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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:
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_IDR_SLICE:
335 s->key_frame = 1;
336
337 p->poc.prev_frame_num = 0;
338 p->poc.prev_frame_num_offset = 0;
339 p->poc.prev_poc_msb =
340 p->poc.prev_poc_lsb = 0;
341 /* fall through */
342 case H264_NAL_SLICE:
343 get_ue_golomb_long(&nal.gb); // skip first_mb_in_slice
344 slice_type = get_ue_golomb_31(&nal.gb);
345 s->pict_type = ff_h264_golomb_to_pict_type[slice_type % 5];
346 if (p->sei.recovery_point.recovery_frame_cnt >= 0) {
347 /* key frame, since recovery_frame_cnt is set */
348 s->key_frame = 1;
349 }
350 /* set key_frame for I frame*/
351 if (s->pict_type == AV_PICTURE_TYPE_I)
352 s->key_frame = 1;
353 pps_id = get_ue_golomb(&nal.gb);
354 if (pps_id >= MAX_PPS_COUNT) {
355 av_log(avctx, AV_LOG_ERROR,
356 "pps_id %u out of range\n", pps_id);
357 goto fail;
358 }
359 if (!p->ps.pps_list[pps_id]) {
360 av_log(avctx, AV_LOG_ERROR,
361 "non-existing PPS %u referenced\n", pps_id);
362 goto fail;
363 }
364
365 av_buffer_unref(&p->ps.pps_ref);
366 av_buffer_unref(&p->ps.sps_ref);
367 p->ps.pps = NULL;
368 p->ps.sps = NULL;
369 p->ps.pps_ref = av_buffer_ref(p->ps.pps_list[pps_id]);
370 if (!p->ps.pps_ref)
371 goto fail;
372 p->ps.pps = (const PPS*)p->ps.pps_ref->data;
373
374 if (!p->ps.sps_list[p->ps.pps->sps_id]) {
375 av_log(avctx, AV_LOG_ERROR,
376 "non-existing SPS %u referenced\n", p->ps.pps->sps_id);
377 goto fail;
378 }
379
380 p->ps.sps_ref = av_buffer_ref(p->ps.sps_list[p->ps.pps->sps_id]);
381 if (!p->ps.sps_ref)
382 goto fail;
383 p->ps.sps = (const SPS*)p->ps.sps_ref->data;
384
385 sps = p->ps.sps;
386
387 // heuristic to detect non marked keyframes
388 if (p->ps.sps->ref_frame_count <= 1 && p->ps.pps->ref_count[0] <= 1 && s->pict_type == AV_PICTURE_TYPE_I)
389 s->key_frame = 1;
390
391 p->poc.frame_num = get_bits(&nal.gb, sps->log2_max_frame_num);
392
393 s->coded_width = 16 * sps->mb_width;
394 s->coded_height = 16 * sps->mb_height;
395 s->width = s->coded_width - (sps->crop_right + sps->crop_left);
396 s->height = s->coded_height - (sps->crop_top + sps->crop_bottom);
397 if (s->width <= 0 || s->height <= 0) {
398 s->width = s->coded_width;
399 s->height = s->coded_height;
400 }
401
402 switch (sps->bit_depth_luma) {
403 case 9:
404 if (sps->chroma_format_idc == 3) s->format = AV_PIX_FMT_YUV444P9;
405 else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P9;
406 else s->format = AV_PIX_FMT_YUV420P9;
407 break;
408 case 10:
409 if (sps->chroma_format_idc == 3) s->format = AV_PIX_FMT_YUV444P10;
410 else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P10;
411 else s->format = AV_PIX_FMT_YUV420P10;
412 break;
413 case 8:
414 if (sps->chroma_format_idc == 3) s->format = AV_PIX_FMT_YUV444P;
415 else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P;
416 else s->format = AV_PIX_FMT_YUV420P;
417 break;
418 default:
419 s->format = AV_PIX_FMT_NONE;
420 }
421
