2 * Audio and Video frame extraction
3 * Copyright (c) 2003 Fabrice Bellard
4 * Copyright (c) 2003 Michael Niedermayer
6 * This file is part of FFmpeg.
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.
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.
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
27 #include "libavutil/avassert.h"
28 #include "libavutil/atomic.h"
29 #include "libavutil/internal.h"
30 #include "libavutil/mem.h"
35 static AVCodecParser *av_first_parser = NULL;
37 AVCodecParser *av_parser_next(const AVCodecParser *p)
42 return av_first_parser;
45 void av_register_codec_parser(AVCodecParser *parser)
48 parser->next = av_first_parser;
49 } while (parser->next != avpriv_atomic_ptr_cas((void * volatile *)&av_first_parser, parser->next, parser));
52 AVCodecParserContext *av_parser_init(int codec_id)
54 AVCodecParserContext *s = NULL;
55 AVCodecParser *parser;
58 if (codec_id == AV_CODEC_ID_NONE)
61 for (parser = av_first_parser; parser; parser = parser->next) {
62 if (parser->codec_ids[0] == codec_id ||
63 parser->codec_ids[1] == codec_id ||
64 parser->codec_ids[2] == codec_id ||
65 parser->codec_ids[3] == codec_id ||
66 parser->codec_ids[4] == codec_id)
72 s = av_mallocz(sizeof(AVCodecParserContext));
76 s->priv_data = av_mallocz(parser->priv_data_size);
80 s->pict_type = AV_PICTURE_TYPE_I;
81 if (parser->parser_init) {
82 ret = parser->parser_init(s);
87 #if FF_API_CONVERGENCE_DURATION
88 FF_DISABLE_DEPRECATION_WARNINGS
89 s->convergence_duration = 0;
90 FF_ENABLE_DEPRECATION_WARNINGS
92 s->dts_sync_point = INT_MIN;
93 s->dts_ref_dts_delta = INT_MIN;
94 s->pts_dts_delta = INT_MIN;
101 av_freep(&s->priv_data);
106 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
112 s->pts = AV_NOPTS_VALUE;
116 for (i = 0; i < AV_PARSER_PTS_NB; i++) {
117 if (s->cur_offset + off >= s->cur_frame_offset[i] &&
118 (s->frame_offset < s->cur_frame_offset[i] ||
119 (!s->frame_offset && !s->next_frame_offset)) && // first field/frame
120 // check disabled since MPEG-TS does not send complete PES packets
121 /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){
123 if (!fuzzy || s->cur_frame_dts[i] != AV_NOPTS_VALUE) {
124 s->dts = s->cur_frame_dts[i];
125 s->pts = s->cur_frame_pts[i];
126 s->pos = s->cur_frame_pos[i];
127 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
130 s->cur_frame_offset[i] = INT64_MAX;
131 if (s->cur_offset + off < s->cur_frame_end[i])
137 int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx,
138 uint8_t **poutbuf, int *poutbuf_size,
139 const uint8_t *buf, int buf_size,
140 int64_t pts, int64_t dts, int64_t pos)
143 uint8_t dummy_buf[AV_INPUT_BUFFER_PADDING_SIZE];
145 av_assert1(avctx->codec_id != AV_CODEC_ID_NONE);
147 /* Parsers only work for the specified codec ids. */
148 av_assert1(avctx->codec_id == s->parser->codec_ids[0] ||
149 avctx->codec_id == s->parser->codec_ids[1] ||
150 avctx->codec_id == s->parser->codec_ids[2] ||
151 avctx->codec_id == s->parser->codec_ids[3] ||
152 avctx->codec_id == s->parser->codec_ids[4]);
154 if (!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
155 s->next_frame_offset =
157 s->flags |= PARSER_FLAG_FETCHED_OFFSET;
161 /* padding is always necessary even if EOF, so we add it here */
162 memset(dummy_buf, 0, sizeof(dummy_buf));
164 } else if (s->cur_offset + buf_size != s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
165 /* add a new packet descriptor */
166 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
167 s->cur_frame_start_index = i;
168 s->cur_frame_offset[i] = s->cur_offset;
169 s->cur_frame_end[i] = s->cur_offset + buf_size;
170 s->cur_frame_pts[i] = pts;
171 s->cur_frame_dts[i] = dts;
172 s->cur_frame_pos[i] = pos;
175 if (s->fetch_timestamp) {
176 s->fetch_timestamp = 0;
177 s->last_pts = s->pts;
178 s->last_dts = s->dts;
179 s->last_pos = s->pos;
180 ff_fetch_timestamp(s, 0, 0, 0);
182 /* WARNING: the returned index can be negative */
