Initialize thread_context[0] with h264 parser context.
[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 libavcodec/h264_parser.c
24  * H.264 / AVC / MPEG4 part10 parser.
25  * @author Michael Niedermayer <michaelni@gmx.at>
26  */
27
28 #include "parser.h"
29 #include "h264_parser.h"
30 #include "h264data.h"
31 #include "golomb.h"
32
33 #include <assert.h>
34
35
36 int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
37 {
38     int i;
39     uint32_t state;
40     ParseContext *pc = &(h->s.parse_context);
41 //printf("first %02X%02X%02X%02X\n", buf[0], buf[1],buf[2],buf[3]);
42 //    mb_addr= pc->mb_addr - 1;
43     state= pc->state;
44     if(state>13)
45         state= 7;
46
47     for(i=0; i<buf_size; i++){
48         if(state==7){
49 #if HAVE_FAST_UNALIGNED
50         /* we check i<buf_size instead of i+3/7 because its simpler
51          * and there should be FF_INPUT_BUFFER_PADDING_SIZE bytes at the end
52          */
53 #    if HAVE_FAST_64BIT
54             while(i<buf_size && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
55                 i+=8;
56 #    else
57             while(i<buf_size && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
58                 i+=4;
59 #    endif
60 #endif
61             for(; i<buf_size; i++){
62                 if(!buf[i]){
63                     state=2;
64                     break;
65                 }
66             }
67         }else if(state<=2){
68             if(buf[i]==1)   state^= 5; //2->7, 1->4, 0->5
69             else if(buf[i]) state = 7;
70             else            state>>=1; //2->1, 1->0, 0->0
71         }else if(state<=5){
72             int v= buf[i] & 0x1F;
73             if(v==6 || v==7 || v==8 || v==9){
74                 if(pc->frame_start_found){
75                     i++;
76                     goto found;
77                 }
78             }else if(v==1 || v==2 || v==5){
79                 if(pc->frame_start_found){
80                     state+=8;
81                     continue;
82                 }else
83                     pc->frame_start_found = 1;
84             }
85             state= 7;
86         }else{
87             if(buf[i] & 0x80)
88                 goto found;
89             state= 7;
90         }
91     }
92     pc->state= state;
93     return END_NOT_FOUND;
94
95 found:
96     pc->state=7;
97     pc->frame_start_found= 0;
98     return i-(state&5);
99 }
100
101 /*!
102  * Parse NAL units of found picture and decode some basic information.
103  *
104  * @param s parser context.
105  * @param avctx codec context.
106  * @param buf buffer with field/frame data.
107  * @param buf_size size of the buffer.
108  */
109 static inline int parse_nal_units(AVCodecParserContext *s,
110                                   AVCodecContext *avctx,
111                                   const uint8_t *buf, int buf_size)
112 {
113     H264Context *h = s->priv_data;
114     const uint8_t *buf_end = buf + buf_size;
115     unsigned int pps_id;
116     unsigned int slice_type;
117     int state = -1;
118     const uint8_t *ptr;
119
120     /* set some sane default values */
121     s->pict_type = FF_I_TYPE;
122     s->key_frame = 0;
123
124     h->s.avctx= avctx;
125     h->sei_recovery_frame_cnt = -1;
126     h->sei_dpb_output_delay         =  0;
127     h->sei_cpb_removal_delay        = -1;
128     h->sei_buffering_period_present =  0;
129
130     for(;;) {
131         int src_length, dst_length, consumed;
132         buf = ff_find_start_code(buf, buf_end, &state);
133         if(buf >= buf_end)
134             break;
135         --buf;
136         src_length = buf_end - buf;
137         switch (state & 0x1f) {
138         case NAL_SLICE:
139         case NAL_IDR_SLICE:
140             // Do not walk the whole buffer just to decode slice header
141             if (src_length > 20)
142                 src_length = 20;
143             break;
144         }
145         ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
146         if (ptr==NULL || dst_length < 0)
147             break;
148
149         init_get_bits(&h->s.gb, ptr, 8*dst_length);
150         switch(h->nal_unit_type) {
151         case NAL_SPS:
152             ff_h264_decode_seq_parameter_set(h);
153             break;
154         case NAL_PPS:
155             ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits);
156             break;
157         case NAL_SEI:
158             ff_h264_decode_sei(h);
159             break;
160         case NAL_IDR_SLICE:
161             s->key_frame = 1;
162             /* fall through */
163         case NAL_SLICE:
164             get_ue_golomb(&h->s.gb);  // skip first_mb_in_slice
165             slice_type = get_ue_golomb_31(&h->s.gb);
166             s->pict_type = golomb_to_pict_type[slice_type % 5];
167             if (h->sei_recovery_frame_cnt >= 0) {
168                 /* key frame, since recovery_frame_cnt is set */
169                 s->key_frame = 1;
170             }
171             pps_id= get_ue_golomb(&h->s.gb);
172             if(pps_id>=MAX_PPS_COUNT) {
173                 av_log(h->s.avctx, AV_LOG_ERROR, "pps_id out of range\n");
174                 return -1;
175             }
176             if(!h->pps_buffers[pps_id]) {
177                 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing PPS referenced\n");