422 avctx->profile = ff_h264_get_profile(sps);
423 avctx->level = sps->level_idc;
424
425 if (sps->frame_mbs_only_flag) {
426 p->picture_structure = PICT_FRAME;
427 } else {
428 if (get_bits1(&nal.gb)) { // field_pic_flag
429 p->picture_structure = PICT_TOP_FIELD + get_bits1(&nal.gb); // bottom_field_flag
430 } else {
431 p->picture_structure = PICT_FRAME;
432 }
433 }
434
435 if (nal.type == H264_NAL_IDR_SLICE)
436 get_ue_golomb_long(&nal.gb); /* idr_pic_id */
437 if (sps->poc_type == 0) {
438 p->poc.poc_lsb = get_bits(&nal.gb, sps->log2_max_poc_lsb);
439
440 if (p->ps.pps->pic_order_present == 1 &&
441 p->picture_structure == PICT_FRAME)
442 p->poc.delta_poc_bottom = get_se_golomb(&nal.gb);
443 }
444
445 if (sps->poc_type == 1 &&
446 !sps->delta_pic_order_always_zero_flag) {
447 p->poc.delta_poc[0] = get_se_golomb(&nal.gb);
448
449 if (p->ps.pps->pic_order_present == 1 &&
450 p->picture_structure == PICT_FRAME)
451 p->poc.delta_poc[1] = get_se_golomb(&nal.gb);
452 }
453
454 /* Decode POC of this picture.
455 * The prev_ values needed for decoding POC of the next picture are not set here. */
456 field_poc[0] = field_poc[1] = INT_MAX;
457 ff_h264_init_poc(field_poc, &s->output_picture_number, sps,
458 &p->poc, p->picture_structure, nal.ref_idc);
459
460 /* Continue parsing to check if MMCO_RESET is present.
461 * FIXME: MMCO_RESET could appear in non-first slice.
462 * Maybe, we should parse all undisposable non-IDR slice of this
463 * picture until encountering MMCO_RESET in a slice of it. */
464 if (nal.ref_idc && nal.type != H264_NAL_IDR_SLICE) {
465 got_reset = scan_mmco_reset(s, &nal.gb, avctx);
466 if (got_reset < 0)
467 goto fail;
468 }
469
470 /* Set up the prev_ values for decoding POC of the next picture. */
471 p->poc.prev_frame_num = got_reset ? 0 : p->poc.frame_num;
472 p->poc.prev_frame_num_offset = got_reset ? 0 : p->poc.frame_num_offset;
473 if (nal.ref_idc != 0) {
474 if (!got_reset) {
475 p->poc.prev_poc_msb = p->poc.poc_msb;
476 p->poc.prev_poc_lsb = p->poc.poc_lsb;
477 } else {
478 p->poc.prev_poc_msb = 0;
479 p->poc.prev_poc_lsb =
480 p->picture_structure == PICT_BOTTOM_FIELD ? 0 : field_poc[0];
481 }
482 }
483
484 if (sps->pic_struct_present_flag && p->sei.picture_timing.present) {
485 switch (p->sei.picture_timing.pic_struct) {
486 case SEI_PIC_STRUCT_TOP_FIELD:
487 case SEI_PIC_STRUCT_BOTTOM_FIELD:
488 s->repeat_pict = 0;
489 break;
490 case SEI_PIC_STRUCT_FRAME:
491 case SEI_PIC_STRUCT_TOP_BOTTOM:
492 case SEI_PIC_STRUCT_BOTTOM_TOP:
493 s->repeat_pict = 1;
494 break;
495 case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
496 case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
497 s->repeat_pict = 2;
498 break;
499 case SEI_PIC_STRUCT_FRAME_DOUBLING:
500 s->repeat_pict = 3;
501 break;
502 case SEI_PIC_STRUCT_FRAME_TRIPLING:
503 s->repeat_pict = 5;
504 break;
505 default:
506 s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
507 break;
508 }
509 } else {
510 s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
511 }
512