183 index = s->parser->parser_parse(s, avctx, (const uint8_t **) poutbuf,
184 poutbuf_size, buf, buf_size);
185 av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
186 #define FILL(name) if(s->name > 0 && avctx->name <= 0) avctx->name = s->name
187 if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
191 /* update the file pointer */
193 /* fill the data for the current frame */
194 s->frame_offset = s->next_frame_offset;
196 /* offset of the next frame */
197 s->next_frame_offset = s->cur_offset + index;
198 s->fetch_timestamp = 1;
202 s->cur_offset += index;
206 int av_parser_change(AVCodecParserContext *s, AVCodecContext *avctx,
207 uint8_t **poutbuf, int *poutbuf_size,
208 const uint8_t *buf, int buf_size, int keyframe)
210 if (s && s->parser->split) {
211 if (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER ||
212 avctx->flags2 & AV_CODEC_FLAG2_LOCAL_HEADER) {
213 int i = s->parser->split(avctx, buf, buf_size);
219 /* cast to avoid warning about discarding qualifiers */
220 *poutbuf = (uint8_t *) buf;
221 *poutbuf_size = buf_size;
222 if (avctx->extradata) {
223 if (keyframe && (avctx->flags2 & AV_CODEC_FLAG2_LOCAL_HEADER)) {
224 int size = buf_size + avctx->extradata_size;
226 *poutbuf_size = size;
227 *poutbuf = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
229 return AVERROR(ENOMEM);
231 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
232 memcpy(*poutbuf + avctx->extradata_size, buf,
233 buf_size + AV_INPUT_BUFFER_PADDING_SIZE);
241 void av_parser_close(AVCodecParserContext *s)
244 if (s->parser->parser_close)
245 s->parser->parser_close(s);
246 av_freep(&s->priv_data);
251 int ff_combine_frame(ParseContext *pc, int next,
252 const uint8_t **buf, int *buf_size)
255 ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
256 pc->overread, pc->state, next, pc->index, pc->overread_index);
257 ff_dlog(NULL, "%X %X %X %X\n",
258 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
261 /* Copy overread bytes from last frame into buffer. */
262 for (; pc->overread > 0; pc->overread--)
263 pc->buffer[pc->index++] = pc->buffer[pc->overread_index++];
265 /* flush remaining if EOF */
266 if (!*buf_size && next == END_NOT_FOUND)
269 pc->last_index = pc->index;
271 /* copy into buffer end return */
272 if (next == END_NOT_FOUND) {
273 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
274 *buf_size + pc->index +
275 AV_INPUT_BUFFER_PADDING_SIZE);
278 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", *buf_size + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
280 return AVERROR(ENOMEM);
282 pc->buffer = new_buffer;
283 memcpy(&pc->buffer[pc->index], *buf, *buf_size);
284 pc->index += *buf_size;
288 av_assert0(next >= 0 || pc->buffer);
291 pc->overread_index = pc->index + next;
293 /* append to buffer */
295 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
297 AV_INPUT_BUFFER_PADDING_SIZE);
299 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", next + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
302 return AVERROR(ENOMEM);
304 pc->buffer = new_buffer;
305 if (next > -AV_INPUT_BUFFER_PADDING_SIZE)
306 memcpy(&pc->buffer[pc->index], *buf,
307 next + AV_INPUT_BUFFER_PADDING_SIZE);
312 /* store overread bytes */
313 for (; next < 0; next++) {
314 pc->state = pc->state << 8 | pc->buffer[pc->last_index + next];
315 pc->state64 = pc->state64 << 8 | pc->buffer[pc->last_index + next];
320 ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
321 pc->overread, pc->state, next, pc->index, pc->overread_index);
322 ff_dlog(NULL, "%X %X %X %X\n",
323 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
329 void ff_parse_close(AVCodecParserContext *s)
331 ParseContext *pc = s->priv_data;
333 av_freep(&pc->buffer);
336 int ff_mpeg4video_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
339 const uint8_t *ptr = buf, *end = buf + buf_size;
342 ptr = avpriv_find_start_code(ptr, end, &state);
343 if (state == 0x1B3 || state == 0x1B6)
344 return ptr - 4 - buf;