         /* After H263 & mpeg4 header decode we have the height, width,*/
 193         /* and other parameters. So then we could init the picture   */
 194         /* FIXME: By the way H263 decoder is evolving it should have */
 195         /* an H263EncContext                                         */
 196     if (   s->width != avctx->width || s->height != avctx->height
 197         || avctx->aspect_ratio_info != s->aspect_ratio_info
 198         || avctx->aspected_width != s->aspected_width
 199         || avctx->aspected_height != s->aspected_height) {
 200         /* H.263 could change picture size any time */
 201         MPV_common_end(s);
 202         s->context_initialized=0;
 203     }
 204     if (!s->context_initialized) {
 205         avctx->width = s->width;
 206         avctx->height = s->height;
 207         avctx->aspect_ratio_info= s->aspect_ratio_info;
 208         if (s->aspect_ratio_info == FF_ASPECT_EXTENDED)
 209         {
 210             avctx->aspected_width = s->aspected_width;
 211             avctx->aspected_height = s->aspected_height;
 212         }
 213         if (MPV_common_init(s) < 0)
 214             return -1;
 215     }
 216
 217     if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
 218     /* skip if the header was thrashed */
 219     if (ret < 0){
 220         fprintf(stderr, "header damaged\n");
 221         return -1;
 222     }
 223     /* skip b frames if we dont have reference frames */
 224     if(s->num_available_buffers<2 && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 225     /* skip b frames if we are in a hurry */
 226     if(s->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 227
 228     if(s->next_p_frame_damaged){
 229         if(s->pict_type==B_TYPE)
 230             return get_consumed_bytes(s, buf_size);
 231         else
 232             s->next_p_frame_damaged=0;
 233     }
 234
 235     MPV_frame_start(s, avctx);
 236
 237 #ifdef DEBUG
 238     printf("qscale=%d\n", s->qscale);
 239 #endif
 240
 241     /* init resync/ error resilience specific variables */
 242     s->next_resync_qscale= s->qscale;
 243     s->next_resync_gb= s->gb;
 244     if(s->resync_marker) s->mb_num_left= 0;
 245     else                 s->mb_num_left= s->mb_num;
 246
 247     /* decode each macroblock */
 248     s->block_wrap[0]=
 249     s->block_wrap[1]=
 250     s->block_wrap[2]=
 251     s->block_wrap[3]= s->mb_width*2 + 2;
 252     s->block_wrap[4]=
 253     s->block_wrap[5]= s->mb_width + 2;
 254     for(s->mb_y=0; s->mb_y < s->mb_height; s->mb_y++) {
 255         /* Check for GOB headers on H.263 */
 256         /* FIXME: In the future H.263+ will have intra prediction */
 257         /* and we are gonna need another way to detect MPEG4      */
 258         if (s->mb_y && !s->h263_pred) {
 259             s->first_slice_line = h263_decode_gob_header(s);
 260         }
 261
 262         if(s->msmpeg4_version==1){
 263             s->last_dc[0]=
 264             s->last_dc[1]=
 265             s->last_dc[2]= 128;
 266         }
 267
 268         s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 269         s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 270
 271         s->block_index[0]= s->block_wrap[0]*(s->mb_y*2 + 1) - 1;
 272         s->block_index[1]= s->block_wrap[0]*(s->mb_y*2 + 1);
 273         s->block_index[2]= s->block_wrap[0]*(s->mb_y*2 + 2) - 1;
 274         s->block_index[3]= s->block_wrap[0]*(s->mb_y*2 + 2);
 275         s->block_index[4]= s->block_wrap[4]*(s->mb_y + 1)                    + s->block_wrap[0]*(s->mb_height*2 + 2);
 276         s->block_index[5]= s->block_wrap[4]*(s->mb_y + 1 + s->mb_height + 2) + s->block_wrap[0]*(s->mb_height*2 + 2);
 277         for(s->mb_x=0; s->mb_x < s->mb_width; s->mb_x++) {
 278             s->block_index[0]+=2;
 279             s->block_index[1]+=2;
