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1/*
2 * H.26L/H.264/AVC/JVT/14496-10/... parser
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * H.264 / AVC / MPEG-4 part10 parser.
25 * @author Michael Niedermayer <michaelni@gmx.at>
26 */
27
28#define UNCHECKED_BITSTREAM_READER 1
29
30#include <assert.h>
31#include <stdint.h>
32
33#include "libavutil/avutil.h"
34#include "libavutil/error.h"
35#include "libavutil/log.h"
36#include "libavutil/mem.h"
37#include "libavutil/pixfmt.h"
38
39#include "avcodec.h"
40#include "get_bits.h"
41#include "golomb.h"
42#include "h264.h"
43#include "h264_sei.h"
44#include "h264_ps.h"
45#include "h264data.h"
46#include "internal.h"
47#include "mpegutils.h"
48#include "parser.h"
49
50typedef struct H264ParseContext {
51 ParseContext pc;
52 H264ParamSets ps;
53 H264DSPContext h264dsp;
54 H264POCContext poc;
55 H264SEIContext sei;
56 int is_avc;
57 int nal_length_size;
58 int got_first;
59 int picture_structure;
60 uint8_t parse_history[6];
61 int parse_history_count;
62 int parse_last_mb;
63 int64_t reference_dts;
64 int last_frame_num, last_picture_structure;
65} H264ParseContext;
66
67
68static int h264_find_frame_end(H264ParseContext *p, const uint8_t *buf,
69 int buf_size, void *logctx)
70{
71 int i, j;
72 uint32_t state;
73 ParseContext *pc = &p->pc;
74
75 int next_avc = p->is_avc ? 0 : buf_size;
76// mb_addr= pc->mb_addr - 1;
77 state = pc->state;
78 if (state > 13)
79 state = 7;
80
81 if (p->is_avc && !p->nal_length_size)
82 av_log(logctx, AV_LOG_ERROR, "AVC-parser: nal length size invalid\n");
83
84 for (i = 0; i < buf_size; i++) {
85 if (i >= next_avc) {
86 int nalsize = 0;
87 i = next_avc;
88 for (j = 0; j < p->nal_length_size; j++)
89 nalsize = (nalsize << 8) | buf[i++];
90 if (nalsize <= 0 || nalsize > buf_size - i) {
91 av_log(logctx, AV_LOG_ERROR, "AVC-parser: nal size %d remaining %d\n", nalsize, buf_size - i);
92 return buf_size;
93 }
94 next_avc = i + nalsize;
95 state = 5;
96 }
97
98 if (state == 7) {
99 i += p->h264dsp.startcode_find_candidate(buf + i, next_avc - i);
100 if (i < next_avc)
101 state = 2;
102 } else if (state <= 2) {
103 if (buf[i] == 1)
104 state ^= 5; // 2->7, 1->4, 0->5
105 else if (buf[i])
106 state = 7;
107 else
108 state >>= 1; // 2->1, 1->0, 0->0
109 } else if (state <= 5) {
110 int nalu_type = buf[i] & 0x1F;
111 if (nalu_type == H264_NAL_SEI || nalu_type == H264_NAL_SPS ||
112 nalu_type == H264_NAL_PPS || nalu_type == H264_NAL_AUD) {
113 if (pc->frame_start_found) {
114 i++;
115 goto found;
116 }
117 } else if (nalu_type == H264_NAL_SLICE || nalu_type == H264_NAL_DPA ||
118 nalu_type == H264_NAL_IDR_SLICE) {
119 state += 8;
120 continue;
121 }
122 state = 7;
123 } else {
124 p->parse_history[p->parse_history_count++] = buf[i];
125 if (p->parse_history_count > 5) {
126 unsigned int mb, last_mb = p->parse_last_mb;
127 GetBitContext gb;
128
129 init_get_bits(&gb, p->parse_history, 8*p->parse_history_count);
130 p->parse_history_count = 0;
131 mb= get_ue_golomb_long(&gb);
