Merge commit '5c2fb561d94fc51d76ab21d6f7cc5b6cc3aa599c'
[ffmpeg.git] / libavcodec / h264_parser.c
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
50 typedef 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 } H264ParseContext;
64
65
66 static int h264_find_frame_end(H264ParseContext *p, const uint8_t *buf,
67                                int buf_size, void *logctx)
68 {
69     int i, j;
70     uint32_t state;
71     ParseContext *pc = &p->pc;
72
73     int next_avc = p->is_avc ? 0 : buf_size;
74 //    mb_addr= pc->mb_addr - 1;
75     state = pc->state;
76     if (state > 13)
77         state = 7;
78
79     if (p->is_avc && !p->nal_length_size)
80         av_log(logctx, AV_LOG_ERROR, "AVC-parser: nal length size invalid\n");
81
82     for (i = 0; i < buf_size; i++) {
83         if (i >= next_avc) {
84             int nalsize = 0;
85             i = next_avc;
86             for (j = 0; j < p->nal_length_size; j++)
87                 nalsize = (nalsize << 8) | buf[i++];
88             if (nalsize <= 0 || nalsize > buf_size - i) {
89                 av_log(logctx, AV_LOG_ERROR, "AVC-parser: nal size %d remaining %d\n", nalsize, buf_size - i);
90                 return buf_size;
91             }
92             next_avc = i + nalsize;
93             state    = 5;
94         }
95
96         if (state == 7) {
97             i += p->h264dsp.startcode_find_candidate(buf + i, next_avc - i);
98             if (i < next_avc)
99                 state = 2;
100         } else if (state <= 2) {
101             if (buf[i] == 1)
102                 state ^= 5;            // 2->7, 1->4, 0->5
103             else if (buf[i])
104                 state = 7;
105             else
106                 state >>= 1;           // 2->1, 1->0, 0->0
107         } else if (state <= 5) {
108             int nalu_type = buf[i] & 0x1F;
109             if (nalu_type == H264_NAL_SEI || nalu_type == H264_NAL_SPS ||
110                 nalu_type == H264_NAL_PPS || nalu_type == H264_NAL_AUD) {
111                 if (pc->frame_start_found) {
112                     i++;
113                     goto found;
114                 }
115             } else if (nalu_type == H264_NAL_SLICE || nalu_type == H264_NAL_DPA ||
116                        nalu_type == H264_NAL_IDR_SLICE) {
117                 state += 8;
118                 continue;
119             }
120             state = 7;
121         } else {
122             p->parse_history[p->parse_history_count++] = buf[i];
123             if (p->parse_history_count > 5) {
124                 unsigned int mb, last_mb = p->parse_last_mb;
125                 GetBitContext gb;
126
127                 init_get_bits(&gb, p->parse_history, 8*p->parse_history_count);
128                 p->parse_history_count = 0;
129                 mb= get_ue_golomb_long(&gb);
130                 p->parse_last_mb = mb;
131                 if (pc->frame_start_found) {
132                     if (mb <= last_mb)
133                         goto found;
134                 } else
135                     pc->frame_start_found = 1;
136                 state = 7;
137             }
138         }
139     }
140     pc->state = state;
141     if (p->is_avc)
142         return next_avc;
143     return END_NOT_FOUND;
144
145 found:
146     pc->state             = 7;
147     pc->frame_start_found = 0;
148     if (p->is_avc)
149         return next_avc;
150     return i - (state & 5) - 5 * (state > 7);
151 }
152
153 static int scan_mmco_reset(AVCodecParserContext *s, GetBitContext *gb,
154                            void *logctx)
155 {
156     H264PredWeightTable pwt;
157     int slice_type_nos = s->pict_type & 3;
158     H264ParseContext *p = s->priv_data;
159     int list_count, ref_count[2];
160
161
162     if (p->ps.pps->redundant_pic_cnt_present)
163         get_ue_golomb(gb); // redundant_pic_count
