utvideoenc: Add missing AV_ prefix to codec ID
[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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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 #include "parser.h"
29 #include "h264data.h"
30 #include "golomb.h"
31
32 #include <assert.h>
33
34
35 static int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
36 {
37     int i;
38     uint32_t state;
39     ParseContext *pc = &(h->s.parse_context);
40 //printf("first %02X%02X%02X%02X\n", buf[0], buf[1],buf[2],buf[3]);
41 //    mb_addr= pc->mb_addr - 1;
42     state= pc->state;
43     if(state>13)
44         state= 7;
45
46     for(i=0; i<buf_size; i++){
47         if(state==7){
48 #if HAVE_FAST_UNALIGNED
49         /* we check i<buf_size instead of i+3/7 because its simpler
50          * and there should be FF_INPUT_BUFFER_PADDING_SIZE bytes at the end
51          */
52 #    if HAVE_FAST_64BIT
53             while(i<buf_size && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
54                 i+=8;
55 #    else
56             while(i<buf_size && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
57                 i+=4;
58 #    endif
59 #endif
60             for(; i<buf_size; i++){
61                 if(!buf[i]){
62                     state=2;
63                     break;
64                 }
65             }
66         }else if(state<=2){
67             if(buf[i]==1)   state^= 5; //2->7, 1->4, 0->5
68             else if(buf[i]) state = 7;
69             else            state>>=1; //2->1, 1->0, 0->0
70         }else if(state<=5){
71             int v= buf[i] & 0x1F;
72             if(v==6 || v==7 || v==8 || v==9){
73                 if(pc->frame_start_found){
74                     i++;
75                     goto found;
76                 }
77             }else if(v==1 || v==2 || v==5){
78                 if(pc->frame_start_found){
79                     state+=8;
80                     continue;
81                 }else
82                     pc->frame_start_found = 1;
83             }
84             state= 7;
85         }else{
86             if(buf[i] & 0x80)
87                 goto found;
88             state= 7;
89         }
90     }
91     pc->state= state;
92     return END_NOT_FOUND;
93
94 found:
95     pc->state=7;
96     pc->frame_start_found= 0;
97     return i-(state&5);
98 }
99
100 /**
101  * Parse NAL units of found picture and decode some basic information.
102  *
103  * @param s parser context.
104  * @param avctx codec context.
105  * @param buf buffer with field/frame data.
106  * @param buf_size size of the buffer.
107  */
108 static inline int parse_nal_units(AVCodecParserContext *s,
109                                   AVCodecContext *avctx,
110                                   const uint8_t *buf, int buf_size)
111 {
112     H264Context *h = s->priv_data;
113     const uint8_t *buf_end = buf + buf_size;
114     unsigned int pps_id;
115     unsigned int slice_type;
116     int state = -1;
117     const uint8_t *ptr;
118
119     /* set some sane default values */
120     s->pict_type = AV_PICTURE_TYPE_I;
121     s->key_frame = 0;
122
123     h->s.avctx= avctx;
124     h->sei_recovery_frame_cnt = -1;
125     h->sei_dpb_output_delay         =  0;
126     h->sei_cpb_removal_delay        = -1;
127     h->sei_buffering_period_present =  0;
128
129     if (!buf_size)
130         return 0;
131
132     for(;;) {
133         int src_length, dst_length, consumed;
134         buf = avpriv_mpv_find_start_code(buf, buf_end, &state);
135         if(buf >= buf_end)
136             break;
137         --buf;
138         src_length = buf_end - buf;
139         switch (state & 0x1f) {
140         case NAL_SLICE:
141         case NAL_IDR_SLICE:
142             // Do not walk the whole buffer just to decode slice header
143             if (src_length > 20)
144                 src_length = 20;
145             break;
146         }
147         ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
148         if (ptr==NULL || dst_length < 0)
149             break;
150
151         init_get_bits(&h->s.gb, ptr, 8*dst_length);
152         switch(h->nal_unit_type) {
153         case NAL_SPS:
154             ff_h264_decode_seq_parameter_set(h);
155             break;
156         case NAL_PPS:
157             ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits);
158             break;
159         case NAL_SEI:
160             ff_h264_decode_sei(h);
161             break;
162         case NAL_IDR_SLICE:
163             s->key_frame = 1;
164             /* fall through */
165         case NAL_SLICE:
166             get_ue_golomb(&h->s.gb);  // skip first_mb_in_slice
167             slice_type = get_ue_golomb_31(&h->s.gb);
168             s->pict_type = golomb_to_pict_type[slice_type % 5];
169             if (h->sei_recovery_frame_cnt >= 0) {
170                 /* key frame, since recovery_frame_cnt is set */
171                 s->key_frame = 1;
172             }
173             pps_id= get_ue_golomb(&h->s.gb);
174             if(pps_id>=MAX_PPS_COUNT) {
175                 av_log(h->s.avctx, AV_LOG_ERROR, "pps_id out of range\n");
176                 return -1;
177             }
178             if(!h->pps_buffers[pps_id]) {
179                 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing PPS referenced\n");
180                 return -1;
181             }
182             h->pps= *h->pps_buffers[pps_id];
183             if(!h->sps_buffers[h->pps.sps_id]) {
184                 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS referenced\n");
185                 return -1;
186             }
187             h->sps = *h->sps_buffers[h->pps.sps_id];
188             h->frame_num = get_bits(&h->s.gb, h->sps.log2_max_frame_num);
189