132 p->parse_last_mb = mb;
133 if (pc->frame_start_found) {
134 if (mb <= last_mb)
135 goto found;
136 } else
137 pc->frame_start_found = 1;
138 state = 7;
139 }
140 }
141 }
142 pc->state = state;
143 if (p->is_avc)
144 return next_avc;
145 return END_NOT_FOUND;
146
147found:
148 pc->state = 7;
149 pc->frame_start_found = 0;
150 if (p->is_avc)
151 return next_avc;
152 return i - (state & 5) - 5 * (state > 7);
153}
154
155static int scan_mmco_reset(AVCodecParserContext *s, GetBitContext *gb,
156 void *logctx)
157{
158 H264PredWeightTable pwt;
159 int slice_type_nos = s->pict_type & 3;
160 H264ParseContext *p = s->priv_data;
161 int list_count, ref_count[2];
162
163
164 if (p->ps.pps->redundant_pic_cnt_present)
165 get_ue_golomb(gb); // redundant_pic_count
166
167 if (slice_type_nos == AV_PICTURE_TYPE_B)
168 get_bits1(gb); // direct_spatial_mv_pred
169
170 if (ff_h264_parse_ref_count(&list_count, ref_count, gb, p->ps.pps,
171 slice_type_nos, p->picture_structure, logctx) < 0)
172 return AVERROR_INVALIDDATA;
173
174 if (slice_type_nos != AV_PICTURE_TYPE_I) {
175 int list;
176 for (list = 0; list < list_count; list++) {
177 if (get_bits1(gb)) {
178 int index;
179 for (index = 0; ; index++) {
180 unsigned int reordering_of_pic_nums_idc = get_ue_golomb_31(gb);
181
182 if (reordering_of_pic_nums_idc < 3)
183 get_ue_golomb_long(gb);
184 else if (reordering_of_pic_nums_idc > 3) {
185 av_log(logctx, AV_LOG_ERROR,
186 "illegal reordering_of_pic_nums_idc %d\n",
187 reordering_of_pic_nums_idc);
188 return AVERROR_INVALIDDATA;
189 } else
190 break;
191
192 if (index >= ref_count[list]) {
193 av_log(logctx, AV_LOG_ERROR,
194 "reference count %d overflow\n", index);
195 return AVERROR_INVALIDDATA;
196 }
197 }
198 }
199 }
200 }
201
202 if ((p->ps.pps->weighted_pred && slice_type_nos == AV_PICTURE_TYPE_P) ||
203 (p->ps.pps->weighted_bipred_idc == 1 && slice_type_nos == AV_PICTURE_TYPE_B))
204 ff_h264_pred_weight_table(gb, p->ps.sps, ref_count, slice_type_nos,
205 &pwt, logctx);
206
207 if (get_bits1(gb)) { // adaptive_ref_pic_marking_mode_flag
208 int i;
209 for (i = 0; i < MAX_MMCO_COUNT; i++) {
210 MMCOOpcode opcode = get_ue_golomb_31(gb);
211 if (opcode > (unsigned) MMCO_LONG) {
212 av_log(logctx, AV_LOG_ERROR,
213 "illegal memory management control operation %d\n",
214 opcode);
215 return AVERROR_INVALIDDATA;
216 }
217 if (opcode == MMCO_END)
218 return 0;
219 else if (opcode == MMCO_RESET)
220 return 1;
221
222 if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG)
223 get_ue_golomb_long(gb); // difference_of_pic_nums_minus1
224 if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED ||
225 opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG)
226 get_ue_golomb_31(gb);
227 }
228 }
229
230 return 0;
231}
232
233/**
234 * Parse NAL units of found picture and decode some basic information.
235 *
236 * @param s parser context.
237 * @param avctx codec context.
238 * @param buf buffer with field/frame data.
239 * @param buf_size size of the buffer.
