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
26 #include "libavutil/avassert.h"
27 #include "libavutil/atomic.h"
28 #include "libavutil/internal.h"
29 #include "libavutil/mem.h"
34 static AVCodecParser *av_first_parser = NULL;
36 AVCodecParser *av_parser_next(const AVCodecParser *p)
41 return av_first_parser;
44 void av_register_codec_parser(AVCodecParser *parser)
47 parser->next = av_first_parser;
48 } while (parser->next != avpriv_atomic_ptr_cas((void * volatile *)&av_first_parser, parser->next, parser));
51 AVCodecParserContext *av_parser_init(int codec_id)
53 AVCodecParserContext *s = NULL;
54 AVCodecParser *parser;
57 if (codec_id == AV_CODEC_ID_NONE)
60 for (parser = av_first_parser; parser; parser = parser->next) {
61 if (parser->codec_ids[0] == codec_id ||
62 parser->codec_ids[1] == codec_id ||
63 parser->codec_ids[2] == codec_id ||
64 parser->codec_ids[3] == codec_id ||
65 parser->codec_ids[4] == codec_id)
71 s = av_mallocz(sizeof(AVCodecParserContext));
75 s->priv_data = av_mallocz(parser->priv_data_size);
79 s->pict_type = AV_PICTURE_TYPE_I;
80 if (parser->parser_init) {
81 ret = parser->parser_init(s);
86 #if FF_API_CONVERGENCE_DURATION
87 FF_DISABLE_DEPRECATION_WARNINGS
88 s->convergence_duration = 0;
89 FF_ENABLE_DEPRECATION_WARNINGS
91 s->dts_sync_point = INT_MIN;
92 s->dts_ref_dts_delta = INT_MIN;
93 s->pts_dts_delta = INT_MIN;
100 av_freep(&s->priv_data);
105 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
111 s->pts = AV_NOPTS_VALUE;
115 for (i = 0; i < AV_PARSER_PTS_NB; i++) {
116 if (s->cur_offset + off >= s->cur_frame_offset[i] &&
117 (s->frame_offset < s->cur_frame_offset[i] ||
118 (!s->frame_offset && !s->next_frame_offset)) && // first field/frame
119 // check disabled since MPEG-TS does not send complete PES packets
120 /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){
122 if (!fuzzy || s->cur_frame_dts[i] != AV_NOPTS_VALUE) {
123 s->dts = s->cur_frame_dts[i];
124 s->pts = s->cur_frame_pts[i];
125 s->pos = s->cur_frame_pos[i];
126 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
129 s->cur_frame_offset[i] = INT64_MAX;
130 if (s->cur_offset + off < s->cur_frame_end[i])
136 int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx,
137 uint8_t **poutbuf, int *poutbuf_size,
138 const uint8_t *buf, int buf_size,
139 int64_t pts, int64_t dts, int64_t pos)
142 uint8_t dummy_buf[AV_INPUT_BUFFER_PADDING_SIZE];
144 av_assert1(avctx->codec_id != AV_CODEC_ID_NONE);
146 /* Parsers only work for the specified codec ids. */
147 av_assert1(avctx->codec_id == s->parser->codec_ids[0] ||
148 avctx->codec_id == s->parser->codec_ids[1] ||
149 avctx->codec_id == s->parser->codec_ids[2] ||
150 avctx->codec_id == s->parser->codec_ids[3] ||
151 avctx->codec_id == s->parser->codec_ids[4]);
153 if (!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
154 s->next_frame_offset =
156 s->flags |= PARSER_FLAG_FETCHED_OFFSET;
160 /* padding is always necessary even if EOF, so we add it here */
161 memset(dummy_buf, 0, sizeof(dummy_buf));
163 } else if (s->cur_offset + buf_size != s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
164 /* add a new packet descriptor */
165 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
166 s->cur_frame_start_index = i;
167 s->cur_frame_offset[i] = s->cur_offset;
168 s->cur_frame_end[i] = s->cur_offset + buf_size;
169 s->cur_frame_pts[i] = pts;
170 s->cur_frame_dts[i] = dts;
171 s->cur_frame_pos[i] = pos;
174 if (s->fetch_timestamp) {
175 s->fetch_timestamp = 0;
176 s->last_pts = s->pts;
177 s->last_dts = s->dts;
178 s->last_pos = s->pos;
179 ff_fetch_timestamp(s, 0, 0, 0);
181 /* WARNING: the returned index can be negative */
182 index = s->parser->parser_parse(s, avctx, (const uint8_t **) poutbuf,