164
165     if (slice_type_nos == AV_PICTURE_TYPE_B)
166         get_bits1(gb); // direct_spatial_mv_pred
167
168     if (ff_h264_parse_ref_count(&list_count, ref_count, gb, p->ps.pps,
169                                 slice_type_nos, p->picture_structure, logctx) < 0)
170         return AVERROR_INVALIDDATA;
171
172     if (slice_type_nos != AV_PICTURE_TYPE_I) {
173         int list;
174         for (list = 0; list < list_count; list++) {
175             if (get_bits1(gb)) {
176                 int index;
177                 for (index = 0; ; index++) {
178                     unsigned int reordering_of_pic_nums_idc = get_ue_golomb_31(gb);
179
180                     if (reordering_of_pic_nums_idc < 3)
181                         get_ue_golomb_long(gb);
182                     else if (reordering_of_pic_nums_idc > 3) {
183                         av_log(logctx, AV_LOG_ERROR,
184                                "illegal reordering_of_pic_nums_idc %d\n",
185                                reordering_of_pic_nums_idc);
186                         return AVERROR_INVALIDDATA;
187                     } else
188                         break;
189
190                     if (index >= ref_count[list]) {
191                         av_log(logctx, AV_LOG_ERROR,
192                                "reference count %d overflow\n", index);
193                         return AVERROR_INVALIDDATA;
194                     }
195                 }
196             }
197         }
198     }
199
200     if ((p->ps.pps->weighted_pred && slice_type_nos == AV_PICTURE_TYPE_P) ||
201         (p->ps.pps->weighted_bipred_idc == 1 && slice_type_nos == AV_PICTURE_TYPE_B))
202         ff_h264_pred_weight_table(gb, p->ps.sps, ref_count, slice_type_nos,
203                                   &pwt, logctx);
204
205     if (get_bits1(gb)) { // adaptive_ref_pic_marking_mode_flag
206         int i;
207         for (i = 0; i < MAX_MMCO_COUNT; i++) {
208             MMCOOpcode opcode = get_ue_golomb_31(gb);
209             if (opcode > (unsigned) MMCO_LONG) {
210                 av_log(logctx, AV_LOG_ERROR,
211                        "illegal memory management control operation %d\n",
212                        opcode);
213                 return AVERROR_INVALIDDATA;
214             }
215             if (opcode == MMCO_END)
216                return 0;
217             else if (opcode == MMCO_RESET)
218                 return 1;
219
220             if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG)
221                 get_ue_golomb_long(gb); // difference_of_pic_nums_minus1
222             if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED ||
223                 opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG)
224                 get_ue_golomb_31(gb);
225         }
226     }
227
228     return 0;
229 }
230
231 static inline int get_avc_nalsize(H264ParseContext *p, const uint8_t *buf,
232                                   int buf_size, int *buf_index, void *logctx)
233 {
234     int i, nalsize = 0;
235
236     if (*buf_index >= buf_size - p->nal_length_size) {
237         // the end of the buffer is reached, refill it
238         return AVERROR(EAGAIN);
239     }
240
241     for (i = 0; i < p->nal_length_size; i++)
242         nalsize = ((unsigned)nalsize << 8) | buf[(*buf_index)++];
243     if (nalsize <= 0 || nalsize > buf_size - *buf_index) {
244         av_log(logctx, AV_LOG_ERROR,
245                "AVC: nal size %d\n", nalsize);
246         return AVERROR_INVALIDDATA;
247     }
248     return nalsize;
249 }
250
251 /**
252  * Parse NAL units of found picture and decode some basic information.
253  *
254  * @param s parser context.
255  * @param avctx codec context.
256  * @param buf buffer with field/frame data.
257  * @param buf_size size of the buffer.