240 */
241static inline int parse_nal_units(AVCodecParserContext *s,
242 AVCodecContext *avctx,
243 const uint8_t * const buf, int buf_size)
244{
245 H264ParseContext *p = s->priv_data;
246 H2645NAL nal = { NULL };
247 int buf_index, next_avc;
248 unsigned int pps_id;
249 unsigned int slice_type;
250 int state = -1, got_reset = 0;
251 int q264 = buf_size >=4 && !memcmp("Q264", buf, 4);
252 int field_poc[2];
253 int ret;
254
255 /* set some sane default values */
256 s->pict_type = AV_PICTURE_TYPE_I;
257 s->key_frame = 0;
258 s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
259
260 ff_h264_sei_uninit(&p->sei);
261 p->sei.frame_packing.frame_packing_arrangement_cancel_flag = -1;
262
263 if (!buf_size)
264 return 0;
265
266 buf_index = 0;
267 next_avc = p->is_avc ? 0 : buf_size;
268 for (;;) {
269 const SPS *sps;
270 int src_length, consumed, nalsize = 0;
271
272 if (buf_index >= next_avc) {
273 nalsize = get_nalsize(p->nal_length_size, buf, buf_size, &buf_index, avctx);
274 if (nalsize < 0)
275 break;
276 next_avc = buf_index + nalsize;
277 } else {
278 buf_index = find_start_code(buf, buf_size, buf_index, next_avc);
279 if (buf_index >= buf_size)
280 break;
281 if (buf_index >= next_avc)
282 continue;
283 }
284 src_length = next_avc - buf_index;
285
286 state = buf[buf_index];
287 switch (state & 0x1f) {
288 case H264_NAL_SLICE:
289 case H264_NAL_IDR_SLICE:
290 // Do not walk the whole buffer just to decode slice header
291 if ((state & 0x1f) == H264_NAL_IDR_SLICE || ((state >> 5) & 0x3) == 0) {
292 /* IDR or disposable slice
293 * No need to decode many bytes because MMCOs shall not be present. */
294 if (src_length > 60)
295 src_length = 60;
296 } else {
297 /* To decode up to MMCOs */
298 if (src_length > 1000)
299 src_length = 1000;
300 }
301 break;
302 }
303 consumed = ff_h2645_extract_rbsp(buf + buf_index, src_length, &nal, 1);
304 if (consumed < 0)
305 break;
306
307 buf_index += consumed;
308
309 ret = init_get_bits8(&nal.gb, nal.data, nal.size);
310 if (ret < 0)
311 goto fail;
312 get_bits1(&nal.gb);
313 nal.ref_idc = get_bits(&nal.gb, 2);
314 nal.type = get_bits(&nal.gb, 5);
315
316 switch (nal.type) {
317 case H264_NAL_SPS:
318 ff_h264_decode_seq_parameter_set(&nal.gb, avctx, &p->ps, 0);
319 break;
320 case H264_NAL_PPS:
321 ff_h264_decode_picture_parameter_set(&nal.gb, avctx, &p->ps,
322 nal.size_bits);
323 break;
324 case H264_NAL_SEI:
325 ff_h264_sei_decode(&p->sei, &nal.gb, &p->ps, avctx);
326 break;
327 case H264_NAL_264_DV_META:
328 /*00 00 00 01 7c 01 19 08
329 nal type = 0x7c & 0x1f;
330 any conflict?
331 */
332 avctx->has_dolby_vision_meta = 1;
333 break;
334 case H264_NAL_264_DV_EL:
335 /*00 00 00 01 7e
336 nal type = 0x7e & 0x1f;
337 any conflict?