183 poutbuf_size, buf, buf_size);
184 av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
185 /* update the file pointer */
187 /* fill the data for the current frame */
188 s->frame_offset = s->next_frame_offset;
190 /* offset of the next frame */
191 s->next_frame_offset = s->cur_offset + index;
192 s->fetch_timestamp = 1;
196 s->cur_offset += index;
200 int av_parser_change(AVCodecParserContext *s, AVCodecContext *avctx,
201 uint8_t **poutbuf, int *poutbuf_size,
202 const uint8_t *buf, int buf_size, int keyframe)
204 if (s && s->parser->split) {
205 if (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER ||
206 avctx->flags2 & AV_CODEC_FLAG2_LOCAL_HEADER) {
207 int i = s->parser->split(avctx, buf, buf_size);
213 /* cast to avoid warning about discarding qualifiers */
214 *poutbuf = (uint8_t *) buf;
215 *poutbuf_size = buf_size;
216 if (avctx->extradata) {
217 if (keyframe && (avctx->flags2 & AV_CODEC_FLAG2_LOCAL_HEADER)) {
218 int size = buf_size + avctx->extradata_size;
220 *poutbuf_size = size;
221 *poutbuf = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
223 return AVERROR(ENOMEM);
225 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
226 memcpy(*poutbuf + avctx->extradata_size, buf,
227 buf_size + AV_INPUT_BUFFER_PADDING_SIZE);
235 void av_parser_close(AVCodecParserContext *s)
238 if (s->parser->parser_close)
239 s->parser->parser_close(s);
240 av_freep(&s->priv_data);
245 int ff_combine_frame(ParseContext *pc, int next,
246 const uint8_t **buf, int *buf_size)
249 ff_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
250 pc->overread, pc->state, next, pc->index, pc->overread_index);
251 ff_dlog(NULL, "%X %X %X %X\n",
252 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
255 /* Copy overread bytes from last frame into buffer. */
256 for (; pc->overread > 0; pc->overread--)
257 pc->buffer[pc->index++] = pc->buffer[pc->overread_index++];
259 /* flush remaining if EOF */
260 if (!*buf_size && next == END_NOT_FOUND)
263 pc->last_index = pc->index;
265 /* copy into buffer end return */
266 if (next == END_NOT_FOUND) {
267 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
268 *buf_size + pc->index +
269 AV_INPUT_BUFFER_PADDING_SIZE);
272 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", *buf_size + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
274 return AVERROR(ENOMEM);
276 pc->buffer = new_buffer;
277 memcpy(&pc->buffer[pc->index], *buf, *buf_size);
278 pc->index += *buf_size;
283 pc->overread_index = pc->index + next;
285 /* append to buffer */
287 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
289 AV_INPUT_BUFFER_PADDING_SIZE);
291 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", next + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
294 return AVERROR(ENOMEM);
296 pc->buffer = new_buffer;
297 if (next > -AV_INPUT_BUFFER_PADDING_SIZE)
298 memcpy(&pc->buffer[pc->index], *buf,
299 next + AV_INPUT_BUFFER_PADDING_SIZE);
304 /* store overread bytes */
305 for (; next < 0; next++) {
306 pc->state = pc->state << 8 | pc->buffer[pc->last_index + next];
307 pc->state64 = pc->state64 << 8 | pc->buffer[pc->last_index + next];
312 ff_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
313 pc->overread, pc->state, next, pc->index, pc->overread_index);
314 ff_dlog(NULL, "%X %X %X %X\n",
315 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
321 void ff_parse_close(AVCodecParserContext *s)
323 ParseContext *pc = s->priv_data;
325 av_freep(&pc->buffer);
328 int ff_mpeg4video_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
331 const uint8_t *ptr = buf, *end = buf + buf_size;
334 ptr = avpriv_find_start_code(ptr, end, &state);
335 if (state == 0x1B3 || state == 0x1B6)
336 return ptr - 4 - buf;