 280             s->block_index[2]+=2;
 281             s->block_index[3]+=2;
 282             s->block_index[4]++;
 283             s->block_index[5]++;
 284 #ifdef DEBUG
 285             printf("**mb x=%d y=%d\n", s->mb_x, s->mb_y);
 286 #endif
 287
 288             if(s->resync_marker){
 289                 if(s->mb_num_left<=0){
 290                     /* except the first block */
 291                     if(s->mb_x!=0 || s->mb_y!=0){
 292                         /* did we miss the next resync marker without noticing an error yet */
 293                         if(((get_bits_count(&s->gb)+8)&(~7)) != s->next_resync_pos && s->decoding_error==0){
 294                             fprintf(stderr, "slice end missmatch x:%d y:%d %d %d\n",
 295                                     s->mb_x, s->mb_y, get_bits_count(&s->gb), s->next_resync_pos);
 296                             ff_conceal_past_errors(s, 1);
 297                         }
 298                     }
 299                     s->qscale= s->next_resync_qscale;
 300                     s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 301                     s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 302
 303                     s->gb= s->next_resync_gb;
 304                     s->resync_mb_x= s->mb_x; //we know that the marker is here cuz mb_num_left was the distance to it
 305                     s->resync_mb_y= s->mb_y;
 306                     s->first_slice_line=1;
 307
 308                     if(s->codec_id==CODEC_ID_MPEG4){
 309                         ff_mpeg4_clean_buffers(s);
 310                         ff_mpeg4_resync(s);
 311                     }
 312                 }
 313
 314                 if(   s->resync_mb_x==s->mb_x
 315                    && s->resync_mb_y==s->mb_y && s->decoding_error!=0){
 316                     fprintf(stderr, "resynced at %d %d\n", s->mb_x, s->mb_y);
 317                     s->decoding_error= 0;
 318                 }
 319             }
 320
 321             //fprintf(stderr,"\nFrame: %d\tMB: %d",avctx->frame_number, (s->mb_y * s->mb_width) + s->mb_x);
 322             /* DCT & quantize */
 323             if(s->decoding_error!=DECODING_DESYNC){
 324                 int last_error= s->decoding_error;
 325                 clear_blocks(s->block[0]);
 326
 327                 s->mv_dir = MV_DIR_FORWARD;
 328                 s->mv_type = MV_TYPE_16X16;
 329                 if (s->h263_msmpeg4) {
 330                     if (msmpeg4_decode_mb(s, s->block) < 0) {
 331                         fprintf(stderr,"Error at MB: %d\n", (s->mb_y * s->mb_width) + s->mb_x);
 332                         s->decoding_error=DECODING_DESYNC;
 333                     }
 334                 } else {
 335                     if (h263_decode_mb(s, s->block) < 0) {
 336                         fprintf(stderr,"Error at MB: %d\n", (s->mb_y * s->mb_width) + s->mb_x);
 337                         s->decoding_error=DECODING_DESYNC;
 338                     }
 339                 }
 340
 341                 if(s->decoding_error!=last_error){
 342                     ff_conceal_past_errors(s, 0);
 343                 }
 344             }
 345
 346             /* conceal errors */
 347             if(    s->decoding_error==DECODING_DESYNC
 348                || (s->decoding_error==DECODING_ACDC_LOST && s->mb_intra)){
 349                 s->mv_dir = MV_DIR_FORWARD;
 350                 s->mv_type = MV_TYPE_16X16;
 351                 s->mb_skiped=0;
 352                 s->mb_intra=0;
 353                 s->mv[0][0][0]=0; //FIXME this is not optimal
 354                 s->mv[0][0][1]=0;
 355                 clear_blocks(s->block[0]);
 356             }else if(s->decoding_error && !s->mb_intra){
 357                 clear_blocks(s->block[0]);
 358             }
 359             //FIXME remove AC for intra