190             avctx->profile = ff_h264_get_profile(&h->sps);
191             avctx->level   = h->sps.level_idc;
192
193             if(h->sps.frame_mbs_only_flag){
194                 h->s.picture_structure= PICT_FRAME;
195             }else{
196                 if(get_bits1(&h->s.gb)) { //field_pic_flag
197                     h->s.picture_structure= PICT_TOP_FIELD + get_bits1(&h->s.gb); //bottom_field_flag
198                 } else {
199                     h->s.picture_structure= PICT_FRAME;
200                 }
201             }
202
203             if(h->sps.pic_struct_present_flag) {
204                 switch (h->sei_pic_struct) {
205                     case SEI_PIC_STRUCT_TOP_FIELD:
206                     case SEI_PIC_STRUCT_BOTTOM_FIELD:
207                         s->repeat_pict = 0;
208                         break;
209                     case SEI_PIC_STRUCT_FRAME:
210                     case SEI_PIC_STRUCT_TOP_BOTTOM:
211                     case SEI_PIC_STRUCT_BOTTOM_TOP:
212                         s->repeat_pict = 1;
213                         break;
214                     case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
215                     case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
216                         s->repeat_pict = 2;
217                         break;
218                     case SEI_PIC_STRUCT_FRAME_DOUBLING:
219                         s->repeat_pict = 3;
220                         break;
221                     case SEI_PIC_STRUCT_FRAME_TRIPLING:
222                         s->repeat_pict = 5;
223                         break;
224                     default:
225                         s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
226                         break;
227                 }
228             } else {
229                 s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
230             }
231
232             return 0; /* no need to evaluate the rest */
233         }
234         buf += consumed;
235     }
236     /* didn't find a picture! */
237     av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit\n");
238     return -1;
239 }
240
241 static int h264_parse(AVCodecParserContext *s,
242                       AVCodecContext *avctx,
243                       const uint8_t **poutbuf, int *poutbuf_size,
244                       const uint8_t *buf, int buf_size)
245 {
246     H264Context *h = s->priv_data;
247     ParseContext *pc = &h->s.parse_context;
248     int next;
249
250     if (!h->got_first) {
251         h->got_first = 1;
252         if (avctx->extradata_size) {
253             h->s.avctx = avctx;
254             // must be done like in the decoder.
255             // otherwise opening the parser, creating extradata,
256             // and then closing and opening again
257             // will cause has_b_frames to be always set.
258             // NB: estimate_timings_from_pts behaves exactly like this.
259             if (!avctx->has_b_frames)
260                 h->s.low_delay = 1;
261             ff_h264_decode_extradata(h);
262         }
263     }
264
265     if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
266         next= buf_size;
267     }else{
268         next= ff_h264_find_frame_end(h, buf, buf_size);
269
270         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
271             *poutbuf = NULL;
272             *poutbuf_size = 0;
273             return buf_size;
274         }
275
276         if(next<0 && next != END_NOT_FOUND){
277             assert(pc->last_index + next >= 0 );
278             ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
279         }
280     }
281
282     parse_nal_units(s, avctx, buf, buf_size);
283
284     if (h->sei_cpb_removal_delay >= 0) {
285         s->dts_sync_point    = h->sei_buffering_period_present;
286         s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
287         s->pts_dts_delta     = h->sei_dpb_output_delay;
288     } else {
289         s->dts_sync_point    = INT_MIN;
290         s->dts_ref_dts_delta = INT_MIN;
291         s->pts_dts_delta     = INT_MIN;
292     }
293
294     if (s->flags & PARSER_FLAG_ONCE) {
295         s->flags &= PARSER_FLAG_COMPLETE_FRAMES;
296     }
297
298     *poutbuf = buf;
299     *poutbuf_size = buf_size;
300     return next;
301 }
302
303 static int h264_split(AVCodecContext *avctx,
304                       const uint8_t *buf, int buf_size)
305 {
306     int i;
307     uint32_t state = -1;
308     int has_sps= 0;
309
310     for(i=0; i<=buf_size; i++){
311         if((state&0xFFFFFF1F) == 0x107)
312             has_sps=1;
313 /*        if((state&0xFFFFFF1F) == 0x101 || (state&0xFFFFFF1F) == 0x102 || (state&0xFFFFFF1F) == 0x105){
314         }*/
315         if((state&0xFFFFFF00) == 0x100 && (state&0xFFFFFF1F) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){
316             if(has_sps){
317                 while(i>4 && buf[i-5]==0) i--;
318                 return i-4;
319             }
320         }
321         if (i<buf_size)
322             state= (state<<8) | buf[i];
323     }
324     return 0;
325 }
326
327 static void close(AVCodecParserContext *s)
328 {
329     H264Context *h = s->priv_data;
330     ParseContext *pc = &h->s.parse_context;
331
332     av_free(pc->buffer);
333     ff_h264_free_context(h);
334 }
335
336 static int init(AVCodecParserContext *s)
337 {
338     H264Context *h = s->priv_data;
339     h->thread_context[0] = h;
340     h->s.slice_context_count = 1;
341     return 0;
342 }
343
344 AVCodecParser ff_h264_parser = {
345     .codec_ids      = { AV_CODEC_ID_H264 },
346     .priv_data_size = sizeof(H264Context),
347     .parser_init    = init,
348     .parser_parse   = h264_parse,
349     .parser_close   = close,
350     .split          = h264_split,
351 };