338 */
339 avctx->has_dolby_vision_el = 1;
340 break;
341 case H264_NAL_IDR_SLICE:
342 s->key_frame = 1;
343
344 p->poc.prev_frame_num = 0;
345 p->poc.prev_frame_num_offset = 0;
346 p->poc.prev_poc_msb =
347 p->poc.prev_poc_lsb = 0;
348 /* fall through */
349 case H264_NAL_SLICE:
350 get_ue_golomb_long(&nal.gb); // skip first_mb_in_slice
351 slice_type = get_ue_golomb_31(&nal.gb);
352 s->pict_type = ff_h264_golomb_to_pict_type[slice_type % 5];
353 if (p->sei.recovery_point.recovery_frame_cnt >= 0) {
354 /* key frame, since recovery_frame_cnt is set */
355 s->key_frame = 1;
356 }
357 /* set key_frame for I frame*/
358 if (s->pict_type == AV_PICTURE_TYPE_I)
359 s->key_frame = 1;
360 pps_id = get_ue_golomb(&nal.gb);
361 if (pps_id >= MAX_PPS_COUNT) {
362 av_log(avctx, AV_LOG_ERROR,
363 "pps_id %u out of range\n", pps_id);
364 goto fail;
365 }
366 if (!p->ps.pps_list[pps_id]) {
367 av_log(avctx, AV_LOG_ERROR,
368 "non-existing PPS %u referenced\n", pps_id);
369 goto fail;
370 }
371
372 av_buffer_unref(&p->ps.pps_ref);
373 av_buffer_unref(&p->ps.sps_ref);
374 p->ps.pps = NULL;
375 p->ps.sps = NULL;
376 p->ps.pps_ref = av_buffer_ref(p->ps.pps_list[pps_id]);
377 if (!p->ps.pps_ref)
378 goto fail;
379 p->ps.pps = (const PPS*)p->ps.pps_ref->data;
380
381 if (!p->ps.sps_list[p->ps.pps->sps_id]) {
382 av_log(avctx, AV_LOG_ERROR,
383 "non-existing SPS %u referenced\n", p->ps.pps->sps_id);
384 goto fail;
385 }
386
387 p->ps.sps_ref = av_buffer_ref(p->ps.sps_list[p->ps.pps->sps_id]);
388 if (!p->ps.sps_ref)
389 goto fail;
390 p->ps.sps = (const SPS*)p->ps.sps_ref->data;
391
392 sps = p->ps.sps;
393
394 // heuristic to detect non marked keyframes
395 if (p->ps.sps->ref_frame_count <= 1 && p->ps.pps->ref_count[0] <= 1 && s->pict_type == AV_PICTURE_TYPE_I)
396 s->key_frame = 1;
397
398 p->poc.frame_num = get_bits(&nal.gb, sps->log2_max_frame_num);
399
400 s->coded_width = 16 * sps->mb_width;
401 s->coded_height = 16 * sps->mb_height;
402 s->width = s->coded_width - (sps->crop_right + sps->crop_left);
403 s->height = s->coded_height - (sps->crop_top + sps->crop_bottom);
404 if (s->width <= 0 || s->height <= 0) {
405 s->width = s->coded_width;
406 s->height = s->coded_height;
407 }
408
409 switch (sps->bit_depth_luma) {
410 case 9:
411 if (sps->chroma_format_idc == 3) s->format = AV_PIX_FMT_YUV444P9;
412 else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P9;
413 else s->format = AV_PIX_FMT_YUV420P9;
414 break;
415 case 10:
416 if (sps->chroma_format_idc == 3) s->format = AV_PIX_FMT_YUV444P10;
417 else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P10;
418 else s->format = AV_PIX_FMT_YUV420P10;
419 break;
420 case 8:
421 if (sps->chroma_format_idc == 3) s->format = AV_PIX_FMT_YUV444P;
422 else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P;
423 else s->format = AV_PIX_FMT_YUV420P;
424 break;
425 default:
426 s->format = AV_PIX_FMT_NONE;
427 }
428
429 avctx->profile = ff_h264_get_profile(sps);
430 avctx->level = sps->level_idc;
431