 360
 361             MPV_decode_mb(s, s->block);
 362
 363             s->mb_num_left--;
 364         }
 365         if (    avctx->draw_horiz_band
 366             && (s->num_available_buffers>=1 || (!s->has_b_frames)) ) {
 367             UINT8 *src_ptr[3];
 368             int y, h, offset;
 369             y = s->mb_y * 16;
 370             h = s->height - y;
 371             if (h > 16)
 372                 h = 16;
 373
 374             if(s->pict_type==B_TYPE)
 375                 offset = 0;
 376             else
 377                 offset = y * s->linesize;
 378
 379             if(s->pict_type==B_TYPE || (!s->has_b_frames)){
 380                 src_ptr[0] = s->current_picture[0] + offset;
 381                 src_ptr[1] = s->current_picture[1] + (offset >> 2);
 382                 src_ptr[2] = s->current_picture[2] + (offset >> 2);
 383             } else {
 384                 src_ptr[0] = s->last_picture[0] + offset;
 385                 src_ptr[1] = s->last_picture[1] + (offset >> 2);
 386                 src_ptr[2] = s->last_picture[2] + (offset >> 2);
 387             }
 388             avctx->draw_horiz_band(avctx, src_ptr, s->linesize,
 389                                    y, s->width, h);
 390         }
 391     }
 392
 393     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
 394         if(msmpeg4_decode_ext_header(s, buf_size) < 0) return -1;
 395
 396     /* divx 5.01+ bistream reorder stuff */
 397     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_version>=500){
 398         int current_pos= get_bits_count(&s->gb)>>3;
 399
 400         if(   buf_size - current_pos > 5
 401            && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
 402             int i;
 403             int startcode_found=0;
 404             for(i=current_pos; i<buf_size-3; i++){
 405                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 406                     startcode_found=1;
 407                     break;
 408                 }
 409             }
 410             if(startcode_found){
 411                 memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 412                 s->bitstream_buffer_size= buf_size - current_pos;
 413             }
 414         }
 415     }
 416
 417     if(s->bitstream_buffer_size==0 && s->error_resilience>0){
 418         int left= s->gb.size*8 - get_bits_count(&s->gb);
 419         int max_extra=8;
 420
 421         if(s->codec_id==CODEC_ID_MPEG4) max_extra+=32;
 422
 423         if(left>max_extra){
 424             fprintf(stderr, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 425             if(s->decoding_error==0)
 426                 ff_conceal_past_errors(s, 1);
 427         }
 428         if(left<0){
 429             fprintf(stderr, "overreading %d bits\n", -left);
 430             if(s->decoding_error==0)
 431                 ff_conceal_past_errors(s, 1);
 432         }
 433     }
 434
 435     MPV_frame_end(s);
 436 #if 0 //dirty show MVs, we should export the MV tables and write a filter to show them
 437 {
 438   int mb_y;
 439   s->has_b_frames=1;
 440   for(mb_y=0; mb_y<s->mb_height; mb_y++){
 441     int mb_x;
 442     int y= mb_y*16 + 8;
 443     for(mb_x=0; mb_x<s->mb_width; mb_x++){
 444       int x= mb_x*16 + 8;
 445       uint8_t *ptr= s->last_picture[0];
 446       int xy= 1 + mb_x*2 + (mb_y*2 + 1)*(s->mb_width*2 + 2);
 447       int mx= (s->motion_val[xy][0]>>1) + x;
 448       int my= (s->motion_val[xy][1]>>1) + y;
 449       int i;
 450       int max;
 451
 452       if(mx<0) mx=0;
 453       if(my<0) my=0;
 454       if(mx>=s->width)  mx= s->width -1;
 455       if(my>=s->height) my= s->height-1;
 456       max= ABS(mx-x);
 457       if(ABS(my-y) > max) max= ABS(my-y);
 458       /* the ugliest linedrawing routine ... */
 459       for(i=0; i<max; i++){
