FFmpeg
h263dec.c
Go to the documentation of this file.
1 /*
2  * H.263 decoder
3  * Copyright (c) 2001 Fabrice Bellard
4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg 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.
12  *
13  * FFmpeg 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.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * H.263 decoder.
26  */
27 
28 #define UNCHECKED_BITSTREAM_READER 1
29 
30 #include "config_components.h"
31 
32 #include "avcodec.h"
33 #include "codec_internal.h"
34 #include "decode.h"
35 #include "error_resilience.h"
36 #include "flvdec.h"
37 #include "h263.h"
38 #include "h263dec.h"
39 #include "hwaccel_internal.h"
40 #include "hwconfig.h"
41 #include "mpeg_er.h"
42 #include "mpeg4video.h"
43 #include "mpeg4videodec.h"
44 #include "mpegvideo.h"
45 #include "mpegvideodata.h"
46 #include "mpegvideodec.h"
47 #include "mpegvideo_unquantize.h"
48 #include "msmpeg4dec.h"
49 #include "thread.h"
50 #include "wmv2dec.h"
51 
53 #if CONFIG_H263_VAAPI_HWACCEL || CONFIG_MPEG4_VAAPI_HWACCEL
55 #endif
56 #if CONFIG_MPEG4_NVDEC_HWACCEL
58 #endif
59 #if CONFIG_MPEG4_VDPAU_HWACCEL
61 #endif
62 #if CONFIG_H263_VIDEOTOOLBOX_HWACCEL || CONFIG_MPEG4_VIDEOTOOLBOX_HWACCEL
64 #endif
67 };
68 
70 {
71  /* MPEG-4 Studio Profile only, not supported by hardware */
72  if (avctx->bits_per_raw_sample > 8) {
73  av_assert1(((MpegEncContext *)avctx->priv_data)->studio_profile);
74  return avctx->pix_fmt;
75  }
76 
77  if (CONFIG_GRAY && (avctx->flags & AV_CODEC_FLAG_GRAY)) {
80  return AV_PIX_FMT_GRAY8;
81  }
82 
83  if (avctx->codec_id == AV_CODEC_ID_H263 ||
84  avctx->codec_id == AV_CODEC_ID_H263P ||
85  avctx->codec_id == AV_CODEC_ID_MPEG4)
86  return avctx->pix_fmt = ff_get_format(avctx, h263_hwaccel_pixfmt_list_420);
87 
88  return AV_PIX_FMT_YUV420P;
89 }
90 
92 {
93  H263DecContext *const h = avctx->priv_data;
94  MPVContext *const s = &h->c;
95  MPVUnquantDSPContext unquant_dsp_ctx;
96  int ret;
97 
98  s->out_format = FMT_H263;
99 
100  // set defaults
101  ret = ff_mpv_decode_init(s, avctx);
102  if (ret < 0)
103  return ret;
104 
105  h->decode_mb = ff_h263_decode_mb;
106  s->low_delay = 1;
107 
108  s->y_dc_scale_table =
109  s->c_dc_scale_table = ff_mpeg1_dc_scale_table;
110 
111  ff_mpv_unquantize_init(&unquant_dsp_ctx,
112  avctx->flags & AV_CODEC_FLAG_BITEXACT, 0);
113  // dct_unquantize defaults for H.263;
114  // they might change on a per-frame basis for MPEG-4;
115  // dct_unquantize_inter will be unset for MSMPEG4 codecs later.
116  s->dct_unquantize_intra = unquant_dsp_ctx.dct_unquantize_h263_intra;
117  s->dct_unquantize_inter = unquant_dsp_ctx.dct_unquantize_h263_inter;
118 
119  /* select sub codec */
120  switch (avctx->codec->id) {
121  case AV_CODEC_ID_H263:
122  case AV_CODEC_ID_H263P:
124  h->decode_header = ff_h263_decode_picture_header;
125  break;
126  case AV_CODEC_ID_MPEG4:
127  break;
129  s->h263_pred = 1;
130  s->msmpeg4_version = MSMP4_V1;
131  break;
133  s->h263_pred = 1;
134  s->msmpeg4_version = MSMP4_V2;
135  break;
137  s->h263_pred = 1;
138  s->msmpeg4_version = MSMP4_V3;
139  break;
140  case AV_CODEC_ID_WMV1:
141  s->h263_pred = 1;
142  s->msmpeg4_version = MSMP4_WMV1;
143  break;
144  case AV_CODEC_ID_WMV2:
145  s->h263_pred = 1;
146  s->msmpeg4_version = MSMP4_WMV2;
147  break;
148  case AV_CODEC_ID_RV10:
149  case AV_CODEC_ID_RV20:
150  break;
151 #if CONFIG_H263I_DECODER
152  case AV_CODEC_ID_H263I:
153  h->decode_header = ff_intel_h263_decode_picture_header;
154  break;
155 #endif
156 #if CONFIG_FLV_DECODER
157  case AV_CODEC_ID_FLV1:
158  h->decode_header = ff_flv_decode_picture_header;
159  break;
160 #endif
161  default:
162  av_unreachable("Switch contains a case for every codec using ff_h263_decode_init()");
163  }
164 
165  if (avctx->codec_tag == AV_RL32("L263") || avctx->codec_tag == AV_RL32("S263"))
166  if (avctx->extradata_size == 56 && avctx->extradata[0] == 1)
167  h->ehc_mode = 1;
168 
169  /* for H.263, we allocate the images after having read the header */
170  if (avctx->codec->id != AV_CODEC_ID_H263 &&
171  avctx->codec->id != AV_CODEC_ID_H263P &&
172  avctx->codec->id != AV_CODEC_ID_MPEG4) {
173  avctx->pix_fmt = h263_get_format(avctx);
174  if ((ret = ff_mpv_common_init(s)) < 0)
175  return ret;
176  }
177 
178  ff_h263dsp_init(&s->h263dsp);
180 
181  return 0;
182 }