258  */
259 static inline int parse_nal_units(AVCodecParserContext *s,
260                                   AVCodecContext *avctx,
261                                   const uint8_t * const buf, int buf_size)
262 {
263     H264ParseContext *p = s->priv_data;
264     H2645NAL nal = { NULL };
265     int buf_index, next_avc;
266     unsigned int pps_id;
267     unsigned int slice_type;
268     int state = -1, got_reset = 0;
269     int q264 = buf_size >=4 && !memcmp("Q264", buf, 4);
270     int field_poc[2];
271     int ret;
272
273     /* set some sane default values */
274     s->pict_type         = AV_PICTURE_TYPE_I;
275     s->key_frame         = 0;
276     s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
277
278     ff_h264_sei_uninit(&p->sei);
279     p->sei.frame_packing.frame_packing_arrangement_cancel_flag = -1;
280
281     if (!buf_size)
282         return 0;
283
284     buf_index     = 0;
285     next_avc      = p->is_avc ? 0 : buf_size;
286     for (;;) {
287         const SPS *sps;
288         int src_length, consumed, nalsize = 0;
289
290         if (buf_index >= next_avc) {
291             nalsize = get_avc_nalsize(p, buf, buf_size, &buf_index, avctx);
292             if (nalsize < 0)
293                 break;
294             next_avc = buf_index + nalsize;
295         } else {
296             buf_index = find_start_code(buf, buf_size, buf_index, next_avc);
297             if (buf_index >= buf_size)
298                 break;
299             if (buf_index >= next_avc)
300                 continue;
301         }
302         src_length = next_avc - buf_index;
303
304         state = buf[buf_index];
305         switch (state & 0x1f) {
306         case H264_NAL_SLICE:
307         case H264_NAL_IDR_SLICE:
308             // Do not walk the whole buffer just to decode slice header
309             if ((state & 0x1f) == H264_NAL_IDR_SLICE || ((state >> 5) & 0x3) == 0) {
310                 /* IDR or disposable slice
311                  * No need to decode many bytes because MMCOs shall not be present. */
312                 if (src_length > 60)
313                     src_length = 60;
314             } else {
315                 /* To decode up to MMCOs */
316                 if (src_length > 1000)
317                     src_length = 1000;
318             }
319             break;
320         }
321         consumed = ff_h2645_extract_rbsp(buf + buf_index, src_length, &nal);
322         if (consumed < 0)
323             break;
324
325         buf_index += consumed;
326
327         ret = init_get_bits8(&nal.gb, nal.data, nal.size);
328         if (ret < 0)
329             goto fail;
330         get_bits1(&nal.gb);
331         nal.ref_idc = get_bits(&nal.gb, 2);
332         nal.type    = get_bits(&nal.gb, 5);
333
334         switch (nal.type) {
335         case H264_NAL_SPS:
336             ff_h264_decode_seq_parameter_set(&nal.gb, avctx, &p->ps, 0);
337             break;
338         case H264_NAL_PPS:
339             ff_h264_decode_picture_parameter_set(&nal.gb, avctx, &p->ps,
340                                                  nal.size_bits);
341             break;
342         case H264_NAL_SEI:
343             ff_h264_sei_decode(&p->sei, &nal.gb, &p->ps, avctx);
344             break;
345         case H264_NAL_IDR_SLICE:
346             s->key_frame = 1;
347
348             p->poc.prev_frame_num        = 0;
349             p->poc.prev_frame_num_offset = 0;
350             p->poc.prev_poc_msb          =
351             p->poc.prev_poc_lsb          = 0;
352         /* fall through */
353         case H264_NAL_SLICE:
354             get_ue_golomb_long(&nal.gb);  // skip first_mb_in_slice
355             slice_type   = get_ue_golomb_31(&nal.gb);
356             s->pict_type = ff_h264_golomb_to_pict_type[slice_type % 5];
357             if (p->sei.recovery_point.recovery_frame_cnt >= 0) {
358                 /* key frame, since recovery_frame_cnt is set */
359                 s->key_frame = 1;
360             }
361             pps_id = get_ue_golomb(&nal.gb);
362             if (pps_id >= MAX_PPS_COUNT) {
363                 av_log(avctx, AV_LOG_ERROR,
364                        "pps_id %u out of range\n", pps_id);
365                 goto fail;
366             }
367             if (!p->ps.pps_list[pps_id]) {
368                 av_log(avctx, AV_LOG_ERROR,
369                        "non-existing PPS %u referenced\n", pps_id);
370                 goto fail;
371             }
372
373             av_buffer_unref(&p->ps.pps_ref);
