3 * Copyright (c) 2001 Fabrice Bellard
4 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
6 * This file is part of Libav.
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
28 #include "libavutil/cpu.h"
31 #include "error_resilience.h"
32 #include "mpegvideo.h"
34 #include "h263_parser.h"
35 #include "mpeg4video_parser.h"
39 #include "mpeg4video.h"
41 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
43 MpegEncContext *s = avctx->priv_data;
46 s->out_format = FMT_H263;
48 s->width = avctx->coded_width;
49 s->height = avctx->coded_height;
50 s->workaround_bugs= avctx->workaround_bugs;
53 ff_MPV_decode_defaults(s);
55 s->decode_mb= ff_h263_decode_mb;
57 if (avctx->codec->id == AV_CODEC_ID_MSS2)
58 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
60 avctx->pix_fmt = avctx->get_format(avctx, avctx->codec->pix_fmts);
61 s->unrestricted_mv= 1;
63 /* select sub codec */
64 switch(avctx->codec->id) {
65 case AV_CODEC_ID_H263:
66 s->unrestricted_mv= 0;
67 avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
69 case AV_CODEC_ID_MPEG4:
71 case AV_CODEC_ID_MSMPEG4V1:
75 case AV_CODEC_ID_MSMPEG4V2:
79 case AV_CODEC_ID_MSMPEG4V3:
83 case AV_CODEC_ID_WMV1:
87 case AV_CODEC_ID_WMV2:
92 case AV_CODEC_ID_WMV3:
93 case AV_CODEC_ID_VC1IMAGE:
94 case AV_CODEC_ID_WMV3IMAGE:
95 case AV_CODEC_ID_MSS2:
98 avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
100 case AV_CODEC_ID_H263I:
102 case AV_CODEC_ID_FLV1:
108 s->codec_id= avctx->codec->id;
109 avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
111 /* for h263, we allocate the images after having read the header */
112 if (avctx->codec->id != AV_CODEC_ID_H263 && avctx->codec->id != AV_CODEC_ID_MPEG4)
113 if (ff_MPV_common_init(s) < 0)
116 ff_h263_decode_init_vlc();
121 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
123 MpegEncContext *s = avctx->priv_data;
125 ff_MPV_common_end(s);
130 * Return the number of bytes consumed for building the current frame.
132 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
133 int pos= (get_bits_count(&s->gb)+7)>>3;
135 if(s->divx_packed || s->avctx->hwaccel){
136 //we would have to scan through the whole buf to handle the weird reordering ...
138 }else if(s->flags&CODEC_FLAG_TRUNCATED){
139 pos -= s->parse_context.last_index;
140 if(pos<0) pos=0; // padding is not really read so this might be -1
143 if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
144 if(pos+10>buf_size) pos=buf_size; // oops ;)
150 static int decode_slice(MpegEncContext *s){
151 const int part_mask= s->partitioned_frame ? (ER_AC_END|ER_AC_ERROR) : 0x7F;
152 const int mb_size = 16;
153 s->last_resync_gb= s->gb;
154 s->first_slice_line= 1;
156 s->resync_mb_x= s->mb_x;
157 s->resync_mb_y= s->mb_y;
159 ff_set_qscale(s, s->qscale);
161 if (s->avctx->hwaccel) {
162 const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
163 const uint8_t *end = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
164 skip_bits_long(&s->gb, 8*(end - start));
165 return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
168 if(s->partitioned_frame){
169 const int qscale= s->qscale;
171 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
172 if(ff_mpeg4_decode_partitions(s) < 0)
176 /* restore variables which were modified */
177 s->first_slice_line=1;
178 s->mb_x= s->resync_mb_x;
179 s->mb_y= s->resync_mb_y;
180 ff_set_qscale(s, qscale);
183 for(; s->mb_y < s->mb_height; s->mb_y++) {
184 /* per-row end of slice checks */
185 if(s->msmpeg4_version){
186 if(s->resync_mb_y + s->slice_height == s->mb_y){
187 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
193 if(s->msmpeg4_version==1){
199 ff_init_block_index(s);
200 for(; s->mb_x < s->mb_width; s->mb_x++) {
203 ff_update_block_index(s);
205 if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
206 s->first_slice_line=0;
211 s->mv_dir = MV_DIR_FORWARD;
212 s->mv_type = MV_TYPE_16X16;
213 // s->mb_skipped = 0;
214 av_dlog(s, "%d %d %06X\n",
215 ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
216 ret= s->decode_mb(s, s->block);
218 if (s->pict_type!=AV_PICTURE_TYPE_B)
219 ff_h263_update_motion_val(s);
222 const int xy= s->mb_x + s->mb_y*s->mb_stride;
224 ff_MPV_decode_mb(s, s->block);
226 ff_h263_loop_filter(s);
228 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
230 s->padding_bug_score--;
232 if(++s->mb_x >= s->mb_width){
234 ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
235 ff_MPV_report_decode_progress(s);
239 }else if(ret==SLICE_NOEND){
240 av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
241 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x+1, s->mb_y, ER_MB_END&part_mask);
