Factorize fetch_timestamp() into its own function
[libav.git] / libavcodec / parser.c
1 /*
2 * Audio and Video frame extraction
3 * Copyright (c) 2003 Fabrice Bellard.
4 * Copyright (c) 2003 Michael Niedermayer.
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "parser.h"
24
25 AVCodecParser *av_first_parser = NULL;
26
27 AVCodecParser* av_parser_next(AVCodecParser *p){
28 if(p) return p->next;
29 else return av_first_parser;
30 }
31
32 void av_register_codec_parser(AVCodecParser *parser)
33 {
34 parser->next = av_first_parser;
35 av_first_parser = parser;
36 }
37
38 AVCodecParserContext *av_parser_init(int codec_id)
39 {
40 AVCodecParserContext *s;
41 AVCodecParser *parser;
42 int ret;
43
44 if(codec_id == CODEC_ID_NONE)
45 return NULL;
46
47 for(parser = av_first_parser; parser != NULL; parser = parser->next) {
48 if (parser->codec_ids[0] == codec_id ||
49 parser->codec_ids[1] == codec_id ||
50 parser->codec_ids[2] == codec_id ||
51 parser->codec_ids[3] == codec_id ||
52 parser->codec_ids[4] == codec_id)
53 goto found;
54 }
55 return NULL;
56 found:
57 s = av_mallocz(sizeof(AVCodecParserContext));
58 if (!s)
59 return NULL;
60 s->parser = parser;
61 s->priv_data = av_mallocz(parser->priv_data_size);
62 if (!s->priv_data) {
63 av_free(s);
64 return NULL;
65 }
66 if (parser->parser_init) {
67 ret = parser->parser_init(s);
68 if (ret != 0) {
69 av_free(s->priv_data);
70 av_free(s);
71 return NULL;
72 }
73 }
74 s->fetch_timestamp=1;
75 s->pict_type = FF_I_TYPE;
76 return s;
77 }
78
79 void ff_fetch_timestamp(AVCodecParserContext *s){
80 int i;
81 s->dts= s->pts= AV_NOPTS_VALUE;
82 s->offset= 0;
83 for(i = 0; i < AV_PARSER_PTS_NB; i++) {
84 if ( s->next_frame_offset >= s->cur_frame_offset[i]
85 &&(s-> frame_offset < s->cur_frame_offset[i] || !s->frame_offset)
86 && s->next_frame_offset < s->cur_frame_end[i]){
87 s->dts= s->cur_frame_dts[i];
88 s->pts= s->cur_frame_pts[i];
89 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
90 }
91 }
92 }
93
94 /**
95 *
96 * @param buf input
97 * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output)
98 * @param pts input presentation timestamp
99 * @param dts input decoding timestamp
100 * @param poutbuf will contain a pointer to the first byte of the output frame
101 * @param poutbuf_size will contain the length of the output frame
102 * @return the number of bytes of the input bitstream used
103 *
104 * Example:
105 * @code
106 * while(in_len){
107 * len = av_parser_parse(myparser, AVCodecContext, &data, &size,
108 * in_data, in_len,
109 * pts, dts);
110 * in_data += len;
111 * in_len -= len;
112 *
113 * if(size)
114 * decode_frame(data, size);
115 * }
116 * @endcode
117 */
118 int av_parser_parse(AVCodecParserContext *s,
119 AVCodecContext *avctx,
120 uint8_t **poutbuf, int *poutbuf_size,
121 const uint8_t *buf, int buf_size,
122 int64_t pts, int64_t dts)
123 {
124 int index, i;
125 uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
126
127 if (buf_size == 0) {
128 /* padding is always necessary even if EOF, so we add it here */
129 memset(dummy_buf, 0, sizeof(dummy_buf));
130 buf = dummy_buf;
131 } else {
132 /* add a new packet descriptor */
133 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
134 s->cur_frame_start_index = i;
135 s->cur_frame_offset[i] = s->cur_offset;
136 s->cur_frame_end[i] = s->cur_offset + buf_size;
137 s->cur_frame_pts[i] = pts;
138 s->cur_frame_dts[i] = dts;
139 }
140
141 if (s->fetch_timestamp){
142 s->fetch_timestamp=0;
143 s->last_pts = s->pts;
144 s->last_dts = s->dts;
145 ff_fetch_timestamp(s);
146 }
147
148 /* WARNING: the returned index can be negative */
149 index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size);
150 //av_log(NULL, AV_LOG_DEBUG, "parser: in:%"PRId64", %"PRId64", out:%"PRId64", %"PRId64", in:%d out:%d id:%d\n", pts, dts, s->last_pts, s->last_dts, buf_size, *poutbuf_size, avctx->codec_id);
151 /* update the file pointer */
152 if (*poutbuf_size) {
153 /* fill the data for the current frame */
154 s->frame_offset = s->next_frame_offset;