374             av_buffer_unref(&p->ps.sps_ref);
375             p->ps.pps = NULL;
376             p->ps.sps = NULL;
377             p->ps.pps_ref = av_buffer_ref(p->ps.pps_list[pps_id]);
378             if (!p->ps.pps_ref)
379                 goto fail;
380             p->ps.pps = (const PPS*)p->ps.pps_ref->data;
381
382             if (!p->ps.sps_list[p->ps.pps->sps_id]) {
383                 av_log(avctx, AV_LOG_ERROR,
384                        "non-existing SPS %u referenced\n", p->ps.pps->sps_id);
385                 goto fail;
386             }
387
388             p->ps.sps_ref = av_buffer_ref(p->ps.sps_list[p->ps.pps->sps_id]);
389             if (!p->ps.sps_ref)
390                 goto fail;
391             p->ps.sps = (const SPS*)p->ps.sps_ref->data;
392
393             sps = p->ps.sps;
394
395             // heuristic to detect non marked keyframes
396             if (p->ps.sps->ref_frame_count <= 1 && p->ps.pps->ref_count[0] <= 1 && s->pict_type == AV_PICTURE_TYPE_I)
397                 s->key_frame = 1;
398
399             p->poc.frame_num = get_bits(&nal.gb, sps->log2_max_frame_num);
400
401             s->coded_width  = 16 * sps->mb_width;
402             s->coded_height = 16 * sps->mb_height;
403             s->width        = s->coded_width  - (sps->crop_right + sps->crop_left);
404             s->height       = s->coded_height - (sps->crop_top   + sps->crop_bottom);
405             if (s->width <= 0 || s->height <= 0) {
406                 s->width  = s->coded_width;
407                 s->height = s->coded_height;
408             }
409
410             switch (sps->bit_depth_luma) {
411             case 9:
412                 if (sps->chroma_format_idc == 3)      s->format = AV_PIX_FMT_YUV444P9;
413                 else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P9;
414                 else                                  s->format = AV_PIX_FMT_YUV420P9;
415                 break;
416             case 10:
417                 if (sps->chroma_format_idc == 3)      s->format = AV_PIX_FMT_YUV444P10;
418                 else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P10;
419                 else                                  s->format = AV_PIX_FMT_YUV420P10;
420                 break;
421             case 8:
422                 if (sps->chroma_format_idc == 3)      s->format = AV_PIX_FMT_YUV444P;
423                 else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P;
424                 else                                  s->format = AV_PIX_FMT_YUV420P;
425                 break;
426             default:
427                 s->format = AV_PIX_FMT_NONE;
428             }
429
430             avctx->profile = ff_h264_get_profile(sps);
431             avctx->level   = sps->level_idc;
432
433             if (sps->frame_mbs_only_flag) {
434                 p->picture_structure = PICT_FRAME;
435             } else {
436                 if (get_bits1(&nal.gb)) { // field_pic_flag
437                     p->picture_structure = PICT_TOP_FIELD + get_bits1(&nal.gb); // bottom_field_flag
438                 } else {
439                     p->picture_structure = PICT_FRAME;
440                 }
441             }
442
443             if (nal.type == H264_NAL_IDR_SLICE)
444                 get_ue_golomb_long(&nal.gb); /* idr_pic_id */
445             if (sps->poc_type == 0) {
446                 p->poc.poc_lsb = get_bits(&nal.gb, sps->log2_max_poc_lsb);
447
448                 if (p->ps.pps->pic_order_present == 1 &&
449                     p->picture_structure == PICT_FRAME)
450                     p->poc.delta_poc_bottom = get_se_golomb(&nal.gb);
451             }
452
453             if (sps->poc_type == 1 &&
454                 !sps->delta_pic_order_always_zero_flag) {
455                 p->poc.delta_poc[0] = get_se_golomb(&nal.gb);
456
457                 if (p->ps.pps->pic_order_present == 1 &&
458                     p->picture_structure == PICT_FRAME)
459                     p->poc.delta_poc[1] = get_se_golomb(&nal.gb);
460             }
461
462             /* Decode POC of this picture.
463              * The prev_ values needed for decoding POC of the next picture are not set here. */
464             field_poc[0] = field_poc[1] = INT_MAX;
465             ff_h264_init_poc(field_poc, &s->output_picture_number, sps,
466                              &p->poc, p->picture_structure, nal.ref_idc);
467
468             /* Continue parsing to check if MMCO_RESET is present.