432 if (sps->frame_mbs_only_flag) {
433 p->picture_structure = PICT_FRAME;
434 } else {
435 if (get_bits1(&nal.gb)) { // field_pic_flag
436 p->picture_structure = PICT_TOP_FIELD + get_bits1(&nal.gb); // bottom_field_flag
437 } else {
438 p->picture_structure = PICT_FRAME;
439 }
440 }
441
442 if (nal.type == H264_NAL_IDR_SLICE)
443 get_ue_golomb_long(&nal.gb); /* idr_pic_id */
444 if (sps->poc_type == 0) {
445 p->poc.poc_lsb = get_bits(&nal.gb, sps->log2_max_poc_lsb);
446
447 if (p->ps.pps->pic_order_present == 1 &&
448 p->picture_structure == PICT_FRAME)
449 p->poc.delta_poc_bottom = get_se_golomb(&nal.gb);
450 }
451
452 if (sps->poc_type == 1 &&
453 !sps->delta_pic_order_always_zero_flag) {
454 p->poc.delta_poc[0] = get_se_golomb(&nal.gb);
455
456 if (p->ps.pps->pic_order_present == 1 &&
457 p->picture_structure == PICT_FRAME)
458 p->poc.delta_poc[1] = get_se_golomb(&nal.gb);
459 }
460
461 /* Decode POC of this picture.
462 * The prev_ values needed for decoding POC of the next picture are not set here. */
463 field_poc[0] = field_poc[1] = INT_MAX;
464 ff_h264_init_poc(field_poc, &s->output_picture_number, sps,
465 &p->poc, p->picture_structure, nal.ref_idc);
466
467 /* Continue parsing to check if MMCO_RESET is present.
468 * FIXME: MMCO_RESET could appear in non-first slice.
469 * Maybe, we should parse all undisposable non-IDR slice of this
470 * picture until encountering MMCO_RESET in a slice of it. */
471 if (nal.ref_idc && nal.type != H264_NAL_IDR_SLICE) {
472 got_reset = scan_mmco_reset(s, &nal.gb, avctx);
473 if (got_reset < 0)
474 goto fail;
475 }
476
477 /* Set up the prev_ values for decoding POC of the next picture. */
478 p->poc.prev_frame_num = got_reset ? 0 : p->poc.frame_num;
479 p->poc.prev_frame_num_offset = got_reset ? 0 : p->poc.frame_num_offset;
480 if (nal.ref_idc != 0) {
481 if (!got_reset) {
482 p->poc.prev_poc_msb = p->poc.poc_msb;
483 p->poc.prev_poc_lsb = p->poc.poc_lsb;
484 } else {
485 p->poc.prev_poc_msb = 0;
486 p->poc.prev_poc_lsb =
487 p->picture_structure == PICT_BOTTOM_FIELD ? 0 : field_poc[0];
488 }
489 }
490
491 if (sps->pic_struct_present_flag && p->sei.picture_timing.present) {
492 switch (p->sei.picture_timing.pic_struct) {
493 case SEI_PIC_STRUCT_TOP_FIELD:
494 case SEI_PIC_STRUCT_BOTTOM_FIELD:
495 s->repeat_pict = 0;
496 break;
497 case SEI_PIC_STRUCT_FRAME:
498 case SEI_PIC_STRUCT_TOP_BOTTOM:
499 case SEI_PIC_STRUCT_BOTTOM_TOP:
500 s->repeat_pict = 1;
501 break;
502 case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
503 case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
504 s->repeat_pict = 2;
505 break;
506 case SEI_PIC_STRUCT_FRAME_DOUBLING:
507 s->repeat_pict = 3;
508 break;
509 case SEI_PIC_STRUCT_FRAME_TRIPLING:
510 s->repeat_pict = 5;
511 break;
512 default:
513 s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
514 break;
515 }
516 } else {
517 s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
518 }
519
520 if (p->picture_structure == PICT_FRAME) {