183 
185 {
186  if (h->c.pict_type != AV_PICTURE_TYPE_B && !h->partitioned_frame && !h->c.er.error_occurred)
187  ff_thread_progress_report(&h->c.cur_pic.ptr->progress, h->c.mb_y);
188 }
189 
190 static int decode_slice(H263DecContext *const h)
191 {
192  const int part_mask = h->partitioned_frame
193  ? (ER_AC_END | ER_AC_ERROR) : 0x7F;
194  const int mb_size = 16 >> h->c.avctx->lowres;
195  int ret;
196 
197  h->last_resync_gb = h->gb;
198  h->c.first_slice_line = 1;
199  h->c.resync_mb_x = h->c.mb_x;
200  h->c.resync_mb_y = h->c.mb_y;
201 
202  ff_set_qscale(&h->c, h->c.qscale);
203 
204  if (h->c.studio_profile) {
206  return ret;
207  }
208 
209  if (h->c.avctx->hwaccel) {
210  const uint8_t *start = h->gb.buffer + get_bits_count(&h->gb) / 8;
211  ret = FF_HW_CALL(h->c.avctx, decode_slice, start,
212  get_bits_bytesize(&h->gb, 0) - get_bits_count(&h->gb) / 8);
213  // ensure we exit decode loop
214  h->c.mb_y = h->c.mb_height;
215  return ret;
216  }
217 
218  if (h->partitioned_frame) {
219  const int qscale = h->c.qscale;
220 
221  if (CONFIG_MPEG4_DECODER && h->c.codec_id == AV_CODEC_ID_MPEG4)
222  if ((ret = ff_mpeg4_decode_partitions(h)) < 0)
223  return ret;
224 
225  /* restore variables which were modified */
226  h->c.first_slice_line = 1;
227  h->c.mb_x = h->c.resync_mb_x;
228  h->c.mb_y = h->c.resync_mb_y;
229  ff_set_qscale(&h->c, qscale);
230  }
231 
232  for (; h->c.mb_y < h->c.mb_height; h->c.mb_y++) {
233  /* per-row end of slice checks */
234  if (h->c.msmpeg4_version != MSMP4_UNUSED) {
235  if (h->c.resync_mb_y + h->slice_height == h->c.mb_y) {
236  ff_er_add_slice(&h->c.er, h->c.resync_mb_x, h->c.resync_mb_y,
237  h->c.mb_x - 1, h->c.mb_y, ER_MB_END);
238 
239  return 0;
240  }
241  }
242 
243  if (h->c.msmpeg4_version == MSMP4_V1) {
244  h->c.last_dc[0] =
245  h->c.last_dc[1] =
246  h->c.last_dc[2] = 128;
247  }
248 
249  ff_init_block_index(&h->c);
250  for (; h->c.mb_x < h->c.mb_width; h->c.mb_x++) {
251  int ret;
252 
253  ff_update_block_index(&h->c, h->c.avctx->bits_per_raw_sample,
254  h->c.avctx->lowres, h->c.chroma_x_shift);
255 
256  if (h->c.resync_mb_x == h->c.mb_x && h->c.resync_mb_y + 1 == h->c.mb_y)
257  h->c.first_slice_line = 0;
258 
259  /* DCT & quantize */
260 
261  h->c.mv_dir = MV_DIR_FORWARD;
262  h->c.mv_type = MV_TYPE_16X16;
263  ff_dlog(h->c.avctx, "%d %06X\n",
264  get_bits_count(&h->gb), show_bits(&h->gb, 24));
265 
266  ff_tlog(NULL, "Decoding MB at %dx%d\n", h->c.mb_x, h->c.mb_y);
267  ret = h->decode_mb(h);
268 
269  if (h->c.h263_pred || h->c.h263_aic) {
270  int mb_xy = h->c.mb_y * h->c.mb_stride + h->c.mb_x;
271  if (!h->c.mb_intra) {
273  } else
274  h->c.mbintra_table[mb_xy] = 1;
275  }
276 
277  if (h->c.pict_type != AV_PICTURE_TYPE_B)
279 
280  if (ret < 0) {
281  const int xy = h->c.mb_x + h->c.mb_y * h->c.mb_stride;
282  if (ret == SLICE_END) {
283  ff_mpv_reconstruct_mb(&h->c, h->block);
284  if (h->loop_filter)
285  ff_h263_loop_filter(&h->c);
286 
287  ff_er_add_slice(&h->c.er, h->c.resync_mb_x, h->c.resync_mb_y,
288  h->c.mb_x, h->c.mb_y, ER_MB_END & part_mask);
289 
290  h->padding_bug_score--;
291 
292  if (++h->c.mb_x >= h->c.mb_width) {
293  h->c.mb_x = 0;
295  ff_mpeg_draw_horiz_band(&h->c, h->c.mb_y * mb_size, mb_size);
296  h->c.mb_y++;
297  }
298  return 0;
299  } else if (ret == SLICE_NOEND) {
300  av_log(h->c.avctx, AV_LOG_ERROR,
301  "Slice mismatch at MB: %d\n", xy);
302  ff_er_add_slice(&h->c.er, h->c.resync_mb_x, h->c.resync_mb_y,
303  h->c.mb_x + 1, h->c.mb_y,
304  ER_MB_END & part_mask);
305  return AVERROR_INVALIDDATA;
306  }
307  av_log(h->c.avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
308  ff_er_add_slice(&h->c.er, h->c.resync_mb_x, h->c.resync_mb_y,
309  h->c.mb_x, h->c.mb_y, ER_MB_ERROR & part_mask);
310 
311  if ((h->c.avctx->err_recognition & AV_EF_IGNORE_ERR) && get_bits_left(&h->gb) > 0)
312  continue;
313  return AVERROR_INVALIDDATA;
314  }
315 
316  ff_mpv_reconstruct_mb(&h->c, h->block);
317  if (h->loop_filter)
318  ff_h263_loop_filter(&h->c);
319  }
320 
322  ff_mpeg_draw_horiz_band(&h->c, h->c.mb_y * mb_size, mb_size);
323 
324  h->c.mb_x = 0;
325  }
326 
327  av_assert1(h->c.mb_x == 0 && h->c.mb_y == h->c.mb_height);
328 
329  // Detect incorrect padding with wrong stuffing codes used by NEC N-02B
330  if (h->c.codec_id == AV_CODEC_ID_MPEG4 &&