155
156 /* offset of the next frame */
157 s->next_frame_offset = s->cur_offset + index;
158 s->fetch_timestamp=1;
159 }
160 if (index < 0)
161 index = 0;
162 s->cur_offset += index;
163 return index;
164 }
165
166 /**
167 *
168 * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
169 * @deprecated use AVBitstreamFilter
170 */
171 int av_parser_change(AVCodecParserContext *s,
172 AVCodecContext *avctx,
173 uint8_t **poutbuf, int *poutbuf_size,
174 const uint8_t *buf, int buf_size, int keyframe){
175
176 if(s && s->parser->split){
177 if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){
178 int i= s->parser->split(avctx, buf, buf_size);
179 buf += i;
180 buf_size -= i;
181 }
182 }
183
184 /* cast to avoid warning about discarding qualifiers */
185 *poutbuf= (uint8_t *) buf;
186 *poutbuf_size= buf_size;
187 if(avctx->extradata){
188 if( (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER))
189 /*||(s->pict_type != FF_I_TYPE && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/
190 /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
191 int size= buf_size + avctx->extradata_size;
192 *poutbuf_size= size;
193 *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
194
195 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
196 memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
197 return 1;
198 }
199 }
200
201 return 0;
202 }
203
204 void av_parser_close(AVCodecParserContext *s)
205 {
206 if(s){
207 if (s->parser->parser_close)
208 s->parser->parser_close(s);
209 av_free(s->priv_data);
210 av_free(s);
211 }
212 }
213
214 /*****************************************************/
215
216 /**
217 * combines the (truncated) bitstream to a complete frame
218 * @returns -1 if no complete frame could be created, AVERROR(ENOMEM) if there was a memory allocation error
219 */
220 int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
221 {
222 #if 0
223 if(pc->overread){
224 printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
225 printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
226 }
227 #endif
228
229 /* Copy overread bytes from last frame into buffer. */
230 for(; pc->overread>0; pc->overread--){
231 pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
232 }
233
234 /* flush remaining if EOF */
235 if(!*buf_size && next == END_NOT_FOUND){
236 next= 0;
237 }
238
239 pc->last_index= pc->index;
240
241 /* copy into buffer end return */
242 if(next == END_NOT_FOUND){
243 void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
244
245 if(!new_buffer)
246 return AVERROR(ENOMEM);
247 pc->buffer = new_buffer;
248 memcpy(&pc->buffer[pc->index], *buf, *buf_size);
249 pc->index += *buf_size;
250 return -1;
251 }
252
253 *buf_size=
254 pc->overread_index= pc->index + next;
255
256 /* append to buffer */
257 if(pc->index){
258 void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
259
260 if(!new_buffer)
261 return AVERROR(ENOMEM);
262 pc->buffer = new_buffer;
263 memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
264 pc->index = 0;
265 *buf= pc->buffer;
266 }
267
268 /* store overread bytes */
269 for(;next < 0; next++){
270 pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next];
271 pc->overread++;
272 }
273
274 #if 0
275 if(pc->overread){
276 printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
277 printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
278 }
279 #endif
280
281 return 0;
282 }
283
284 void ff_parse_close(AVCodecParserContext *s)
285 {
286 ParseContext *pc = s->priv_data;
287
288 av_free(pc->buffer);
289 }
290
291 void ff_parse1_close(AVCodecParserContext *s)
292 {
293 ParseContext1 *pc1 = s->priv_data;
294
295 av_free(pc1->pc.buffer);
296 av_free(pc1->enc);
297 }
298
299 /*************************/
300
301 int ff_mpeg4video_split(AVCodecContext *avctx,
302 const uint8_t *buf, int buf_size)
303 {
304 int i;
305 uint32_t state= -1;
306
307 for(i=0; i<buf_size; i++){
308 state= (state<<8) | buf[i];
309 if(state == 0x1B3 || state == 0x1B6)
310 return i-3;
311 }
312 return 0;
313 }