513 if (p->picture_structure == PICT_FRAME) {
514 s->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
515 if (sps->pic_struct_present_flag && p->sei.picture_timing.present) {
516 switch (p->sei.picture_timing.pic_struct) {
517 case SEI_PIC_STRUCT_TOP_BOTTOM:
518 case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
519 s->field_order = AV_FIELD_TT;
520 break;
521 case SEI_PIC_STRUCT_BOTTOM_TOP:
522 case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
523 s->field_order = AV_FIELD_BB;
524 break;
525 default:
526 s->field_order = AV_FIELD_PROGRESSIVE;
527 break;
528 }
529 } else {
530 if (field_poc[0] < field_poc[1])
531 s->field_order = AV_FIELD_TT;
532 else if (field_poc[0] > field_poc[1])
533 s->field_order = AV_FIELD_BB;
534 else
535 s->field_order = AV_FIELD_PROGRESSIVE;
536 }
537 } else {
538 if (p->picture_structure == PICT_TOP_FIELD)
539 s->picture_structure = AV_PICTURE_STRUCTURE_TOP_FIELD;
540 else
541 s->picture_structure = AV_PICTURE_STRUCTURE_BOTTOM_FIELD;
542 if (p->poc.frame_num == p->last_frame_num &&
543 p->last_picture_structure != AV_PICTURE_STRUCTURE_UNKNOWN &&
544 p->last_picture_structure != AV_PICTURE_STRUCTURE_FRAME &&
545 p->last_picture_structure != s->picture_structure) {
546 if (p->last_picture_structure == AV_PICTURE_STRUCTURE_TOP_FIELD)
547 s->field_order = AV_FIELD_TT;
548 else
549 s->field_order = AV_FIELD_BB;
550 } else {
551 s->field_order = AV_FIELD_UNKNOWN;
552 }
553 p->last_picture_structure = s->picture_structure;
554 p->last_frame_num = p->poc.frame_num;
555 }
556
557 av_freep(&nal.rbsp_buffer);
558 return 0; /* no need to evaluate the rest */
559 }
560 }
561 if (q264) {
562 av_freep(&nal.rbsp_buffer);
563 return 0;
564 }
565 /* didn't find a picture! */
566 av_log(avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
567fail:
568 av_freep(&nal.rbsp_buffer);
569 return -1;
570}
571
572static int h264_parse(AVCodecParserContext *s,
573 AVCodecContext *avctx,
574 const uint8_t **poutbuf, int *poutbuf_size,
575 const uint8_t *buf, int buf_size)
576{
577 H264ParseContext *p = s->priv_data;
578 ParseContext *pc = &p->pc;
579 int next;
580
581 if (!p->got_first) {
582 p->got_first = 1;
583 if (avctx->extradata_size) {
584 ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,
585 &p->ps, &p->is_avc, &p->nal_length_size,
586 avctx->err_recognition, avctx);
587 }
588 }
589
590 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
591 next = buf_size;
592 } else {
593 next = h264_find_frame_end(p, buf, buf_size, avctx);
594
595 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
596 *poutbuf = NULL;
597 *poutbuf_size = 0;
598 return buf_size;
599 }
600
601 if (next < 0 && next != END_NOT_FOUND) {
602 av_assert1(pc->last_index + next >= 0);
603 h264_find_frame_end(p, &pc->buffer[pc->last_index + next], -next, avctx); // update state
604 }
605 }
606
607 parse_nal_units(s, avctx, buf, buf_size);
608
609 if (avctx->framerate.num)
610 avctx->time_base = av_inv_q(av_mul_q(avctx->framerate, (AVRational){avctx->ticks_per_frame, 1}));
