Merge commit '088f38a4f9f54bb923405c67c9e72d96d90aa284'
[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 / MPEG4 part10 parser.
25  * @author Michael Niedermayer <michaelni@gmx.at>
26  */
27
28 #define UNCHECKED_BITSTREAM_READER 1
29
30 #include "parser.h"
31 #include "h264data.h"
32 #include "golomb.h"
33 #include "internal.h"
34
35
36 static int h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
37 {
38     int i, j;
39     uint32_t state;
40     ParseContext *pc = &h->parse_context;
41     int next_avc= h->is_avc ? 0 : buf_size;
42
43 //    mb_addr= pc->mb_addr - 1;
44     state= pc->state;
45     if(state>13)
46         state= 7;
47
48     if(h->is_avc && !h->nal_length_size)
49         av_log(h->avctx, AV_LOG_ERROR, "AVC-parser: nal length size invalid\n");
50
51     for(i=0; i<buf_size; i++){
52         if(i >= next_avc) {
53             int nalsize = 0;
54             i = next_avc;
55             for(j = 0; j < h->nal_length_size; j++)
56                 nalsize = (nalsize << 8) | buf[i++];
57             if(nalsize <= 0 || nalsize > buf_size - i){
58                 av_log(h->avctx, AV_LOG_ERROR, "AVC-parser: nal size %d remaining %d\n", nalsize, buf_size - i);
59                 return buf_size;
60             }
61             next_avc= i + nalsize;
62             state= 5;
63         }
64
65         if(state==7){
66 #if HAVE_FAST_UNALIGNED
67         /* we check i<buf_size instead of i+3/7 because its simpler
68          * and there should be FF_INPUT_BUFFER_PADDING_SIZE bytes at the end
69          */
70 #    if HAVE_FAST_64BIT
71             while(i<next_avc && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
72                 i+=8;
73 #    else
74             while(i<next_avc && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
75                 i+=4;
76 #    endif
77 #endif
78             for(; i<next_avc; i++){
79                 if(!buf[i]){
80                     state=2;
81                     break;
82                 }
83             }
84         }else if(state<=2){
85             if(buf[i]==1)   state^= 5; //2->7, 1->4, 0->5
86             else if(buf[i]) state = 7;
87             else            state>>=1; //2->1, 1->0, 0->0
88         }else if(state<=5){
89             int v= buf[i] & 0x1F;
90             if(v==6 || v==7 || v==8 || v==9){
91                 if(pc->frame_start_found){
92                     i++;
93                     goto found;
94                 }
95             }else if(v==1 || v==2 || v==5){
96                 state+=8;
97                 continue;
98             }
99             state= 7;
100         }else{
101             h->parse_history[h->parse_history_count++]= buf[i];
102             if(h->parse_history_count>3){
103                 unsigned int mb, last_mb= h->parse_last_mb;
104                 GetBitContext gb;
105
106                 init_get_bits(&gb, h->parse_history, 8*h->parse_history_count);
107                 h->parse_history_count=0;
108                 mb= get_ue_golomb_long(&gb);
109                 last_mb= h->parse_last_mb;
110                 h->parse_last_mb= mb;
111                 if(pc->frame_start_found){
112                     if(mb <= last_mb)
113                         goto found;
114                 }else
115                     pc->frame_start_found = 1;
116                 state= 7;
117             }
118         }
119     }
120     pc->state= state;
121     if(h->is_avc)
122         return next_avc;
123     return END_NOT_FOUND;
124
125 found:
126     pc->state=7;
127     pc->frame_start_found= 0;
128     if(h->is_avc)
129         return next_avc;
130     return i-(state&5) - 3*(state>7);
131 }
132
133 /**
134  * Parse NAL units of found picture and decode some basic information.
135  *
136  * @param s parser context.
137  * @param avctx codec context.
138  * @param buf buffer with field/frame data.
139  * @param buf_size size of the buffer.