331  (h->c.workaround_bugs & FF_BUG_AUTODETECT) &&
332  get_bits_left(&h->gb) >= 48 &&
333  show_bits(&h->gb, 24) == 0x4010 &&
334  !h->data_partitioning)
335  h->padding_bug_score += 32;
336 
337  /* try to detect the padding bug */
338  if (h->c.codec_id == AV_CODEC_ID_MPEG4 &&
339  (h->c.workaround_bugs & FF_BUG_AUTODETECT) &&
340  get_bits_left(&h->gb) >= 0 &&
341  get_bits_left(&h->gb) < 137 &&
342  !h->data_partitioning) {
343  const int bits_count = get_bits_count(&h->gb);
344  const int bits_left = h->gb.size_in_bits - bits_count;
345 
346  if (bits_left == 0) {
347  h->padding_bug_score += 16;
348  } else if (bits_left != 1) {
349  int v = show_bits(&h->gb, 8);
350  v |= 0x7F >> (7 - (bits_count & 7));
351 
352  if (v == 0x7F && bits_left <= 8)
353  h->padding_bug_score--;
354  else if (v == 0x7F && ((get_bits_count(&h->gb) + 8) & 8) &&
355  bits_left <= 16)
356  h->padding_bug_score += 4;
357  else
358  h->padding_bug_score++;
359  }
360  }
361 
362  if (h->c.codec_id == AV_CODEC_ID_H263 &&
363  (h->c.workaround_bugs & FF_BUG_AUTODETECT) &&
364  get_bits_left(&h->gb) >= 8 &&
365  get_bits_left(&h->gb) < 300 &&
366  h->c.pict_type == AV_PICTURE_TYPE_I &&
367  show_bits(&h->gb, 8) == 0 &&
368  !h->data_partitioning) {
369 
370  h->padding_bug_score += 32;
371  }
372 
373  if (h->c.codec_id == AV_CODEC_ID_H263 &&
374  (h->c.workaround_bugs & FF_BUG_AUTODETECT) &&
375  get_bits_left(&h->gb) >= 64 &&
376  AV_RB64(h->gb.buffer + (get_bits_bytesize(&h->gb, 0) - 8)) == 0xCDCDCDCDFC7F0000) {
377 
378  h->padding_bug_score += 32;
379  }
380 
381  if (h->c.workaround_bugs & FF_BUG_AUTODETECT) {
382  if (
383  (h->padding_bug_score > -2 && !h->data_partitioning))
384  h->c.workaround_bugs |= FF_BUG_NO_PADDING;
385  else
386  h->c.workaround_bugs &= ~FF_BUG_NO_PADDING;
387  }
388 
389  // handle formats which don't have unique end markers
390  if (h->c.msmpeg4_version != MSMP4_UNUSED || (h->c.workaround_bugs & FF_BUG_NO_PADDING)) { // FIXME perhaps solve this more cleanly
391  int left = get_bits_left(&h->gb);
392  int max_extra = 7;
393 
394  /* no markers in M$ crap */
395  if (h->c.msmpeg4_version != MSMP4_UNUSED && h->c.pict_type == AV_PICTURE_TYPE_I)
396  max_extra += 17;
397 
398  /* buggy padding but the frame should still end approximately at
399  * the bitstream end */
400  if ((h->c.workaround_bugs & FF_BUG_NO_PADDING) &&
401  (h->c.avctx->err_recognition & (AV_EF_BUFFER|AV_EF_AGGRESSIVE)))
402  max_extra += 48;
403  else if ((h->c.workaround_bugs & FF_BUG_NO_PADDING))
404  max_extra += 256 * 256 * 256 * 64;
405 
406  if (left > max_extra)
407  av_log(h->c.avctx, AV_LOG_ERROR,
408  "discarding %d junk bits at end, next would be %X\n",
409  left, show_bits(&h->gb, 24));
410  else if (left < 0)
411  av_log(h->c.avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
412  else
413  ff_er_add_slice(&h->c.er, h->c.resync_mb_x, h->c.resync_mb_y,
414  h->c.mb_x - 1, h->c.mb_y, ER_MB_END);
415 
416  return 0;
417  }
418 
419  av_log(h->c.avctx, AV_LOG_ERROR,
420  "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
421  get_bits_left(&h->gb), show_bits(&h->gb, 24), h->padding_bug_score);
422 
423  ff_er_add_slice(&h->c.er, h->c.resync_mb_x, h->c.resync_mb_y, h->c.mb_x, h->c.mb_y,
424  ER_MB_END & part_mask);
425 
426  return AVERROR_INVALIDDATA;
427 }
428 
430  int *got_frame, AVPacket *avpkt)
431 {
432  H263DecContext *const h = avctx->priv_data;
433  MPVContext *const s = &h->c;
434  const uint8_t *buf = avpkt->data;
435  int buf_size = avpkt->size;
436  int ret;
437  int slice_ret = 0;
438  int bak_width, bak_height;
439 
440  /* no supplementary picture */
441  if (buf_size == 0) {
442  /* special case for last picture */
443  if ((!h->c.low_delay || h->skipped_last_frame) && h->c.next_pic.ptr) {
444  if ((ret = av_frame_ref(pict, h->c.next_pic.ptr->f)) < 0)
445  return ret;
446  if (h->skipped_last_frame) {
447  /* If the stream ended with an NVOP, we output the last frame
448  * in display order, but with the props from the last input
449  * packet so that the stream's end time is correct. */
450  ret = ff_decode_frame_props(avctx, pict);
451  if (ret < 0)
452  return ret;
453  }
454 
455  ff_mpv_unref_picture(&h->c.next_pic);
456 
457  *got_frame = 1;
458  }
459 
460  return 0;
461  }
462 
463  // h->gb might be overridden in ff_mpeg4_decode_picture_header() below.