244 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
245 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR&part_mask);
250 ff_MPV_decode_mb(s, s->block);
252 ff_h263_loop_filter(s);
255 ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
256 ff_MPV_report_decode_progress(s);
261 assert(s->mb_x==0 && s->mb_y==s->mb_height);
263 if(s->codec_id==AV_CODEC_ID_MPEG4
264 && (s->workaround_bugs&FF_BUG_AUTODETECT)
265 && get_bits_left(&s->gb) >= 48
266 && show_bits(&s->gb, 24)==0x4010
267 && !s->data_partitioning)
268 s->padding_bug_score+=32;
270 /* try to detect the padding bug */
271 if( s->codec_id==AV_CODEC_ID_MPEG4
272 && (s->workaround_bugs&FF_BUG_AUTODETECT)
273 && get_bits_left(&s->gb) >=0
274 && get_bits_left(&s->gb) < 48
275 // && !s->resync_marker
276 && !s->data_partitioning){
278 const int bits_count= get_bits_count(&s->gb);
279 const int bits_left = s->gb.size_in_bits - bits_count;
282 s->padding_bug_score+=16;
283 } else if(bits_left != 1){
284 int v= show_bits(&s->gb, 8);
285 v|= 0x7F >> (7-(bits_count&7));
287 if(v==0x7F && bits_left<=8)
288 s->padding_bug_score--;
289 else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
290 s->padding_bug_score+= 4;
292 s->padding_bug_score++;
296 if(s->workaround_bugs&FF_BUG_AUTODETECT){
297 if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
298 s->workaround_bugs |= FF_BUG_NO_PADDING;
300 s->workaround_bugs &= ~FF_BUG_NO_PADDING;
303 // handle formats which don't have unique end markers
304 if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
305 int left= get_bits_left(&s->gb);
308 /* no markers in M$ crap */
309 if(s->msmpeg4_version && s->pict_type==AV_PICTURE_TYPE_I)
312 /* buggy padding but the frame should still end approximately at the bitstream end */
313 if((s->workaround_bugs&FF_BUG_NO_PADDING) && (s->err_recognition&AV_EF_BUFFER))
315 else if((s->workaround_bugs&FF_BUG_NO_PADDING))
316 max_extra+= 256*256*256*64;
319 av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
322 av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
324 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
329 av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
330 get_bits_left(&s->gb),
331 show_bits(&s->gb, 24), s->padding_bug_score);
333 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
338 int ff_h263_decode_frame(AVCodecContext *avctx,
339 void *data, int *got_frame,
342 const uint8_t *buf = avpkt->data;
343 int buf_size = avpkt->size;
344 MpegEncContext *s = avctx->priv_data;
346 AVFrame *pict = data;
348 s->flags= avctx->flags;
349 s->flags2= avctx->flags2;
351 /* no supplementary picture */
353 /* special case for last picture */
354 if (s->low_delay==0 && s->next_picture_ptr) {
355 if ((ret = av_frame_ref(pict, &s->next_picture_ptr->f)) < 0)
357 s->next_picture_ptr= NULL;
365 if(s->flags&CODEC_FLAG_TRUNCATED){
368 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
369 next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
370 }else if(CONFIG_H263_DECODER && s->codec_id==AV_CODEC_ID_H263){
371 next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
373 av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
377 if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
384 if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
385 init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
387 init_get_bits(&s->gb, buf, buf_size*8);
388 s->bitstream_buffer_size=0;
390 if (!s->context_initialized) {
391 if (ff_MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
395 /* We need to set current_picture_ptr before reading the header,
396 * otherwise we cannot store anyting in there */
397 if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
398 int i= ff_find_unused_picture(s, 0);
401 s->current_picture_ptr= &s->picture[i];
405 if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
406 ret= ff_wmv2_decode_picture_header(s);
407 } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
408 ret = ff_msmpeg4_decode_picture_header(s);
409 } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
410 if(s->avctx->extradata_size && s->picture_number==0){
413 init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
414 ret = ff_mpeg4_decode_picture_header(s, &gb);
416 ret = ff_mpeg4_decode_picture_header(s, &s->gb);
417 } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {
418 ret = ff_intel_h263_decode_picture_header(s);
419 } else if (CONFIG_FLV_DECODER && s->h263_flv) {
420 ret = ff_flv_decode_picture_header(s);
422 ret = ff_h263_decode_picture_header(s);
425 if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