140  */
141 static inline int parse_nal_units(AVCodecParserContext *s,
142                                   AVCodecContext *avctx,
143                                   const uint8_t *buf, int buf_size)
144 {
145     H264Context *h = s->priv_data;
146     const uint8_t *buf_end = buf + buf_size;
147     unsigned int pps_id;
148     unsigned int slice_type;
149     int state = -1;
150     const uint8_t *ptr;
151     int q264 = buf_size >=4 && !memcmp("Q264", buf, 4);
152
153     /* set some sane default values */
154     s->pict_type = AV_PICTURE_TYPE_I;
155     s->key_frame = 0;
156
157     h->avctx= avctx;
158     h->sei_recovery_frame_cnt = -1;
159     h->sei_dpb_output_delay         =  0;
160     h->sei_cpb_removal_delay        = -1;
161     h->sei_buffering_period_present =  0;
162
163     if (!buf_size)
164         return 0;
165
166     for(;;) {
167         int src_length, dst_length, consumed, nalsize = 0;
168         if (h->is_avc) {
169             int i;
170             if (h->nal_length_size >= buf_end - buf) break;
171             nalsize = 0;
172             for (i = 0; i < h->nal_length_size; i++)
173                 nalsize = (nalsize << 8) | *buf++;
174             if (nalsize <= 0 || nalsize > buf_end - buf) {
175                 av_log(h->avctx, AV_LOG_ERROR, "AVC: nal size %d\n", nalsize);
176                 break;
177             }
178             src_length = nalsize;
179         } else {
180         buf = avpriv_find_start_code(buf, buf_end, &state);
181         if(buf >= buf_end)
182             break;
183         --buf;
184         src_length = buf_end - buf;
185         }
186         switch (state & 0x1f) {
187         case NAL_SLICE:
188         case NAL_IDR_SLICE:
189             // Do not walk the whole buffer just to decode slice header
190             if (src_length > 20)
191                 src_length = 20;
192             break;
193         }
194         ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
195         if (ptr==NULL || dst_length < 0)
196             break;
197
198         init_get_bits(&h->gb, ptr, 8*dst_length);
199         switch(h->nal_unit_type) {
200         case NAL_SPS:
201             ff_h264_decode_seq_parameter_set(h);
202             break;
203         case NAL_PPS:
204             ff_h264_decode_picture_parameter_set(h, h->gb.size_in_bits);
205             break;
206         case NAL_SEI:
207             ff_h264_decode_sei(h);
208             break;
209         case NAL_IDR_SLICE:
210             s->key_frame = 1;
211             /* fall through */
212         case NAL_SLICE:
213             get_ue_golomb_long(&h->gb);  // skip first_mb_in_slice
214             slice_type = get_ue_golomb_31(&h->gb);
215             s->pict_type = golomb_to_pict_type[slice_type % 5];
216             if (h->sei_recovery_frame_cnt >= 0) {
217                 /* key frame, since recovery_frame_cnt is set */
218                 s->key_frame = 1;
219             }
220             pps_id= get_ue_golomb(&h->gb);
221             if(pps_id>=MAX_PPS_COUNT) {
222                 av_log(h->avctx, AV_LOG_ERROR, "pps_id out of range\n");
223                 return -1;
224             }
225             if(!h->pps_buffers[pps_id]) {
226                 av_log(h->avctx, AV_LOG_ERROR, "non-existing PPS referenced\n");
227                 return -1;
228             }
229             h->pps= *h->pps_buffers[pps_id];
230             if(!h->sps_buffers[h->pps.sps_id]) {
231                 av_log(h->avctx, AV_LOG_ERROR, "non-existing SPS referenced\n");
232                 return -1;
233             }
234             h->sps = *h->sps_buffers[h->pps.sps_id];
235             h->frame_num = get_bits(&h->gb, h->sps.log2_max_frame_num);
236
237             avctx->profile = ff_h264_get_profile(&h->sps);
238             avctx->level   = h->sps.level_idc;
239
240             if(h->sps.frame_mbs_only_flag){
241                 h->picture_structure= PICT_FRAME;
242             }else{
243                 if(get_bits1(&h->gb)) { //field_pic_flag
244                     h->picture_structure= PICT_TOP_FIELD + get_bits1(&h->gb); //bottom_field_flag
245                 } else {
246                     h->picture_structure= PICT_FRAME;
247                 }
248             }
249
250             if(h->sps.pic_struct_present_flag) {
251                 switch (h->sei_pic_struct) {
252                     case SEI_PIC_STRUCT_TOP_FIELD:
253                     case SEI_PIC_STRUCT_BOTTOM_FIELD:
254                         s->repeat_pict = 0;
255                         break;
256                     case SEI_PIC_STRUCT_FRAME:
257                     case SEI_PIC_STRUCT_TOP_BOTTOM:
258                     case SEI_PIC_STRUCT_BOTTOM_TOP:
259                         s->repeat_pict = 1;
260                         break;