469              * FIXME: MMCO_RESET could appear in non-first slice.
470              *        Maybe, we should parse all undisposable non-IDR slice of this
471              *        picture until encountering MMCO_RESET in a slice of it. */
472             if (nal.ref_idc && nal.type != H264_NAL_IDR_SLICE) {
473                 got_reset = scan_mmco_reset(s, &nal.gb, avctx);
474                 if (got_reset < 0)
475                     goto fail;
476             }
477
478             /* Set up the prev_ values for decoding POC of the next picture. */
479             p->poc.prev_frame_num        = got_reset ? 0 : p->poc.frame_num;
480             p->poc.prev_frame_num_offset = got_reset ? 0 : p->poc.frame_num_offset;
481             if (nal.ref_idc != 0) {
482                 if (!got_reset) {
483                     p->poc.prev_poc_msb = p->poc.poc_msb;
484                     p->poc.prev_poc_lsb = p->poc.poc_lsb;
485                 } else {
486                     p->poc.prev_poc_msb = 0;
487                     p->poc.prev_poc_lsb =
488                         p->picture_structure == PICT_BOTTOM_FIELD ? 0 : field_poc[0];
489                 }
490             }
491
492             if (sps->pic_struct_present_flag) {
493                 switch (p->sei.picture_timing.pic_struct) {
494                 case SEI_PIC_STRUCT_TOP_FIELD:
495                 case SEI_PIC_STRUCT_BOTTOM_FIELD:
496                     s->repeat_pict = 0;
497                     break;
498                 case SEI_PIC_STRUCT_FRAME:
499                 case SEI_PIC_STRUCT_TOP_BOTTOM:
500                 case SEI_PIC_STRUCT_BOTTOM_TOP:
501                     s->repeat_pict = 1;
502                     break;
503                 case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
504                 case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
505                     s->repeat_pict = 2;
506                     break;
507                 case SEI_PIC_STRUCT_FRAME_DOUBLING:
508                     s->repeat_pict = 3;
509                     break;
510                 case SEI_PIC_STRUCT_FRAME_TRIPLING:
511                     s->repeat_pict = 5;
512                     break;
513                 default:
514                     s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
515                     break;
516                 }
517             } else {
518                 s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
519             }
520
521             if (p->picture_structure == PICT_FRAME) {
522                 s->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
523                 if (sps->pic_struct_present_flag) {
524                     switch (p->sei.picture_timing.pic_struct) {
525                     case SEI_PIC_STRUCT_TOP_BOTTOM:
526                     case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
527                         s->field_order = AV_FIELD_TT;
528                         break;
529                     case SEI_PIC_STRUCT_BOTTOM_TOP:
530                     case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
531                         s->field_order = AV_FIELD_BB;
532                         break;
533                     default:
534                         s->field_order = AV_FIELD_PROGRESSIVE;
535                         break;
536                     }
537                 } else {
538                     if (field_poc[0] < field_poc[1])
539                         s->field_order = AV_FIELD_TT;
540                     else if (field_poc[0] > field_poc[1])
541                         s->field_order = AV_FIELD_BB;
542                     else
543                         s->field_order = AV_FIELD_PROGRESSIVE;
544                 }
545             } else {
546                 if (p->picture_structure == PICT_TOP_FIELD)
547                     s->picture_structure = AV_PICTURE_STRUCTURE_TOP_FIELD;
548                 else
549                     s->picture_structure = AV_PICTURE_STRUCTURE_BOTTOM_FIELD;
550                 s->field_order = AV_FIELD_UNKNOWN;
551             }
552
553             av_freep(&nal.rbsp_buffer);
554             return 0; /* no need to evaluate the rest */
555         }
556     }
557     if (q264) {
558         av_freep(&nal.rbsp_buffer);
