Change duration computation to use time_base instead of TB/2.
[libav.git] / libavcodec / h264_parser.c
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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
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20 */
21
22/**
bad5537e 23 * @file libavcodec/h264_parser.c
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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"
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30#include "h264data.h"
31#include "golomb.h"
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32
33#include <assert.h>
34
35
36int 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){
b250f9c6 49#if HAVE_FAST_UNALIGNED
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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 */
b250f9c6 53# if HAVE_FAST_64BIT
4d8eb2e8 54 while(i<buf_size && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
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55 i+=8;
56# else
4d8eb2e8 57 while(i<buf_size && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
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58 i+=4;
59# endif
60#endif
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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==7 || v==8 || v==9){
74 if(pc->frame_start_found){
75 i++;
9aa1cfec 76 goto found;
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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;
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94
95found:
96 pc->state=7;
97 pc->frame_start_found= 0;
98 return i-(state&5);
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99}
100
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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 */
109static 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;
96c3da93 115 unsigned int pps_id;
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116 unsigned int slice_type;
117 int state;
118 const uint8_t *ptr;
119
120 /* set some sane default values */
121 s->pict_type = FF_I_TYPE;
0ed260c7 122 s->key_frame = 0;
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123
124 h->s.avctx= avctx;
0ed260c7 125 h->sei_recovery_frame_cnt = -1;
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126
127 for(;;) {
128 int src_length, dst_length, consumed;
129 buf = ff_find_start_code(buf, buf_end, &state);
130 if(buf >= buf_end)
131 break;
132 --buf;
133 src_length = buf_end - buf;
134 switch (state & 0x1f) {
135 case NAL_SLICE:
136 case NAL_IDR_SLICE:
137 // Do not walk the whole buffer just to decode slice header
138 if (src_length > 20)
139 src_length = 20;
140 break;
141 }
142 ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
143 if (ptr==NULL || dst_length < 0)
144 break;
145
146 init_get_bits(&h->s.gb, ptr, 8*dst_length);
147 switch(h->nal_unit_type) {
148 case NAL_SPS:
149 ff_h264_decode_seq_parameter_set(h);
150 break;
151 case NAL_PPS:
152 ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits);
153 break;
154 case NAL_SEI:
155 ff_h264_decode_sei(h);
156 break;
157 case NAL_IDR_SLICE:
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158 s->key_frame = 1;
159 /* fall through */
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160 case NAL_SLICE:
161 get_ue_golomb(&h->s.gb); // skip first_mb_in_slice
162 slice_type = get_ue_golomb_31(&h->s.gb);
163 s->pict_type = golomb_to_pict_type[slice_type % 5];
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164 if (h->sei_recovery_frame_cnt >= 0) {
165 /* key frame, since recovery_frame_cnt is set */
166 s->key_frame = 1;
167 }
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168 pps_id= get_ue_golomb(&h->s.gb);
169 if(pps_id>=MAX_PPS_COUNT) {
170 av_log(h->s.avctx, AV_LOG_ERROR, "pps_id out of range\n");
171 return -1;
172 }
173 if(!h->pps_buffers[pps_id]) {
174 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing PPS referenced\n");
175 return -1;
176 }
177 h->pps= *h->pps_buffers[pps_id];
178 if(!h->sps_buffers[h->pps.sps_id]) {
179 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS referenced\n");
180 return -1;
181 }
182 h->sps = *h->sps_buffers[h->pps.sps_id];
183 h->frame_num = get_bits(&h->s.gb, h->sps.log2_max_frame_num);
184
185 if(h->sps.frame_mbs_only_flag){
186 h->s.picture_structure= PICT_FRAME;
187 }else{
188 if(get_bits1(&h->s.gb)) { //field_pic_flag
189 h->s.picture_structure= PICT_TOP_FIELD + get_bits1(&h->s.gb); //bottom_field_flag
190 } else {
191 h->s.picture_structure= PICT_FRAME;
192 }
193 }
194
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195 if(h->sps.pic_struct_present_flag) {
196 switch (h->sei_pic_struct) {
197 case SEI_PIC_STRUCT_TOP_FIELD:
198 case SEI_PIC_STRUCT_BOTTOM_FIELD:
199 s->repeat_pict = -1;
200 break;
201 case SEI_PIC_STRUCT_FRAME:
202 case SEI_PIC_STRUCT_TOP_BOTTOM:
203 case SEI_PIC_STRUCT_BOTTOM_TOP:
204 s->repeat_pict = 0;
205 break;
206 case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
207 case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
208 s->repeat_pict = 1;
209 break;
210 case SEI_PIC_STRUCT_FRAME_DOUBLING:
211 s->repeat_pict = 2;
212 break;
213 case SEI_PIC_STRUCT_FRAME_TRIPLING:
214 s->repeat_pict = 4;
215 break;
216 default:
217 s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 0 : -1;
218 break;
219 }
220 } else {
221 s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 0 : -1;
222 }
223
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224 return 0; /* no need to evaluate the rest */
225 }
226 buf += consumed;
227 }
228 /* didn't find a picture! */
229 av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit\n");
230 return -1;
231}
232
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233static int h264_parse(AVCodecParserContext *s,
234 AVCodecContext *avctx,
235 const uint8_t **poutbuf, int *poutbuf_size,
236 const uint8_t *buf, int buf_size)
237{
238 H264Context *h = s->priv_data;
239 ParseContext *pc = &h->s.parse_context;
240 int next;
241
242 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
243 next= buf_size;
244 }else{
245 next= ff_h264_find_frame_end(h, buf, buf_size);
246
247 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
248 *poutbuf = NULL;
249 *poutbuf_size = 0;
250 return buf_size;
251 }
252
253 if(next<0 && next != END_NOT_FOUND){
254 assert(pc->last_index + next >= 0 );
255 ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
256 }
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257
258 parse_nal_units(s, avctx, buf, buf_size);
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259 }
260
261 *poutbuf = buf;
262 *poutbuf_size = buf_size;
263 return next;
264}
265
266static int h264_split(AVCodecContext *avctx,
267 const uint8_t *buf, int buf_size)
268{
269 int i;
270 uint32_t state = -1;
271 int has_sps= 0;
272
273 for(i=0; i<=buf_size; i++){
274 if((state&0xFFFFFF1F) == 0x107)
275 has_sps=1;
276/* if((state&0xFFFFFF1F) == 0x101 || (state&0xFFFFFF1F) == 0x102 || (state&0xFFFFFF1F) == 0x105){
277 }*/
278 if((state&0xFFFFFF00) == 0x100 && (state&0xFFFFFF1F) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){
279 if(has_sps){
280 while(i>4 && buf[i-5]==0) i--;
281 return i-4;
282 }
283 }
284 if (i<buf_size)
285 state= (state<<8) | buf[i];
286 }
287 return 0;
288}
289
dd990075 290static void close(AVCodecParserContext *s)
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291{
292 H264Context *h = s->priv_data;
293 ParseContext *pc = &h->s.parse_context;
294
295 av_free(pc->buffer);
296}
297
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298
299AVCodecParser h264_parser = {
0d3d172f 300 { CODEC_ID_H264 },
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301 sizeof(H264Context),
302 NULL,
303 h264_parse,
3ee4f5e4 304 close,
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305 h264_split,
306};