464  ret = init_get_bits8(&h->gb, buf, buf_size);
465  if (ret < 0)
466  return ret;
467 
468  bak_width = h->c.width;
469  bak_height = h->c.height;
470 
471  /* let's go :-) */
472  ret = h->decode_header(h);
473  if (ret < 0 || ret == FRAME_SKIPPED) {
474  if ( h->c.width != bak_width
475  || h->c.height != bak_height) {
476  av_log(h->c.avctx, AV_LOG_WARNING, "Reverting picture dimensions change due to header decoding failure\n");
477  h->c.width = bak_width;
478  h->c.height= bak_height;
479 
480  }
481  }
482  if (ret == FRAME_SKIPPED)
483  return buf_size;
484 
485  /* skip if the header was thrashed */
486  if (ret < 0) {
487  av_log(h->c.avctx, AV_LOG_ERROR, "header damaged\n");
488  return ret;
489  }
490 
491  if (!h->c.context_initialized) {
492  avctx->pix_fmt = h263_get_format(avctx);
493  if ((ret = ff_mpv_common_init(s)) < 0)
494  return ret;
495  }
496 
497  avctx->has_b_frames = !h->c.low_delay;
498 
499  if (CONFIG_MPEG4_DECODER && avctx->codec_id == AV_CODEC_ID_MPEG4) {
500  if (h->c.pict_type != AV_PICTURE_TYPE_B && h->c.mb_num/2 > get_bits_left(&h->gb))
501  return AVERROR_INVALIDDATA;
503  if (h->c.studio_profile != (h->c.idsp.idct == NULL))
505  }
506 
507  /* After H.263 & MPEG-4 header decode we have the height, width,
508  * and other parameters. So then we could init the picture. */
509  if (h->c.width != avctx->coded_width ||
510  h->c.height != avctx->coded_height ||
511  h->c.context_reinit) {
512  /* H.263 could change picture size any time */
513  h->c.context_reinit = 0;
514 
515  ret = ff_set_dimensions(avctx, h->c.width, h->c.height);
516  if (ret < 0)
517  return ret;
518 
519  ff_set_sar(avctx, avctx->sample_aspect_ratio);
520 
522  return ret;
523 
524  if (avctx->pix_fmt != h263_get_format(avctx)) {
525  av_log(avctx, AV_LOG_ERROR, "format change not supported\n");
526  avctx->pix_fmt = AV_PIX_FMT_NONE;
527  return AVERROR_UNKNOWN;
528  }
529  }
530 
531  /* skip B-frames if we don't have reference frames */
532  if (!h->c.last_pic.ptr &&
533  (h->c.pict_type == AV_PICTURE_TYPE_B || h->c.droppable))
534  return buf_size;
535  if ((avctx->skip_frame >= AVDISCARD_NONREF &&
536  h->c.pict_type == AV_PICTURE_TYPE_B) ||
537  (avctx->skip_frame >= AVDISCARD_NONKEY &&
538  h->c.pict_type != AV_PICTURE_TYPE_I) ||
539  avctx->skip_frame >= AVDISCARD_ALL)
540  return buf_size;
541 
542  if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
543  return ret;
544 
545  if (!h->divx_packed)
546  ff_thread_finish_setup(avctx);
547 
548  if (avctx->hwaccel) {
549  ret = FF_HW_CALL(avctx, start_frame, NULL,
550  h->gb.buffer, get_bits_bytesize(&h->gb, 0));
551  if (ret < 0 )
552  return ret;
553  }
554 
555  ff_mpv_er_frame_start_ext(s, h->partitioned_frame,
556  s->pp_time, s->pb_time);
557 
558  /* the second part of the wmv2 header contains the MB skip bits which
559  * are stored in current_picture->mb_type which is not available before
560  * ff_mpv_frame_start() */
561 #if CONFIG_WMV2_DECODER
562  if (h->c.msmpeg4_version == MSMP4_WMV2) {
564  if (ret < 0)
565  return ret;
566  if (ret == 1)
567  goto frame_end;
568  }
569 #endif
570 
571  /* decode each macroblock */
572  h->c.mb_x = 0;
573  h->c.mb_y = 0;
574 
575  slice_ret = decode_slice(h);
576  while (h->c.mb_y < h->c.mb_height) {
577  if (h->c.msmpeg4_version != MSMP4_UNUSED) {
578  if (h->slice_height == 0 || h->c.mb_x != 0 || slice_ret < 0 ||
579  (h->c.mb_y % h->slice_height) != 0 || get_bits_left(&h->gb) < 0)
580  break;
581  } else {
582  int prev_x = h->c.mb_x, prev_y = h->c.mb_y;
583  if (ff_h263_resync(h) < 0)
584  break;
585  if (prev_y * h->c.mb_width + prev_x < h->c.mb_y * h->c.mb_width + h->c.mb_x)
586  h->c.er.error_occurred = 1;
587  }
588 
589  if (h->c.msmpeg4_version < MSMP4_WMV1 && h->c.h263_pred)
591 
592  if (decode_slice(h) < 0)
593  slice_ret = AVERROR_INVALIDDATA;
594  }
595 
596  if (h->c.msmpeg4_version != MSMP4_UNUSED && h->c.msmpeg4_version < MSMP4_WMV1 &&
597  h->c.pict_type == AV_PICTURE_TYPE_I)
598  if (!CONFIG_MSMPEG4DEC ||
599  ff_msmpeg4_decode_ext_header(h, buf_size) < 0)
600  h->c.er.error_status_table[h->c.mb_num - 1] = ER_MB_ERROR;
601 
602 frame_end:
603  if (!h->c.studio_profile)
604  ff_er_frame_end(&h->c.er, NULL);
605 
606  if (avctx->hwaccel) {
607  ret = FF_HW_SIMPLE_CALL(avctx, end_frame);
608  if (ret < 0)
609  return ret;
610  }
611 
613 
614  if (CONFIG_MPEG4_DECODER && avctx->codec_id == AV_CODEC_ID_MPEG4)
615  ff_mpeg4_frame_end(avctx, avpkt);
616 
617  av_assert1(h->c.pict_type == h->c.cur_pic.ptr->f->pict_type);
618  if (h->c.pict_type == AV_PICTURE_TYPE_B || h->c.low_delay) {
619  if ((ret = av_frame_ref(pict, h->c.cur_pic.ptr->f)) < 0)
620  return ret;
621  ff_print_debug_info(s, h->c.cur_pic.ptr, pict);
622  ff_mpv_export_qp_table(s, pict, h->c.cur_pic.ptr, FF_MPV_QSCALE_TYPE_MPEG1);
623  } else if (h->c.last_pic.ptr) {
624  if ((ret = av_frame_ref(pict, h->c.last_pic.ptr->f)) < 0)
625  return ret;
626  ff_print_debug_info(s, h->c.last_pic.ptr, pict);