559         return 0;
560     }
561     /* didn't find a picture! */
562     av_log(avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
563 fail:
564     av_freep(&nal.rbsp_buffer);
565     return -1;
566 }
567
568 static int h264_parse(AVCodecParserContext *s,
569                       AVCodecContext *avctx,
570                       const uint8_t **poutbuf, int *poutbuf_size,
571                       const uint8_t *buf, int buf_size)
572 {
573     H264ParseContext *p = s->priv_data;
574     ParseContext *pc = &p->pc;
575     int next;
576
577     if (!p->got_first) {
578         p->got_first = 1;
579         if (avctx->extradata_size) {
580             ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,
581                                      &p->ps, &p->is_avc, &p->nal_length_size,
582                                      avctx->err_recognition, avctx);
583         }
584     }
585
586     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
587         next = buf_size;
588     } else {
589         next = h264_find_frame_end(p, buf, buf_size, avctx);
590
591         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
592             *poutbuf      = NULL;
593             *poutbuf_size = 0;
594             return buf_size;
595         }
596
597         if (next < 0 && next != END_NOT_FOUND) {
598             av_assert1(pc->last_index + next >= 0);
599             h264_find_frame_end(p, &pc->buffer[pc->last_index + next], -next, avctx); // update state
600         }
601     }
602
603     parse_nal_units(s, avctx, buf, buf_size);
604
605     if (avctx->framerate.num)
606         avctx->time_base = av_inv_q(av_mul_q(avctx->framerate, (AVRational){avctx->ticks_per_frame, 1}));
607     if (p->sei.picture_timing.cpb_removal_delay >= 0) {
608         s->dts_sync_point    = p->sei.buffering_period.present;
609         s->dts_ref_dts_delta = p->sei.picture_timing.cpb_removal_delay;
610         s->pts_dts_delta     = p->sei.picture_timing.dpb_output_delay;
611     } else {
612         s->dts_sync_point    = INT_MIN;
613         s->dts_ref_dts_delta = INT_MIN;
614         s->pts_dts_delta     = INT_MIN;
615     }
616
617     if (s->flags & PARSER_FLAG_ONCE) {
618         s->flags &= PARSER_FLAG_COMPLETE_FRAMES;
619     }
620
621     *poutbuf      = buf;
622     *poutbuf_size = buf_size;
623     return next;
624 }
625
626 static int h264_split(AVCodecContext *avctx,
627                       const uint8_t *buf, int buf_size)
628 {
629     uint32_t state = -1;
630     int has_sps    = 0;
631     int has_pps    = 0;
632     const uint8_t *ptr = buf, *end = buf + buf_size;
633     int nalu_type;
634
635     while (ptr < end) {
636         ptr = avpriv_find_start_code(ptr, end, &state);
637         if ((state & 0xFFFFFF00) != 0x100)
638             break;
639         nalu_type = state & 0x1F;
640         if (nalu_type == H264_NAL_SPS) {
641             has_sps = 1;
642         } else if (nalu_type == H264_NAL_PPS)
643             has_pps = 1;
644         /* else if (nalu_type == 0x01 ||
645          *     nalu_type == 0x02 ||
646          *     nalu_type == 0x05) {
647          *  }
648          */
649         else if ((nalu_type != H264_NAL_SEI || has_pps) &&
650                   nalu_type != H264_NAL_AUD && nalu_type != H264_NAL_SPS_EXT &&
651                   nalu_type != 0x0f) {
652             if (has_sps) {
653                 while (ptr - 4 > buf && ptr[-5] == 0)
654                     ptr--;
655                 return ptr - 4 - buf;
656             }
657         }
658     }
659
660     return 0;
661 }
662
663 static void h264_close(AVCodecParserContext *s)
664 {
665     H264ParseContext *p = s->priv_data;
666     ParseContext *pc = &p->pc;
667
668     av_freep(&pc->buffer);
669
670     ff_h264_sei_uninit(&p->sei);
671     ff_h264_ps_uninit(&p->ps);
672 }
673
674 static av_cold int init(AVCodecParserContext *s)
675 {
676     H264ParseContext *p = s->priv_data;
677
678     ff_h264dsp_init(&p->h264dsp, 8, 1);
679     return 0;
680 }
681
682 AVCodecParser ff_h264_parser = {
683     .codec_ids      = { AV_CODEC_ID_H264 },
684     .priv_data_size = sizeof(H264ParseContext),
685     .parser_init    = init,
686     .parser_parse   = h264_parse,
687     .parser_close   = h264_close,
688     .split          = h264_split,
689 };