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;
95 av_freep(&s->priv_data);
100 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
106 s->pts = AV_NOPTS_VALUE;
110 for (i = 0; i < AV_PARSER_PTS_NB; i++) {
111 if (s->cur_offset + off >= s->cur_frame_offset[i] &&
112 (s->frame_offset < s->cur_frame_offset[i] ||
113 (!s->frame_offset && !s->next_frame_offset)) && // first field/frame
114 // check disabled since MPEG-TS does not send complete PES packets
115 /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){
117 if (!fuzzy || s->cur_frame_dts[i] != AV_NOPTS_VALUE) {
118 s->dts = s->cur_frame_dts[i];
119 s->pts = s->cur_frame_pts[i];
120 s->pos = s->cur_frame_pos[i];
121 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
124 s->cur_frame_offset[i] = INT64_MAX;
125 if (s->cur_offset + off < s->cur_frame_end[i])
131 int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx,
132 uint8_t **poutbuf, int *poutbuf_size,
133 const uint8_t *buf, int buf_size,
134 int64_t pts, int64_t dts, int64_t pos)
137 uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
139 if (!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
140 s->next_frame_offset =
142 s->flags |= PARSER_FLAG_FETCHED_OFFSET;
146 /* padding is always necessary even if EOF, so we add it here */
147 memset(dummy_buf, 0, sizeof(dummy_buf));
149 } else if (s->cur_offset + buf_size != s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
150 /* add a new packet descriptor */
151 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
152 s->cur_frame_start_index = i;
153 s->cur_frame_offset[i] = s->cur_offset;
154 s->cur_frame_end[i] = s->cur_offset + buf_size;
155 s->cur_frame_pts[i] = pts;
156 s->cur_frame_dts[i] = dts;
157 s->cur_frame_pos[i] = pos;
160 if (s->fetch_timestamp) {
161 s->fetch_timestamp = 0;
162 s->last_pts = s->pts;
163 s->last_dts = s->dts;
164 s->last_pos = s->pos;
165 ff_fetch_timestamp(s, 0, 0, 0);
167 /* WARNING: the returned index can be negative */
168 index = s->parser->parser_parse(s, avctx, (const uint8_t **) poutbuf,
169 poutbuf_size, buf, buf_size);
170 av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
171 /* update the file pointer */
173 /* fill the data for the current frame */
174 s->frame_offset = s->next_frame_offset;
176 /* offset of the next frame */
177 s->next_frame_offset = s->cur_offset + index;
178 s->fetch_timestamp = 1;
182 s->cur_offset += index;
186 int av_parser_change(AVCodecParserContext *s, AVCodecContext *avctx,
187 uint8_t **poutbuf, int *poutbuf_size,
188 const uint8_t *buf, int buf_size, int keyframe)
190 if (s && s->parser->split) {
191 if (avctx->flags & CODEC_FLAG_GLOBAL_HEADER ||
192 avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER) {
193 int i = s->parser->split(avctx, buf, buf_size);
199 /* cast to avoid warning about discarding qualifiers */
200 *poutbuf = (uint8_t *) buf;
201 *poutbuf_size = buf_size;
202 if (avctx->extradata) {
203 if (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)) {
204 int size = buf_size + avctx->extradata_size;
206 *poutbuf_size = size;
207 *poutbuf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
209 return AVERROR(ENOMEM);
211 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
212 memcpy(*poutbuf + avctx->extradata_size, buf,
213 buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
221 void av_parser_close(AVCodecParserContext *s)
224 if (s->parser->parser_close)
225 s->parser->parser_close(s);
226 av_freep(&s->priv_data);
231 int ff_combine_frame(ParseContext *pc, int next,
232 const uint8_t **buf, int *buf_size)
235 ff_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
236 pc->overread, pc->state, next, pc->index, pc->overread_index);
237 ff_dlog(NULL, "%X %X %X %X\n",
238 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
241 /* Copy overread bytes from last frame into buffer. */
242 for (; pc->overread > 0; pc->overread--)
243 pc->buffer[pc->index++] = pc->buffer[pc->overread_index++];
245 /* flush remaining if EOF */
246 if (!*buf_size && next == END_NOT_FOUND)
249 pc->last_index = pc->index;
251 /* copy into buffer end return */
252 if (next == END_NOT_FOUND) {
253 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
254 *buf_size + pc->index +
255 FF_INPUT_BUFFER_PADDING_SIZE);
258 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", *buf_size + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
260 return AVERROR(ENOMEM);
262 pc->buffer = new_buffer;
263 memcpy(&pc->buffer[pc->index], *buf, *buf_size);
264 pc->index += *buf_size;
269 pc->overread_index = pc->index + next;
271 /* append to buffer */
273 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
275 FF_INPUT_BUFFER_PADDING_SIZE);
277 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
280 return AVERROR(ENOMEM);
282 pc->buffer = new_buffer;
283 if (next > -FF_INPUT_BUFFER_PADDING_SIZE)
284 memcpy(&pc->buffer[pc->index], *buf,
285 next + FF_INPUT_BUFFER_PADDING_SIZE);
290 /* store overread bytes */
291 for (; next < 0; next++) {
292 pc->state = pc->state << 8 | pc->buffer[pc->last_index + next];
293 pc->state64 = pc->state64 << 8 | pc->buffer[pc->last_index + next];
298 ff_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
299 pc->overread, pc->state, next, pc->index, pc->overread_index);
300 ff_dlog(NULL, "%X %X %X %X\n",
301 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
307 void ff_parse_close(AVCodecParserContext *s)
309 ParseContext *pc = s->priv_data;
311 av_freep(&pc->buffer);
314 int ff_mpeg4video_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
317 const uint8_t *ptr = buf, *end = buf + buf_size;
320 ptr = avpriv_find_start_code(ptr, end, &state);
321 if (state == 0x1B3 || state == 0x1B6)
322 return ptr - 4 - buf;