261                     case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
262                     case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
263                         s->repeat_pict = 2;
264                         break;
265                     case SEI_PIC_STRUCT_FRAME_DOUBLING:
266                         s->repeat_pict = 3;
267                         break;
268                     case SEI_PIC_STRUCT_FRAME_TRIPLING:
269                         s->repeat_pict = 5;
270                         break;
271                     default:
272                         s->repeat_pict = h->picture_structure == PICT_FRAME ? 1 : 0;
273                         break;
274                 }
275             } else {
276                 s->repeat_pict = h->picture_structure == PICT_FRAME ? 1 : 0;
277             }
278
279             return 0; /* no need to evaluate the rest */
280         }
281         buf += h->is_avc ? nalsize : consumed;
282     }
283     if (q264)
284         return 0;
285     /* didn't find a picture! */
286     av_log(h->avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
287     return -1;
288 }
289
290 static int h264_parse(AVCodecParserContext *s,
291                       AVCodecContext *avctx,
292                       const uint8_t **poutbuf, int *poutbuf_size,
293                       const uint8_t *buf, int buf_size)
294 {
295     H264Context *h = s->priv_data;
296     ParseContext *pc = &h->parse_context;
297     int next;
298
299     if (!h->got_first) {
300         h->got_first = 1;
301         if (avctx->extradata_size) {
302             h->avctx = avctx;
303             // must be done like in decoder, otherwise opening the parser,
304             // letting it create extradata and then closing and opening again
305             // will cause has_b_frames to be always set.
306             // Note that estimate_timings_from_pts does exactly this.
307             if (!avctx->has_b_frames)
308                 h->low_delay = 1;
309             ff_h264_decode_extradata(h, avctx->extradata, avctx->extradata_size);
310         }
311     }
312
313     if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
314         next= buf_size;
315     }else{
316         next = h264_find_frame_end(h, buf, buf_size);
317
318         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
319             *poutbuf = NULL;
320             *poutbuf_size = 0;
321             return buf_size;
322         }
323
324         if(next<0 && next != END_NOT_FOUND){
325             av_assert1(pc->last_index + next >= 0 );
326             h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); // update state
327         }
328     }
329
330     parse_nal_units(s, avctx, buf, buf_size);
331
332     if (h->sei_cpb_removal_delay >= 0) {
333         s->dts_sync_point    = h->sei_buffering_period_present;
334         s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
335         s->pts_dts_delta     = h->sei_dpb_output_delay;
336     } else {
337         s->dts_sync_point    = INT_MIN;
338         s->dts_ref_dts_delta = INT_MIN;
339         s->pts_dts_delta     = INT_MIN;
340     }
341
342     if (s->flags & PARSER_FLAG_ONCE) {
343         s->flags &= PARSER_FLAG_COMPLETE_FRAMES;
344     }
345
346     *poutbuf = buf;
347     *poutbuf_size = buf_size;
348     return next;
349 }
350
351 static int h264_split(AVCodecContext *avctx,
352                       const uint8_t *buf, int buf_size)
353 {
354     int i;
355     uint32_t state = -1;
356     int has_sps= 0;
357
358     for(i=0; i<=buf_size; i++){
359         if((state&0xFFFFFF1F) == 0x107)
360             has_sps=1;
361 /*        if((state&0xFFFFFF1F) == 0x101 || (state&0xFFFFFF1F) == 0x102 || (state&0xFFFFFF1F) == 0x105){
362         }*/
363         if((state&0xFFFFFF00) == 0x100 && (state&0xFFFFFF1F) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){
364             if(has_sps){
365                 while(i>4 && buf[i-5]==0) i--;
366                 return i-4;
367             }
368         }
369         if (i<buf_size)
370             state= (state<<8) | buf[i];
371     }
372     return 0;
373 }
374
375 static void close(AVCodecParserContext *s)
376 {
377     H264Context *h = s->priv_data;
378     ParseContext *pc = &h->parse_context;
379
380     av_free(pc->buffer);
381     ff_h264_free_context(h);
382 }
383
384 static int init(AVCodecParserContext *s)
385 {
386     H264Context *h = s->priv_data;
387     h->thread_context[0] = h;
388     h->slice_context_count = 1;
389     return 0;
390 }
391
392 AVCodecParser ff_h264_parser = {
393     .codec_ids      = { AV_CODEC_ID_H264 },
394     .priv_data_size = sizeof(H264Context),
395     .parser_init    = init,
396     .parser_parse   = h264_parse,
397     .parser_close   = close,
398     .split          = h264_split,
399 };