627  ff_mpv_export_qp_table(s, pict, h->c.last_pic.ptr, FF_MPV_QSCALE_TYPE_MPEG1);
628  }
629 
630  if (h->c.last_pic.ptr || h->c.low_delay) {
631  if ( pict->format == AV_PIX_FMT_YUV420P
632  && (h->c.codec_tag == AV_RL32("GEOV") || h->c.codec_tag == AV_RL32("GEOX"))) {
633  for (int p = 0; p < 3; p++) {
634  int h = AV_CEIL_RSHIFT(pict->height, !!p);
635 
636  pict->data[p] += (h - 1) * pict->linesize[p];
637  pict->linesize[p] *= -1;
638  }
639  }
640  *got_frame = 1;
641  }
642 
643  if (slice_ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
644  return slice_ret;
645  else
646  return buf_size;
647 }
648 
650 #if CONFIG_H263_VAAPI_HWACCEL
651  HWACCEL_VAAPI(h263),
652 #endif
653 #if CONFIG_MPEG4_NVDEC_HWACCEL
654  HWACCEL_NVDEC(mpeg4),
655 #endif
656 #if CONFIG_MPEG4_VDPAU_HWACCEL
657  HWACCEL_VDPAU(mpeg4),
658 #endif
659 #if CONFIG_H263_VIDEOTOOLBOX_HWACCEL
660  HWACCEL_VIDEOTOOLBOX(h263),
661 #endif
662  NULL
663 };
664 
666  .p.name = "h263",
667  CODEC_LONG_NAME("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
668  .p.type = AVMEDIA_TYPE_VIDEO,
669  .p.id = AV_CODEC_ID_H263,
670  .priv_data_size = sizeof(H263DecContext),
673  .close = ff_mpv_decode_close,
674  .p.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
676  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP |
678  .flush = ff_mpeg_flush,
679  .p.max_lowres = 3,
680  .hw_configs = h263_hw_config_list,
681 };
682 
684  .p.name = "h263p",
685  CODEC_LONG_NAME("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
686  .p.type = AVMEDIA_TYPE_VIDEO,
687  .p.id = AV_CODEC_ID_H263P,
688  .priv_data_size = sizeof(H263DecContext),
691  .close = ff_mpv_decode_close,
692  .p.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
694  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP |
696  .flush = ff_mpeg_flush,
697  .p.max_lowres = 3,
698  .hw_configs = h263_hw_config_list,
699 };
ff_mpv_common_init
av_cold int ff_mpv_common_init(MpegEncContext *s)
init common structure for both encoder and decoder.
Definition: mpegvideo.c:378
hwconfig.h
mpegvideo_unquantize.h
AVCodecContext::hwaccel
const struct AVHWAccel * hwaccel
Hardware accelerator in use.
Definition: avcodec.h:1405
MV_TYPE_16X16
#define MV_TYPE_16X16
1 vector for the whole mb
Definition: mpegvideo.h:175
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:216
AV_PIX_FMT_CUDA
@ AV_PIX_FMT_CUDA
HW acceleration through CUDA.
Definition: pixfmt.h:260
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:71
AV_EF_EXPLODE
#define AV_EF_EXPLODE
abort decoding on minor error detection
Definition: defs.h:51
ff_thread_progress_report
void ff_thread_progress_report(ThreadProgress *pro, int n)
This function is a no-op in no-op mode; otherwise it notifies other threads that a certain level of p...
Definition: threadprogress.c:53
ff_h263_resync
int ff_h263_resync(H263DecContext *const h)
Decode the group of blocks / video packet header / slice header (MPEG-4 Studio).
Definition: ituh263dec.c:217
h263_hw_config_list
static const AVCodecHWConfigInternal *const h263_hw_config_list[]
Definition: h263dec.c:649
report_decode_progress
static void report_decode_progress(H263DecContext *const h)
Definition: h263dec.c:184
FF_CODEC_CAP_INIT_CLEANUP
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: codec_internal.h:42
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:689
ff_mpv_decode_init
av_cold int ff_mpv_decode_init(MpegEncContext *s, AVCodecContext *avctx)
Initialize the given MpegEncContext for decoding.
Definition: mpegvideo_dec.c:47
ff_get_format
int ff_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
Select the (possibly hardware accelerated) pixel format.
Definition: decode.c:1200
mpeg4videodec.h
AVCodecContext::err_recognition
int err_recognition
Error recognition; may misdetect some more or less valid parts as errors.
Definition: avcodec.h:1398
get_bits_count
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:250
ff_wmv2_decode_secondary_picture_header
int ff_wmv2_decode_secondary_picture_header(H263DecContext *const h)
Definition: wmv2dec.c:236
AV_CODEC_ID_MPEG4
@ AV_CODEC_ID_MPEG4
Definition: codec_id.h:64
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:421
AVPacket::data
uint8_t * data
Definition: packet.h:552
FFCodec
Definition: codec_internal.h:127
FF_HW_SIMPLE_CALL
#define FF_HW_SIMPLE_CALL(avctx, function)
Definition: hwaccel_internal.h:176
ff_er_add_slice
void ff_er_add_slice(ERContext *s, int startx, int starty, int endx, int endy, int status)
Add a slice.
Definition: error_resilience.c:828
ff_init_block_index
void ff_init_block_index(MpegEncContext *s)
Definition: mpegvideo.c:491
mpegvideo.h
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:73
ff_set_dimensions
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:91
thread.h
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:442
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
AVCodecContext::codec
const struct AVCodec * codec
Definition: avcodec.h:440
AVCodecContext::skip_frame
enum AVDiscard skip_frame
Skip decoding for selected frames.