521 s->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
522 if (sps->pic_struct_present_flag && p->sei.picture_timing.present) {
523 switch (p->sei.picture_timing.pic_struct) {
524 case SEI_PIC_STRUCT_TOP_BOTTOM:
525 case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
526 s->field_order = AV_FIELD_TT;
527 break;
528 case SEI_PIC_STRUCT_BOTTOM_TOP:
529 case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
530 s->field_order = AV_FIELD_BB;
531 break;
532 default:
533 s->field_order = AV_FIELD_PROGRESSIVE;
534 break;
535 }
536 } else {
537 if (field_poc[0] < field_poc[1])
538 s->field_order = AV_FIELD_TT;
539 else if (field_poc[0] > field_poc[1])
540 s->field_order = AV_FIELD_BB;
541 else
542 s->field_order = AV_FIELD_PROGRESSIVE;
543 }
544 } else {
545 if (p->picture_structure == PICT_TOP_FIELD)
546 s->picture_structure = AV_PICTURE_STRUCTURE_TOP_FIELD;
547 else
548 s->picture_structure = AV_PICTURE_STRUCTURE_BOTTOM_FIELD;
549 if (p->poc.frame_num == p->last_frame_num &&
550 p->last_picture_structure != AV_PICTURE_STRUCTURE_UNKNOWN &&
551 p->last_picture_structure != AV_PICTURE_STRUCTURE_FRAME &&
552 p->last_picture_structure != s->picture_structure) {
553 if (p->last_picture_structure == AV_PICTURE_STRUCTURE_TOP_FIELD)
554 s->field_order = AV_FIELD_TT;
555 else
556 s->field_order = AV_FIELD_BB;
557 } else {
558 s->field_order = AV_FIELD_UNKNOWN;
559 }
560 p->last_picture_structure = s->picture_structure;
561 p->last_frame_num = p->poc.frame_num;
562 }
563
564 av_freep(&nal.rbsp_buffer);
565 return 0; /* no need to evaluate the rest */
566 }
567 }
568 if (q264) {
569 av_freep(&nal.rbsp_buffer);
570 return 0;
571 }
572 /* didn't find a picture! */
573 av_log(avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
574fail:
575 av_freep(&nal.rbsp_buffer);
576 return -1;
577}
578
579static int h264_parse(AVCodecParserContext *s,
580 AVCodecContext *avctx,
581 const uint8_t **poutbuf, int *poutbuf_size,
582 const uint8_t *buf, int buf_size)
583{
584 H264ParseContext *p = s->priv_data;
585 ParseContext *pc = &p->pc;
586 int next;
587
588 if (!p->got_first) {
589 p->got_first = 1;
590 if (avctx->extradata_size) {
591 ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,
592 &p->ps, &p->is_avc, &p->nal_length_size,
593 avctx->err_recognition, avctx);
594 }
595 }
596
597 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
598 next = buf_size;
599 } else {
600 next = h264_find_frame_end(p, buf, buf_size, avctx);
601
602 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
603 *poutbuf = NULL;
604 *poutbuf_size = 0;
605 return buf_size;
606 }
607
608 if (next < 0 && next != END_NOT_FOUND) {
609 av_assert1(pc->last_index + next >= 0);
610 h264_find_frame_end(p, &pc->buffer[pc->last_index + next], -next, avctx); // update state
611 }
612 }
613
614 parse_nal_units(s, avctx, buf, buf_size);
615
616 if (avctx->framerate.num)
617 avctx->time_base = av_inv_q(av_mul_q(avctx->framerate, (AVRational){avctx->ticks_per_frame, 1}));