 460         int x1= x + (mx-x)*i/max;
 461         int y1= y + (my-y)*i/max;
 462         ptr[y1*s->linesize + x1]+=100;
 463       }
 464       ptr[y*s->linesize + x]+=100;
 465       s->mbskip_table[mb_x + mb_y*s->mb_width]=0;
 466     }
 467   }
 468
 469 }
 470 #endif
 471     if(s->pict_type==B_TYPE || (!s->has_b_frames)){
 472         pict->data[0] = s->current_picture[0];
 473         pict->data[1] = s->current_picture[1];
 474         pict->data[2] = s->current_picture[2];
 475     } else {
 476         pict->data[0] = s->last_picture[0];
 477         pict->data[1] = s->last_picture[1];
 478         pict->data[2] = s->last_picture[2];
 479     }
 480     pict->linesize[0] = s->linesize;
 481     pict->linesize[1] = s->uvlinesize;
 482     pict->linesize[2] = s->uvlinesize;
 483
 484     avctx->quality = s->qscale;
 485
 486     /* Return the Picture timestamp as the frame number */
 487     /* we substract 1 because it is added on utils.c    */
 488     avctx->frame_number = s->picture_number - 1;
 489
 490     /* dont output the last pic after seeking
 491        note we allready added +1 for the current pix in MPV_frame_end(s) */
 492     if(s->num_available_buffers>=2 || (!s->has_b_frames))
 493         *data_size = sizeof(AVPicture);
 494 #ifdef PRINT_FRAME_TIME
 495 printf("%Ld\n", rdtsc()-time);
 496 #endif
 497     return get_consumed_bytes(s, buf_size);
 498 }
 499
 500 AVCodec mpeg4_decoder = {
 501     "mpeg4",
 502     CODEC_TYPE_VIDEO,
 503     CODEC_ID_MPEG4,
 504     sizeof(MpegEncContext),
 505     h263_decode_init,
 506     NULL,
 507     h263_decode_end,
 508     h263_decode_frame,
 509     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 510 };
 511
 512 AVCodec h263_decoder = {
 513     "h263",
 514     CODEC_TYPE_VIDEO,
 515     CODEC_ID_H263,
 516     sizeof(MpegEncContext),
 517     h263_decode_init,
 518     NULL,
 519     h263_decode_end,
 520     h263_decode_frame,
 521     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 522 };
 523
 524 AVCodec msmpeg4v1_decoder = {
 525     "msmpeg4v1",
 526     CODEC_TYPE_VIDEO,
 527     CODEC_ID_MSMPEG4V1,
 528     sizeof(MpegEncContext),
 529     h263_decode_init,
 530     NULL,
 531     h263_decode_end,
 532     h263_decode_frame,
 533     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 534 };
 535
 536 AVCodec msmpeg4v2_decoder = {
 537     "msmpeg4v2",
 538     CODEC_TYPE_VIDEO,
 539     CODEC_ID_MSMPEG4V2,
 540     sizeof(MpegEncContext),
 541     h263_decode_init,
 542     NULL,
 543     h263_decode_end,
 544     h263_decode_frame,
 545     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 546 };
 547
 548 AVCodec msmpeg4v3_decoder = {
 549     "msmpeg4",
 550     CODEC_TYPE_VIDEO,
 551     CODEC_ID_MSMPEG4V3,
 552     sizeof(MpegEncContext),
 553     h263_decode_init,
 554     NULL,
 555     h263_decode_end,
 556     h263_decode_frame,
 557     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 558 };
 559
 560 AVCodec wmv1_decoder = {
 561     "wmv1",
 562     CODEC_TYPE_VIDEO,
 563     CODEC_ID_WMV1,
 564     sizeof(MpegEncContext),
 565     h263_decode_init,
 566     NULL,
 567     h263_decode_end,
 568     h263_decode_frame,
 569     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 570 };
 571
 572 AVCodec wmv2_decoder = {
 573     "wmv2",
 574     CODEC_TYPE_VIDEO,
 575     CODEC_ID_WMV2,
 576     sizeof(MpegEncContext),
 577     h263_decode_init,
 578     NULL,
 579     h263_decode_end,
 580     h263_decode_frame,
 581     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 582 };
 583
 584 AVCodec h263i_decoder = {
 585     "h263i",
 586     CODEC_TYPE_VIDEO,
 587     CODEC_ID_H263I,
 588     sizeof(MpegEncContext),
 589     h263_decode_init,
 590     NULL,
 591     h263_decode_end,
 592     h263_decode_frame,
 593     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 594 };
 595