178                 return -1;
179             }
180             h->pps= *h->pps_buffers[pps_id];
181             if(!h->sps_buffers[h->pps.sps_id]) {
182                 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS referenced\n");
183                 return -1;
184             }
185             h->sps = *h->sps_buffers[h->pps.sps_id];
186             h->frame_num = get_bits(&h->s.gb, h->sps.log2_max_frame_num);
187
188             if(h->sps.frame_mbs_only_flag){
189                 h->s.picture_structure= PICT_FRAME;
190             }else{
191                 if(get_bits1(&h->s.gb)) { //field_pic_flag
192                     h->s.picture_structure= PICT_TOP_FIELD + get_bits1(&h->s.gb); //bottom_field_flag
193                 } else {
194                     h->s.picture_structure= PICT_FRAME;
195                 }
196             }
197
198             if(h->sps.pic_struct_present_flag) {
199                 switch (h->sei_pic_struct) {
200                     case SEI_PIC_STRUCT_TOP_FIELD:
201                     case SEI_PIC_STRUCT_BOTTOM_FIELD:
202                         s->repeat_pict = 0;
203                         break;
204                     case SEI_PIC_STRUCT_FRAME:
205                     case SEI_PIC_STRUCT_TOP_BOTTOM:
206                     case SEI_PIC_STRUCT_BOTTOM_TOP:
207                         s->repeat_pict = 1;
208                         break;
209                     case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
210                     case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
211                         s->repeat_pict = 2;
212                         break;
213                     case SEI_PIC_STRUCT_FRAME_DOUBLING:
214                         s->repeat_pict = 3;
215                         break;
216                     case SEI_PIC_STRUCT_FRAME_TRIPLING:
217                         s->repeat_pict = 5;
218                         break;
219                     default:
220                         s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
221                         break;
222                 }
223             } else {
224                 s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
225             }
226
227             return 0; /* no need to evaluate the rest */
228         }
229         buf += consumed;
230     }
231     /* didn't find a picture! */
232     av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit\n");
233     return -1;
234 }
235
236 static int h264_parse(AVCodecParserContext *s,
237                       AVCodecContext *avctx,
238                       const uint8_t **poutbuf, int *poutbuf_size,
239                       const uint8_t *buf, int buf_size)
240 {
241     H264Context *h = s->priv_data;
242     ParseContext *pc = &h->s.parse_context;
243     int next;
244
245     if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
246         next= buf_size;
247     }else{
248         next= ff_h264_find_frame_end(h, buf, buf_size);
249
250         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
251             *poutbuf = NULL;
252             *poutbuf_size = 0;
253             return buf_size;
254         }
255
256         if(next<0 && next != END_NOT_FOUND){
257             assert(pc->last_index + next >= 0 );
258             ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
259         }
260
261         parse_nal_units(s, avctx, buf, buf_size);
262
263         if (h->sei_cpb_removal_delay >= 0) {
264             s->dts_sync_point    = h->sei_buffering_period_present;
265             s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
266             s->pts_dts_delta     = h->sei_dpb_output_delay;
267         } else {
268             s->dts_sync_point    = INT_MIN;
269             s->dts_ref_dts_delta = INT_MIN;
270             s->pts_dts_delta     = INT_MIN;
271         }
272     }
273
274     *poutbuf = buf;
275     *poutbuf_size = buf_size;
276     return next;
277 }
278
279 static int h264_split(AVCodecContext *avctx,
280                       const uint8_t *buf, int buf_size)
281 {
282     int i;
283     uint32_t state = -1;
284     int has_sps= 0;
285
286     for(i=0; i<=buf_size; i++){
287         if((state&0xFFFFFF1F) == 0x107)
288             has_sps=1;
289 /*        if((state&0xFFFFFF1F) == 0x101 || (state&0xFFFFFF1F) == 0x102 || (state&0xFFFFFF1F) == 0x105){
290         }*/
291         if((state&0xFFFFFF00) == 0x100 && (state&0xFFFFFF1F) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){
292             if(has_sps){
293                 while(i>4 && buf[i-5]==0) i--;
294                 return i-4;
295             }
296         }
297         if (i<buf_size)
298             state= (state<<8) | buf[i];
299     }
300     return 0;
301 }
302
303 static void close(AVCodecParserContext *s)
304 {
305     H264Context *h = s->priv_data;
306     ParseContext *pc = &h->s.parse_context;
307
308     av_free(pc->buffer);
309     ff_h264_free_context(h);
310 }
311
312 static int init(AVCodecParserContext *s)
313 {
314     H264Context *h = s->priv_data;
315     h->thread_context[0] = h;
316     return 0;
317 }
318
319 AVCodecParser h264_parser = {
320     { CODEC_ID_H264 },
321     sizeof(H264Context),
322     init,
323     h264_parse,
324     close,
325     h264_split,
326 };