618 if (p->sei.picture_timing.cpb_removal_delay >= 0) {
619 s->dts_sync_point = p->sei.buffering_period.present;
620 s->dts_ref_dts_delta = p->sei.picture_timing.cpb_removal_delay;
621 s->pts_dts_delta = p->sei.picture_timing.dpb_output_delay;
622 } else {
623 s->dts_sync_point = INT_MIN;
624 s->dts_ref_dts_delta = INT_MIN;
625 s->pts_dts_delta = INT_MIN;
626 }
627
628 if (s->flags & PARSER_FLAG_ONCE) {
629 s->flags &= PARSER_FLAG_COMPLETE_FRAMES;
630 }
631
632 if (s->dts_sync_point >= 0) {
633 int64_t den = avctx->time_base.den * (int64_t)avctx->pkt_timebase.num;
634 if (den > 0) {
635 int64_t num = avctx->time_base.num * (int64_t)avctx->pkt_timebase.den;
636 if (s->dts != AV_NOPTS_VALUE) {
637 // got DTS from the stream, update reference timestamp
638 p->reference_dts = s->dts - av_rescale(s->dts_ref_dts_delta, num, den);
639 } else if (p->reference_dts != AV_NOPTS_VALUE) {
640 // compute DTS based on reference timestamp
641 s->dts = p->reference_dts + av_rescale(s->dts_ref_dts_delta, num, den);
642 }
643
644 if (p->reference_dts != AV_NOPTS_VALUE && s->pts == AV_NOPTS_VALUE)
645 s->pts = s->dts + av_rescale(s->pts_dts_delta, num, den);
646
647 if (s->dts_sync_point > 0)
648 p->reference_dts = s->dts; // new reference
649 }
650 }
651
652 *poutbuf = buf;
653 *poutbuf_size = buf_size;
654 return next;
655}
656
657static int h264_split(AVCodecContext *avctx,
658 const uint8_t *buf, int buf_size)
659{
660 uint32_t state = -1;
661 int has_sps = 0;
662 int has_pps = 0;
663 const uint8_t *ptr = buf, *end = buf + buf_size;
664 int nalu_type;
665
666 while (ptr < end) {
667 ptr = avpriv_find_start_code(ptr, end, &state);
668 if ((state & 0xFFFFFF00) != 0x100)
669 break;
670 nalu_type = state & 0x1F;
671 if (nalu_type == H264_NAL_SPS) {
672 has_sps = 1;
673 } else if (nalu_type == H264_NAL_PPS)
674 has_pps = 1;
675 /* else if (nalu_type == 0x01 ||
676 * nalu_type == 0x02 ||
677 * nalu_type == 0x05) {
678 * }
679 */
680 else if ((nalu_type != H264_NAL_SEI || has_pps) &&
681 nalu_type != H264_NAL_AUD && nalu_type != H264_NAL_SPS_EXT &&
682 nalu_type != 0x0f) {
683 if (has_sps) {
684 while (ptr - 4 > buf && ptr[-5] == 0)
685 ptr--;
686 return ptr - 4 - buf;
687 }
688 }
689 }
690
691 return 0;
692}
693
694static void h264_close(AVCodecParserContext *s)
695{
696 H264ParseContext *p = s->priv_data;
697 ParseContext *pc = &p->pc;
698
699 av_freep(&pc->buffer);
700
701 ff_h264_sei_uninit(&p->sei);
702 ff_h264_ps_uninit(&p->ps);
703}
704
705static av_cold int init(AVCodecParserContext *s)
706{
707 H264ParseContext *p = s->priv_data;
708
709 p->reference_dts = AV_NOPTS_VALUE;
710 p->last_frame_num = INT_MAX;
711 ff_h264dsp_init(&p->h264dsp, 8, 1);
712 return 0;
713}
714
715AVCodecParser ff_h264_parser = {
716 .codec_ids = { AV_CODEC_ID_H264 },
717 .priv_data_size = sizeof(H264ParseContext),
718 .parser_init = init,
719 .parser_parse = h264_parse,
720 .parser_close = h264_close,
721 .split = h264_split,
722};
723
generated by cgit at 2024-05-10 09:21:41 (GMT)