4b2853708e6fb1184a672d18e7c8c8b4650c7c20
[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, int off, int remove){
80 int i;
81
82 s->dts= s->pts= AV_NOPTS_VALUE;
83 s->offset= 0;
84 for(i = 0; i < AV_PARSER_PTS_NB; i++) {
85 if ( s->next_frame_offset + off >= s->cur_frame_offset[i]
86 &&(s-> frame_offset < s->cur_frame_offset[i] || !s->frame_offset)
87 //check is disabled becausue mpeg-ts doesnt send complete PES packets
88 && /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){
89 s->dts= s->cur_frame_dts[i];
90 s->pts= s->cur_frame_pts[i];
91 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
92 if(remove)
93 s->cur_frame_offset[i]= INT64_MAX;
94 }
95 }
96 }
97
98 /**
99 *
100 * @param buf input
101 * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output)
102 * @param pts input presentation timestamp
103 * @param dts input decoding timestamp
104 * @param poutbuf will contain a pointer to the first byte of the output frame
105 * @param poutbuf_size will contain the length of the output frame
106 * @return the number of bytes of the input bitstream used
107 *
108 * Example:
109 * @code
110 * while(in_len){
111 * len = av_parser_parse(myparser, AVCodecContext, &data, &size,
112 * in_data, in_len,
113 * pts, dts);
114 * in_data += len;
115 * in_len -= len;
116 *
117 * if(size)
118 * decode_frame(data, size);
119 * }
120 * @endcode
121 */
122 int av_parser_parse(AVCodecParserContext *s,
123 AVCodecContext *avctx,
124 uint8_t **poutbuf, int *poutbuf_size,
125 const uint8_t *buf, int buf_size,
126 int64_t pts, int64_t dts)
127 {
128 int index, i;
129 uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
130
131 if (buf_size == 0) {
132 /* padding is always necessary even if EOF, so we add it here */
133 memset(dummy_buf, 0, sizeof(dummy_buf));
134 buf = dummy_buf;
135 } else {
136 /* add a new packet descriptor */
137 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
138 s->cur_frame_start_index = i;
139 s->cur_frame_offset[i] = s->cur_offset;
140 s->cur_frame_end[i] = s->cur_offset + buf_size;
141 s->cur_frame_pts[i] = pts;
142 s->cur_frame_dts[i] = dts;
143 }
144
145 if (s->fetch_timestamp){
146 s->fetch_timestamp=0;
147 s->last_pts = s->pts;
148 s->last_dts = s->dts;
149 ff_fetch_timestamp(s, 0, 0);
150 }
151
152 /* WARNING: the returned index can be negative */
153 index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size);
154 //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);
155 /* update the file pointer */
156 if (*poutbuf_size) {
157 /* fill the data for the current frame */
158 s->frame_offset = s->next_frame_offset;
159
160 /* offset of the next frame */
161 s->next_frame_offset = s->cur_offset + index;
162 s->fetch_timestamp=1;
163 }
164 if (index < 0)
165 index = 0;
166 s->cur_offset += index;
167 return index;
168 }
169
170 /**
171 *
172 * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
173 * @deprecated use AVBitstreamFilter
174 */
175 int av_parser_change(AVCodecParserContext *s,
176 AVCodecContext *avctx,
177 uint8_t **poutbuf, int *poutbuf_size,
178 const uint8_t *buf, int buf_size, int keyframe){
179
180 if(s && s->parser->split){
181 if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){
182 int i= s->parser->split(avctx, buf, buf_size);
183 buf += i;
184 buf_size -= i;
185 }
186 }
187
188 /* cast to avoid warning about discarding qualifiers */
189 *poutbuf= (uint8_t *) buf;
190 *poutbuf_size= buf_size;
191 if(avctx->extradata){
192 if( (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER))
193 /*||(s->pict_type != FF_I_TYPE && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/
194 /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
195 int size= buf_size + avctx->extradata_size;
196 *poutbuf_size= size;
197 *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
198
199 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
200 memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
201 return 1;
202 }
203 }
204
205 return 0;
206 }
207
208 void av_parser_close(AVCodecParserContext *s)
209 {
210 if(s){
211 if (s->parser->parser_close)
212 s->parser->parser_close(s);
213 av_free(s->priv_data);
214 av_free(s);
215 }
216 }
217
218 /*****************************************************/
219
220 /**
221 * combines the (truncated) bitstream to a complete frame
222 * @returns -1 if no complete frame could be created, AVERROR(ENOMEM) if there was a memory allocation error
223 */
224 int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
225 {
226 #if 0
227 if(pc->overread){
228 printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
229 printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
230 }
231 #endif
232
233 /* Copy overread bytes from last frame into buffer. */
234 for(; pc->overread>0; pc->overread--){
235 pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
236 }
237
238 /* flush remaining if EOF */
239 if(!*buf_size && next == END_NOT_FOUND){
240 next= 0;
241 }
242
243 pc->last_index= pc->index;
244
245 /* copy into buffer end return */
246 if(next == END_NOT_FOUND){
247 void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
248
249 if(!new_buffer)
250 return AVERROR(ENOMEM);
251 pc->buffer = new_buffer;
252 memcpy(&pc->buffer[pc->index], *buf, *buf_size);
253 pc->index += *buf_size;
254 return -1;
255 }
256
257 *buf_size=
258 pc->overread_index= pc->index + next;
259
260 /* append to buffer */
261 if(pc->index){
262 void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
263
264 if(!new_buffer)
265 return AVERROR(ENOMEM);
266 pc->buffer = new_buffer;
267 memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
268 pc->index = 0;
269 *buf= pc->buffer;
270 }
271
272 /* store overread bytes */
273 for(;next < 0; next++){
274 pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next];
275 pc->overread++;
276 }
277
278 #if 0
279 if(pc->overread){
280 printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
281 printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
282 }
283 #endif
284
285 return 0;
286 }
287
288 void ff_parse_close(AVCodecParserContext *s)
289 {
290 ParseContext *pc = s->priv_data;
291
292 av_free(pc->buffer);
293 }
294
295 void ff_parse1_close(AVCodecParserContext *s)
296 {
297 ParseContext1 *pc1 = s->priv_data;
298
299 av_free(pc1->pc.buffer);
300 av_free(pc1->enc);
301 }
302
303 /*************************/
304
305 int ff_mpeg4video_split(AVCodecContext *avctx,
306 const uint8_t *buf, int buf_size)
307 {
308 int i;
309 uint32_t state= -1;
310
311 for(i=0; i<buf_size; i++){
312 state= (state<<8) | buf[i];
313 if(state == 0x1B3 || state == 0x1B6)
314 return i-3;
315 }
316 return 0;
317 }