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/mem.h"
33 static AVCodecParser *av_first_parser = NULL;
35 AVCodecParser *av_parser_next(const AVCodecParser *p)
40 return av_first_parser;
43 void av_register_codec_parser(AVCodecParser *parser)
46 parser->next = av_first_parser;
47 } while (parser->next != avpriv_atomic_ptr_cas((void * volatile *)&av_first_parser, parser->next, parser));
50 AVCodecParserContext *av_parser_init(int codec_id)
52 AVCodecParserContext *s = NULL;
53 AVCodecParser *parser;
56 if (codec_id == AV_CODEC_ID_NONE)
59 for (parser = av_first_parser; parser; parser = parser->next) {
60 if (parser->codec_ids[0] == codec_id ||
61 parser->codec_ids[1] == codec_id ||
62 parser->codec_ids[2] == codec_id ||
63 parser->codec_ids[3] == codec_id ||
64 parser->codec_ids[4] == codec_id)
70 s = av_mallocz(sizeof(AVCodecParserContext));
74 s->priv_data = av_mallocz(parser->priv_data_size);
78 s->pict_type = AV_PICTURE_TYPE_I;
79 if (parser->parser_init) {
80 ret = parser->parser_init(s);
85 s->convergence_duration = 0;
86 s->dts_sync_point = INT_MIN;
87 s->dts_ref_dts_delta = INT_MIN;
88 s->pts_dts_delta = INT_MIN;
93 av_freep(&s->priv_data);
98 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
104 s->pts = AV_NOPTS_VALUE;
108 for (i = 0; i < AV_PARSER_PTS_NB; i++) {
109 if (s->cur_offset + off >= s->cur_frame_offset[i] &&
110 (s->frame_offset < s->cur_frame_offset[i] ||
111 (!s->frame_offset && !s->next_frame_offset)) && // first field/frame
112 // check disabled since MPEG-TS does not send complete PES packets
113 /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){
115 if (!fuzzy || s->cur_frame_dts[i] != AV_NOPTS_VALUE) {
116 s->dts = s->cur_frame_dts[i];
117 s->pts = s->cur_frame_pts[i];
118 s->pos = s->cur_frame_pos[i];
119 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
122 s->cur_frame_offset[i] = INT64_MAX;
123 if (s->cur_offset + off < s->cur_frame_end[i])
129 int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx,
130 uint8_t **poutbuf, int *poutbuf_size,
131 const uint8_t *buf, int buf_size,
132 int64_t pts, int64_t dts, int64_t pos)
135 uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
137 if (!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
138 s->next_frame_offset =
140 s->flags |= PARSER_FLAG_FETCHED_OFFSET;
144 /* padding is always necessary even if EOF, so we add it here */
145 memset(dummy_buf, 0, sizeof(dummy_buf));
147 } else if (s->cur_offset + buf_size != s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
148 /* add a new packet descriptor */
149 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
150 s->cur_frame_start_index = i;
151 s->cur_frame_offset[i] = s->cur_offset;
152 s->cur_frame_end[i] = s->cur_offset + buf_size;
153 s->cur_frame_pts[i] = pts;
154 s->cur_frame_dts[i] = dts;
155 s->cur_frame_pos[i] = pos;
158 if (s->fetch_timestamp) {
159 s->fetch_timestamp = 0;
160 s->last_pts = s->pts;
161 s->last_dts = s->dts;
162 s->last_pos = s->pos;
163 ff_fetch_timestamp(s, 0, 0, 0);
165 /* WARNING: the returned index can be negative */
166 index = s->parser->parser_parse(s, avctx, (const uint8_t **) poutbuf,
167 poutbuf_size, buf, buf_size);
168 av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
169 /* update the file pointer */
171 /* fill the data for the current frame */
172 s->frame_offset = s->next_frame_offset;
174 /* offset of the next frame */
175 s->next_frame_offset = s->cur_offset + index;
176 s->fetch_timestamp = 1;
180 s->cur_offset += index;
184 int av_parser_change(AVCodecParserContext *s, AVCodecContext *avctx,
185 uint8_t **poutbuf, int *poutbuf_size,
186 const uint8_t *buf, int buf_size, int keyframe)
188 if (s && s->parser->split) {
189 if (avctx->flags & CODEC_FLAG_GLOBAL_HEADER ||
190 avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER) {
191 int i = s->parser->split(avctx, buf, buf_size);
197 /* cast to avoid warning about discarding qualifiers */
198 *poutbuf = (uint8_t *) buf;
199 *poutbuf_size = buf_size;
200 if (avctx->extradata) {
201 if (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)) {
202 int size = buf_size + avctx->extradata_size;
204 *poutbuf_size = size;
205 *poutbuf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
207 return AVERROR(ENOMEM);
209 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
210 memcpy(*poutbuf + avctx->extradata_size, buf,
211 buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
219 void av_parser_close(AVCodecParserContext *s)
222 if (s->parser->parser_close)
223 s->parser->parser_close(s);
224 av_freep(&s->priv_data);
229 int ff_combine_frame(ParseContext *pc, int next,
230 const uint8_t **buf, int *buf_size)
233 av_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
234 pc->overread, pc->state, next, pc->index, pc->overread_index);
235 av_dlog(NULL, "%X %X %X %X\n",
236 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
239 /* Copy overread bytes from last frame into buffer. */
240 for (; pc->overread > 0; pc->overread--)
241 pc->buffer[pc->index++] = pc->buffer[pc->overread_index++];
243 /* flush remaining if EOF */
244 if (!*buf_size && next == END_NOT_FOUND)
247 pc->last_index = pc->index;
249 /* copy into buffer end return */
250 if (next == END_NOT_FOUND) {
251 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
252 *buf_size + pc->index +
253 FF_INPUT_BUFFER_PADDING_SIZE);
257 return AVERROR(ENOMEM);
259 pc->buffer = new_buffer;
260 memcpy(&pc->buffer[pc->index], *buf, *buf_size);
261 pc->index += *buf_size;
266 pc->overread_index = pc->index + next;
268 /* append to buffer */
270 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
272 FF_INPUT_BUFFER_PADDING_SIZE);
276 return AVERROR(ENOMEM);
278 pc->buffer = new_buffer;
279 if (next > -FF_INPUT_BUFFER_PADDING_SIZE)
280 memcpy(&pc->buffer[pc->index], *buf,
281 next + FF_INPUT_BUFFER_PADDING_SIZE);
286 /* store overread bytes */
287 for (; next < 0; next++) {
288 pc->state = pc->state << 8 | pc->buffer[pc->last_index + next];
289 pc->state64 = pc->state64 << 8 | pc->buffer[pc->last_index + next];
294 av_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
295 pc->overread, pc->state, next, pc->index, pc->overread_index);
296 av_dlog(NULL, "%X %X %X %X\n",
297 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
303 void ff_parse_close(AVCodecParserContext *s)
305 ParseContext *pc = s->priv_data;
307 av_freep(&pc->buffer);
310 int ff_mpeg4video_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
313 const uint8_t *ptr = buf, *end = buf + buf_size;
316 ptr = avpriv_find_start_code(ptr, end, &state);
317 if (state == 0x1B3 || state == 0x1B6)
318 return ptr - 4 - buf;