Definition: avcodec.h:1662
AVCodecContext::flags
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:488
MPVUnquantDSPContext::dct_unquantize_h263_intra
void(* dct_unquantize_h263_intra)(struct MpegEncContext *s, int16_t *block, int n, int qscale)
Definition: mpegvideo_unquantize.h:43
HWACCEL_VDPAU
#define HWACCEL_VDPAU(codec)
Definition: hwconfig.h:72
AVCodecContext::coded_height
int coded_height
Definition: avcodec.h:607
AV_CODEC_ID_MSMPEG4V2
@ AV_CODEC_ID_MSMPEG4V2
Definition: codec_id.h:67
ff_h263_update_motion_val
void ff_h263_update_motion_val(MpegEncContext *s)
Definition: h263.c:56
frame_end
static int64_t frame_end(const SyncQueue *sq, SyncQueueFrame frame, int nb_samples)
Compute the end timestamp of a frame.
Definition: sync_queue.c:118
mpegvideodec.h
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:210
h263dec.h
av_cold
#define av_cold
Definition: attributes.h:90
AV_CODEC_ID_H263I
@ AV_CODEC_ID_H263I
Definition: codec_id.h:72
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:539
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:515
AVCodecContext::has_b_frames
int has_b_frames
Size of the frame reordering buffer in the decoder.
Definition: avcodec.h:697
ff_er_frame_end
void ff_er_frame_end(ERContext *s, int *decode_error_flags)
Indicate that a frame has finished decoding and perform error concealment in case it has been enabled...
Definition: error_resilience.c:898
ff_mpeg_flush
av_cold void ff_mpeg_flush(AVCodecContext *avctx)
Definition: mpegvideo_dec.c:411
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:341
s
#define s(width, name)
Definition: cbs_vp9.c:198
AV_CEIL_RSHIFT
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:60
h263_get_format
static enum AVPixelFormat h263_get_format(AVCodecContext *avctx)
Definition: h263dec.c:69
ff_msmpeg4_decode_ext_header
int ff_msmpeg4_decode_ext_header(H263DecContext *const h, int buf_size)
Definition: msmpeg4dec.c:529
FF_BUG_NO_PADDING
#define FF_BUG_NO_PADDING
Definition: avcodec.h:1331
AV_CODEC_ID_WMV2
@ AV_CODEC_ID_WMV2
Definition: codec_id.h:70
ff_mpeg1_dc_scale_table
static const uint8_t *const ff_mpeg1_dc_scale_table
Definition: mpegvideodata.h:32
AV_EF_IGNORE_ERR
#define AV_EF_IGNORE_ERR
ignore errors and continue
Definition: defs.h:53
AVCodecContext::bits_per_raw_sample
int bits_per_raw_sample
Bits per sample/pixel of internal libavcodec pixel/sample format.
Definition: avcodec.h:1553
decode.h
AV_CODEC_ID_MSMPEG4V1
@ AV_CODEC_ID_MSMPEG4V1
Definition: codec_id.h:66
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:73
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:326
AVCodecContext::codec_id
enum AVCodecID codec_id
Definition: avcodec.h:441
FMT_H263
@ FMT_H263
Definition: mpegvideo.h:55
ff_mpv_unref_picture
void ff_mpv_unref_picture(MPVWorkPicture *pic)
Definition: mpegpicture.c:98
AVDISCARD_ALL
@ AVDISCARD_ALL
discard all
Definition: defs.h:229
ff_h263_decode_init_vlc
void ff_h263_decode_init_vlc(void)
Definition: ituh263dec.c:136
ff_h263_decode_mb
int ff_h263_decode_mb(H263DecContext *const h)
Definition: ituh263dec.c:780
ff_mpv_export_qp_table
int ff_mpv_export_qp_table(const MpegEncContext *s, AVFrame *f, const MPVPicture *p, int qp_type)
Definition: mpegvideo_dec.c:372
NULL
#define NULL
Definition: coverity.c:32
bits_left
#define bits_left
Definition: bitstream.h:116
AVCodecContext::color_range
enum AVColorRange color_range
MPEG vs JPEG YUV range.
Definition: avcodec.h:669
ER_AC_ERROR
#define ER_AC_ERROR
Definition: error_resilience.h:29
hwaccel_internal.h
ff_mpv_idct_init
av_cold void ff_mpv_idct_init(MpegEncContext *s)
Definition: mpegvideo.c:96
ff_mpv_decode_close
av_cold int ff_mpv_decode_close(AVCodecContext *avctx)
Definition: mpegvideo_dec.c:125
av_unreachable
#define av_unreachable(msg)
Asserts that are used as compiler optimization hints depending upon ASSERT_LEVEL and NBDEBUG.
Definition: avassert.h:109
ER_MB_ERROR
#define ER_MB_ERROR
Definition: error_resilience.h:36
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:278
ff_set_qscale
void ff_set_qscale(MpegEncContext *s, int qscale)
set qscale and update qscale dependent variables.
Definition: mpegvideo.c:524
ff_set_sar
int ff_set_sar(AVCodecContext *avctx, AVRational sar)
Check that the provided sample aspect ratio is valid and set it on the codec context.
Definition: utils.c:106
ff_h263_decode_frame
int ff_h263_decode_frame(AVCodecContext *avctx, AVFrame *pict, int *got_frame, AVPacket *avpkt)
Definition: h263dec.c:429
ff_mpv_unquantize_init
#define ff_mpv_unquantize_init(s, bitexact, q_scale_type)
Definition: mpegvideo_unquantize.h:50
AV_CODEC_ID_WMV1
@ AV_CODEC_ID_WMV1
Definition: codec_id.h:69
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:81
AVCOL_RANGE_UNSPECIFIED
@ AVCOL_RANGE_UNSPECIFIED
Definition: pixfmt.h:731
FF_MPV_QSCALE_TYPE_MPEG1
#define FF_MPV_QSCALE_TYPE_MPEG1
Definition: mpegvideodec.h:40
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
get_bits_bytesize
static int get_bits_bytesize(const GetBitContext *s, int round_up)
Get the size of the GetBitContext's buffer in bytes.
Definition: get_bits.h:264
ff_dlog
#define ff_dlog(a,...)