427 /* skip if the header was thrashed */
429 av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
433 avctx->has_b_frames= !s->low_delay;
435 if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
436 if(s->stream_codec_tag == AV_RL32("XVID") ||
437 s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
438 s->codec_tag == AV_RL32("RMP4") || s->codec_tag == AV_RL32("ZMP4") ||
439 s->codec_tag == AV_RL32("SIPP")
443 if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
444 && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
449 if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
450 if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
451 s->divx_version= 400; //divx 4
454 if(s->xvid_build>=0 && s->divx_version>=0){
459 if(s->workaround_bugs&FF_BUG_AUTODETECT){
460 if(s->codec_tag == AV_RL32("XVIX"))
461 s->workaround_bugs|= FF_BUG_XVID_ILACE;
463 if(s->codec_tag == AV_RL32("UMP4")){
464 s->workaround_bugs|= FF_BUG_UMP4;
467 if(s->divx_version>=500 && s->divx_build<1814){
468 s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
471 if(s->divx_version>502 && s->divx_build<1814){
472 s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
475 if(s->xvid_build<=3U)
476 s->padding_bug_score= 256*256*256*64;
478 if(s->xvid_build<=1U)
479 s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
481 if(s->xvid_build<=12U)
482 s->workaround_bugs|= FF_BUG_EDGE;
484 if(s->xvid_build<=32U)
485 s->workaround_bugs|= FF_BUG_DC_CLIP;
487 #define SET_QPEL_FUNC(postfix1, postfix2) \
488 s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
489 s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
490 s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
492 if(s->lavc_build<4653U)
493 s->workaround_bugs|= FF_BUG_STD_QPEL;
495 if(s->lavc_build<4655U)
496 s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
498 if(s->lavc_build<4670U){
499 s->workaround_bugs|= FF_BUG_EDGE;
502 if(s->lavc_build<=4712U)
503 s->workaround_bugs|= FF_BUG_DC_CLIP;
505 if(s->divx_version>=0)
506 s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
507 if(s->divx_version==501 && s->divx_build==20020416)
508 s->padding_bug_score= 256*256*256*64;
510 if(s->divx_version<500U){
511 s->workaround_bugs|= FF_BUG_EDGE;
514 if(s->divx_version>=0)
515 s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
517 if(s->divx_version==500)
518 s->padding_bug_score= 256*256*256*64;
520 /* very ugly XVID padding bug detection FIXME/XXX solve this differently
521 * Let us hope this at least works.
523 if( s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
524 && s->codec_id==AV_CODEC_ID_MPEG4 && s->vo_type==0)
525 s->workaround_bugs|= FF_BUG_NO_PADDING;
527 if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
528 s->workaround_bugs|= FF_BUG_NO_PADDING;
532 if(s->workaround_bugs& FF_BUG_STD_QPEL){
533 SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
534 SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
535 SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
536 SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
537 SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
538 SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
540 SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
541 SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
542 SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
543 SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
544 SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
545 SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
548 if(avctx->debug & FF_DEBUG_BUGS)
549 av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
550 s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
551 s->divx_packed ? "p" : "");
554 if (s->codec_id == AV_CODEC_ID_MPEG4 && s->xvid_build>=0 && avctx->idct_algo == FF_IDCT_AUTO && (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {
555 avctx->idct_algo= FF_IDCT_XVIDMMX;
556 ff_dct_common_init(s);
561 /* After H263 & mpeg4 header decode we have the height, width,*/
562 /* and other parameters. So then we could init the picture */
563 /* FIXME: By the way H263 decoder is evolving it should have */
564 /* an H263EncContext */
566 if (!avctx->coded_width || !avctx->coded_height) {
567 ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
569 s->parse_context.buffer=0;
570 ff_MPV_common_end(s);
571 s->parse_context= pc;
572 avcodec_set_dimensions(avctx, s->width, s->height);
577 if (s->width != avctx->coded_width ||
578 s->height != avctx->coded_height ||
580 /* H.263 could change picture size any time */
581 s->context_reinit = 0;
583 avcodec_set_dimensions(avctx, s->width, s->height);