611 if (p->sei.picture_timing.cpb_removal_delay >= 0) {
612 s->dts_sync_point = p->sei.buffering_period.present;
613 s->dts_ref_dts_delta = p->sei.picture_timing.cpb_removal_delay;
614 s->pts_dts_delta = p->sei.picture_timing.dpb_output_delay;
615 } else {
616 s->dts_sync_point = INT_MIN;
617 s->dts_ref_dts_delta = INT_MIN;
618 s->pts_dts_delta = INT_MIN;
619 }
620
621 if (s->flags & PARSER_FLAG_ONCE) {
622 s->flags &= PARSER_FLAG_COMPLETE_FRAMES;
623 }
624
625 if (s->dts_sync_point >= 0) {
626 int64_t den = avctx->time_base.den * (int64_t)avctx->pkt_timebase.num;
627 if (den > 0) {
628 int64_t num = avctx->time_base.num * (int64_t)avctx->pkt_timebase.den;
629 if (s->dts != AV_NOPTS_VALUE) {
630 // got DTS from the stream, update reference timestamp
631 p->reference_dts = s->dts - av_rescale(s->dts_ref_dts_delta, num, den);
632 } else if (p->reference_dts != AV_NOPTS_VALUE) {
633 // compute DTS based on reference timestamp
634 s->dts = p->reference_dts + av_rescale(s->dts_ref_dts_delta, num, den);
635 }
636
637 if (p->reference_dts != AV_NOPTS_VALUE && s->pts == AV_NOPTS_VALUE)
638 s->pts = s->dts + av_rescale(s->pts_dts_delta, num, den);
639
640 if (s->dts_sync_point > 0)
641 p->reference_dts = s->dts; // new reference
642 }
643 }
644
645 *poutbuf = buf;
646 *poutbuf_size = buf_size;
647 return next;
648}
649
650static int h264_split(AVCodecContext *avctx,
651 const uint8_t *buf, int buf_size)
652{
653 uint32_t state = -1;
654 int has_sps = 0;
655 int has_pps = 0;
656 const uint8_t *ptr = buf, *end = buf + buf_size;
657 int nalu_type;
658
659 while (ptr < end) {
660 ptr = avpriv_find_start_code(ptr, end, &state);
661 if ((state & 0xFFFFFF00) != 0x100)
662 break;
663 nalu_type = state & 0x1F;
664 if (nalu_type == H264_NAL_SPS) {
665 has_sps = 1;
666 } else if (nalu_type == H264_NAL_PPS)
667 has_pps = 1;
668 /* else if (nalu_type == 0x01 ||
669 * nalu_type == 0x02 ||
670 * nalu_type == 0x05) {
671 * }
672 */
673 else if ((nalu_type != H264_NAL_SEI || has_pps) &&
674 nalu_type != H264_NAL_AUD && nalu_type != H264_NAL_SPS_EXT &&
675 nalu_type != 0x0f) {
676 if (has_sps) {
677 while (ptr - 4 > buf && ptr[-5] == 0)
678 ptr--;
679 return ptr - 4 - buf;
680 }
681 }
682 }
683
684 return 0;
685}
686
687static void h264_close(AVCodecParserContext *s)
688{
689 H264ParseContext *p = s->priv_data;
690 ParseContext *pc = &p->pc;
691
692 av_freep(&pc->buffer);
693
694 ff_h264_sei_uninit(&p->sei);
695 ff_h264_ps_uninit(&p->ps);
696}
697
698static av_cold int init(AVCodecParserContext *s)
699{
700 H264ParseContext *p = s->priv_data;
701
702 p->reference_dts = AV_NOPTS_VALUE;
703 p->last_frame_num = INT_MAX;
704 ff_h264dsp_init(&p->h264dsp, 8, 1);
705 return 0;
706}
707
708AVCodecParser ff_h264_parser = {
709 .codec_ids = { AV_CODEC_ID_H264 },
710 .priv_data_size = sizeof(H264ParseContext),
711 .parser_init = init,
712 .parser_parse = h264_parse,
713 .parser_close = h264_close,
714 .split = h264_split,
715};
716
generated by cgit at 2024-05-10 05:59:18 (GMT)