Definition: tableprint_vlc.h:28
ff_h263_clean_intra_table_entries
static void ff_h263_clean_intra_table_entries(MpegEncContext *s, int xy)
Definition: h263.h:47
AVDISCARD_NONKEY
@ AVDISCARD_NONKEY
discard all frames except keyframes
Definition: defs.h:228
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:368
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AV_CODEC_FLAG_GRAY
#define AV_CODEC_FLAG_GRAY
Only decode/encode grayscale.
Definition: avcodec.h:302
AVPacket::size
int size
Definition: packet.h:553
ff_mpeg4_clean_buffers
void ff_mpeg4_clean_buffers(MpegEncContext *s)
Definition: mpeg4video.c:44
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:276
codec_internal.h
FRAME_SKIPPED
#define FRAME_SKIPPED
Frame is not coded.
Definition: h263dec.h:87
ff_update_block_index
static void ff_update_block_index(MpegEncContext *s, int bits_per_raw_sample, int lowres, int chroma_x_shift)
Definition: mpegvideo.h:337
AV_CODEC_ID_H263
@ AV_CODEC_ID_H263
Definition: codec_id.h:56
ff_h263dsp_init
av_cold void ff_h263dsp_init(H263DSPContext *ctx)
Definition: h263dsp.c:117
SLICE_NOEND
#define SLICE_NOEND
no end marker or error found but mb count exceeded
Definition: h263dec.h:93
FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM
#define FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM
The decoder extracts and fills its parameters even if the frame is skipped due to the skip_frame sett...
Definition: codec_internal.h:54
ff_mpeg_draw_horiz_band
void ff_mpeg_draw_horiz_band(MpegEncContext *s, int y, int h)
Definition: mpegvideo_dec.c:403
AVFrame::format
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:508
AVCodecHWConfigInternal
Definition: hwconfig.h:25
ff_mpeg4_decode_studio_slice_header
int ff_mpeg4_decode_studio_slice_header(H263DecContext *const h)
Decode the next video packet.
Definition: mpeg4videodec.c:808
ff_mpv_frame_start
int ff_mpv_frame_start(MpegEncContext *s, AVCodecContext *avctx)
generic function called after decoding the header and before a frame is decoded.
Definition: mpegvideo_dec.c:306
ff_h263_decoder
const FFCodec ff_h263_decoder
Definition: h263dec.c:665
mpegvideodata.h
msmpeg4dec.h
flvdec.h
HWACCEL_NVDEC
#define HWACCEL_NVDEC(codec)
Definition: hwconfig.h:68
AV_PIX_FMT_VAAPI
@ AV_PIX_FMT_VAAPI
Hardware acceleration through VA-API, data[3] contains a VASurfaceID.
Definition: pixfmt.h:126
AVCodec::id
enum AVCodecID id
Definition: codec.h:186
AV_PIX_FMT_VDPAU
@ AV_PIX_FMT_VDPAU
HW acceleration through VDPAU, Picture.data[3] contains a VdpVideoSurface.
Definition: pixfmt.h:194
AV_PIX_FMT_VIDEOTOOLBOX
@ AV_PIX_FMT_VIDEOTOOLBOX
hardware decoding through Videotoolbox
Definition: pixfmt.h:305
ff_print_debug_info
void ff_print_debug_info(const MpegEncContext *s, const MPVPicture *p, AVFrame *pict)
Definition: mpegvideo_dec.c:365
AV_CODEC_ID_RV10
@ AV_CODEC_ID_RV10
Definition: codec_id.h:57
MPVUnquantDSPContext::dct_unquantize_h263_inter
void(* dct_unquantize_h263_inter)(struct MpegEncContext *s, int16_t *block, int n, int qscale)
Definition: mpegvideo_unquantize.h:45
ff_h263p_decoder
const FFCodec ff_h263p_decoder
Definition: h263dec.c:683
AVCodecContext::extradata
uint8_t * extradata
Out-of-band global headers that may be used by some codecs.
Definition: avcodec.h:514
show_bits
static unsigned int show_bits(GetBitContext *s, int n)
Show 1-25 bits.
Definition: get_bits.h:369
ff_intel_h263_decode_picture_header
int ff_intel_h263_decode_picture_header(H263DecContext *const h)
Definition: intelh263dec.c:29
av_assert1
#define av_assert1(cond)
assert() equivalent, that does not lie in speed critical code.
Definition: avassert.h:57
FF_BUG_AUTODETECT
#define FF_BUG_AUTODETECT
autodetection
Definition: avcodec.h:1328
AV_CODEC_ID_RV20
@ AV_CODEC_ID_RV20
Definition: codec_id.h:58
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:179
ff_h263_decode_init
av_cold int ff_h263_decode_init(AVCodecContext *avctx)
Definition: h263dec.c:91
AVCodecContext::chroma_sample_location
enum AVChromaLocation chroma_sample_location
This defines the location of chroma samples.
Definition: avcodec.h:676
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:631
AVCOL_RANGE_MPEG
@ AVCOL_RANGE_MPEG
Narrow or limited range content.