585 if ((ret = ff_MPV_common_frame_size_change(s)))
589 if((s->codec_id==AV_CODEC_ID_H263 || s->codec_id==AV_CODEC_ID_H263P || s->codec_id == AV_CODEC_ID_H263I))
590 s->gob_index = ff_h263_get_gob_height(s);
592 // for skipping the frame
593 s->current_picture.f.pict_type = s->pict_type;
594 s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
596 /* skip B-frames if we don't have reference frames */
597 if (s->last_picture_ptr == NULL &&
598 (s->pict_type == AV_PICTURE_TYPE_B || s->droppable))
599 return get_consumed_bytes(s, buf_size);
600 if( (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)
601 || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)
602 || avctx->skip_frame >= AVDISCARD_ALL)
603 return get_consumed_bytes(s, buf_size);
605 if(s->next_p_frame_damaged){
606 if(s->pict_type==AV_PICTURE_TYPE_B)
607 return get_consumed_bytes(s, buf_size);
609 s->next_p_frame_damaged=0;
612 if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){
613 s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
614 s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
616 s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
617 s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
620 if(ff_MPV_frame_start(s, avctx) < 0)
623 if (!s->divx_packed && !avctx->hwaccel)
624 ff_thread_finish_setup(avctx);
626 if (avctx->hwaccel) {
627 if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
631 ff_mpeg_er_frame_start(s);
633 //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
634 //which is not available before ff_MPV_frame_start()
635 if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
636 ret = ff_wmv2_decode_secondary_picture_header(s);
637 if(ret<0) return ret;
638 if(ret==1) goto intrax8_decoded;
641 /* decode each macroblock */
645 ret = decode_slice(s);
646 while(s->mb_y<s->mb_height){
647 if(s->msmpeg4_version){
648 if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_left(&s->gb)<0)
651 int prev_x=s->mb_x, prev_y=s->mb_y;
652 if(ff_h263_resync(s)<0)
654 if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
655 s->er.error_occurred = 1;
658 if(s->msmpeg4_version<4 && s->h263_pred)
659 ff_mpeg4_clean_buffers(s);
661 if (decode_slice(s) < 0) ret = AVERROR_INVALIDDATA;
664 if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)
665 if(!CONFIG_MSMPEG4_DECODER || ff_msmpeg4_decode_ext_header(s, buf_size) < 0){
666 s->er.error_status_table[s->mb_num - 1] = ER_MB_ERROR;
669 assert(s->bitstream_buffer_size==0);
670 /* divx 5.01+ bistream reorder stuff */
671 if(s->codec_id==AV_CODEC_ID_MPEG4 && s->divx_packed){
672 int current_pos= get_bits_count(&s->gb)>>3;
673 int startcode_found=0;
675 if(buf_size - current_pos > 5){
677 for(i=current_pos; i<buf_size-3; i++){
678 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
684 if(s->gb.buffer == s->bitstream_buffer && buf_size>7 && s->xvid_build>=0){ //xvid style
691 &s->bitstream_buffer,
692 &s->allocated_bitstream_buffer_size,
693 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
694 if (!s->bitstream_buffer)
695 return AVERROR(ENOMEM);
696 memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
697 s->bitstream_buffer_size= buf_size - current_pos;
702 ff_er_frame_end(&s->er);
704 if (avctx->hwaccel) {
705 if (avctx->hwaccel->end_frame(avctx) < 0)
711 if (!s->divx_packed && avctx->hwaccel)
712 ff_thread_finish_setup(avctx);
714 assert(s->current_picture.f.pict_type == s->current_picture_ptr->f.pict_type);
715 assert(s->current_picture.f.pict_type == s->pict_type);
716 if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
717 if ((ret = av_frame_ref(pict, &s->current_picture_ptr->f)) < 0)
719 ff_print_debug_info(s, s->current_picture_ptr);
720 } else if (s->last_picture_ptr != NULL) {
721 if ((ret = av_frame_ref(pict, &s->last_picture_ptr->f)) < 0)
723 ff_print_debug_info(s, s->last_picture_ptr);
726 if(s->last_picture_ptr || s->low_delay){
730 return (ret && (avctx->err_recognition & AV_EF_EXPLODE))?ret:get_consumed_bytes(s, buf_size);
733 const enum AVPixelFormat ff_h263_hwaccel_pixfmt_list_420[] = {
735 AV_PIX_FMT_VAAPI_VLD,
744 AVCodec ff_h263_decoder = {
746 .type = AVMEDIA_TYPE_VIDEO,
747 .id = AV_CODEC_ID_H263,
748 .priv_data_size = sizeof(MpegEncContext),
749 .init = ff_h263_decode_init,
750 .close = ff_h263_decode_end,
751 .decode = ff_h263_decode_frame,
752 .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
753 CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
754 .flush = ff_mpeg_flush,
755 .long_name = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
756 .pix_fmts = ff_h263_hwaccel_pixfmt_list_420,