Definition: pixfmt.h:748
HWACCEL_VIDEOTOOLBOX
#define HWACCEL_VIDEOTOOLBOX(codec)
Definition: hwconfig.h:74
avcodec.h
ret
ret
Definition: filter_design.txt:187
AV_EF_AGGRESSIVE
#define AV_EF_AGGRESSIVE
consider things that a sane encoder/muxer should not do as an error
Definition: defs.h:56
wmv2dec.h
ff_mpv_er_frame_start_ext
static void ff_mpv_er_frame_start_ext(MPVContext *const s, int partitioned_frame, uint16_t pp_time, uint16_t pb_time)
Definition: mpeg_er.h:27
ff_thread_finish_setup
the pkt_dts and pkt_pts fields in AVFrame will work as usual Restrictions on codec whose streams don t reset across will not work because their bitstreams cannot be decoded in parallel *The contents of buffers must not be read before as well as code calling up to before the decode process starts Call ff_thread_finish_setup() afterwards. If some code can 't be moved
ff_h263_loop_filter
void ff_h263_loop_filter(MpegEncContext *s)
Definition: h263.c:97
left
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2] ... the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so ...,+,-,+,-,+,+,-,+,-,+,... hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32 - hcoeff[1] - hcoeff[2] - ... a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2} an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||......... intra?||||:Block01 :yes no||||:Block02 :....... ..........||||:Block03 ::y DC ::ref index:||||:Block04 ::cb DC ::motion x :||||......... :cr DC ::motion y :||||....... ..........|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------ ------------ ------------|||Y subbands||Cb subbands||Cr subbands||||--- ---||--- ---||--- ---|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------ ------------ ------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction ------------|\ Dequantization ------------------- \||Reference frames|\ IDWT|------- -------|Motion \|||Frame 0||Frame 1||Compensation . OBMC v -------|------- -------|--------------. \------> Frame n output Frame Frame<----------------------------------/|...|------------------- Range Coder:============Binary Range Coder:------------------- The implemented range coder is an adapted version based upon "Range encoding: an algorithm for removing redundancy from a digitised message." by G. N. N. Martin. The symbols encoded by the Snow range coder are bits(0|1). The associated probabilities are not fix but change depending on the symbol mix seen so far. bit seen|new state ---------+----------------------------------------------- 0|256 - state_transition_table[256 - old_state];1|state_transition_table[old_state];state_transition_table={ 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:------------------------- FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1. the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled left
Definition: snow.txt:386
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
H263DecContext
Definition: h263dec.h:43
ff_decode_frame_props
int ff_decode_frame_props(AVCodecContext *avctx, AVFrame *frame)
Set various frame properties from the codec context / packet data.
Definition: decode.c:1481
AVCodecContext
main external API structure.
Definition: avcodec.h:431
ff_mpeg4_decode_partitions
int ff_mpeg4_decode_partitions(H263DecContext *const h)
Decode the first and second partition.
Definition: mpeg4videodec.c:1316
AVFrame::height
int height
Definition: frame.h:493
AV_CODEC_ID_H263P
@ AV_CODEC_ID_H263P
Definition: codec_id.h:71
AV_PICTURE_TYPE_B
@ AV_PICTURE_TYPE_B
Bi-dir predicted.
Definition: avutil.h:280
mpeg4video.h
AVCHROMA_LOC_CENTER
@ AVCHROMA_LOC_CENTER
MPEG-1 4:2:0, JPEG 4:2:0, H.263 4:2:0.
Definition: pixfmt.h:787
SLICE_END
#define SLICE_END
end marker found
Definition: h261dec.c:42
error_resilience.h
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:72
FF_HW_CALL
#define FF_HW_CALL(avctx, function,...)
Definition: hwaccel_internal.h:173
ff_mpv_frame_end
void ff_mpv_frame_end(MpegEncContext *s)
Definition: mpegvideo_dec.c:357
ff_flv_decode_picture_header
int ff_flv_decode_picture_header(H263DecContext *const h)
Definition: flvdec.c:29
AV_CODEC_CAP_DELAY
#define AV_CODEC_CAP_DELAY
Encoder or decoder requires flushing with NULL input at the end in order to give the complete and cor...
Definition: codec.h:76
ff_mpeg4_workaround_bugs
void ff_mpeg4_workaround_bugs(AVCodecContext *avctx)
Definition: mpeg4videodec.c:3097
AVCodecContext::coded_width
int coded_width
Bitstream width / height, may be different from width/height e.g.
Definition: avcodec.h:607
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:200
ff_mpv_reconstruct_mb
void ff_mpv_reconstruct_mb(MPVContext *s, int16_t block[][64])
Definition: mpegvideo_dec.c:1083
AV_EF_BUFFER
#define AV_EF_BUFFER
detect improper bitstream length
Definition: defs.h:50
AV_CODEC_FLAG_BITEXACT
#define AV_CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:322
ER_MB_END
#define ER_MB_END
Definition: error_resilience.h:37
ff_mpeg4_frame_end
int ff_mpeg4_frame_end(AVCodecContext *avctx, const AVPacket *pkt)
Definition: mpeg4videodec.c:3774
AVCodecContext::codec_tag
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:456
MV_DIR_FORWARD
#define MV_DIR_FORWARD
Definition: mpegvideo.h:171
ff_tlog
#define ff_tlog(a,...)
Definition: tableprint_vlc.h:29
AVPacket
This structure stores compressed data.
Definition: packet.h:529
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:458
HWACCEL_VAAPI
#define HWACCEL_VAAPI(codec)
Definition: hwconfig.h:70
mpeg_er.h
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:466
AV_CODEC_CAP_DRAW_HORIZ_BAND
#define AV_CODEC_CAP_DRAW_HORIZ_BAND
Decoder can use draw_horiz_band callback.
Definition: codec.h:44
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AV_CODEC_ID_MSMPEG4V3
@ AV_CODEC_ID_MSMPEG4V3
Definition: codec_id.h:68
h263_hwaccel_pixfmt_list_420
static enum AVPixelFormat h263_hwaccel_pixfmt_list_420[]
Definition: h263dec.c:52
MPVUnquantDSPContext
Definition: mpegvideo_unquantize.h:34
h
h
Definition: vp9dsp_template.c:2070
ER_AC_END
#define ER_AC_END
Definition: error_resilience.h:32
decode_slice
static int decode_slice(H263DecContext *const h)
Definition: h263dec.c:190
AV_CODEC_ID_FLV1
@ AV_CODEC_ID_FLV1
Definition: codec_id.h:73
AVDISCARD_NONREF
@ AVDISCARD_NONREF
discard all non reference
Definition: defs.h:225
MpegEncContext
MpegEncContext.
Definition: mpegvideo.h:63
AVCodecContext::sample_aspect_ratio
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown) That is the width of a pixel divided by the height of the pixel.
Definition: avcodec.h:616
AV_RB64
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_RB64
Definition: bytestream.h:95
ff_h263_decode_picture_header
int ff_h263_decode_picture_header(H263DecContext *const h)
Definition: ituh263dec.c:1088
ff_mpv_common_frame_size_change
av_cold int ff_mpv_common_frame_size_change(MpegEncContext *s)
Definition: mpegvideo_dec.c:134
h263.h