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/internal.h"
29 #include "libavutil/mem.h"
34 AVCodecParserContext *av_parser_init(int codec_id)
36 AVCodecParserContext *s = NULL;
37 const AVCodecParser *parser;
41 if (codec_id == AV_CODEC_ID_NONE)
44 while ((parser = av_parser_iterate(&i))) {
45 if (parser->codec_ids[0] == codec_id ||
46 parser->codec_ids[1] == codec_id ||
47 parser->codec_ids[2] == codec_id ||
48 parser->codec_ids[3] == codec_id ||
49 parser->codec_ids[4] == codec_id)
55 s = av_mallocz(sizeof(AVCodecParserContext));
58 s->parser = (AVCodecParser*)parser;
59 s->priv_data = av_mallocz(parser->priv_data_size);
63 s->pict_type = AV_PICTURE_TYPE_I;
64 if (parser->parser_init) {
65 ret = parser->parser_init(s);
70 s->dts_sync_point = INT_MIN;
71 s->dts_ref_dts_delta = INT_MIN;
72 s->pts_dts_delta = INT_MIN;
79 av_freep(&s->priv_data);
84 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
90 s->pts = AV_NOPTS_VALUE;
94 for (i = 0; i < AV_PARSER_PTS_NB; i++) {
95 if (s->cur_offset + off >= s->cur_frame_offset[i] &&
96 (s->frame_offset < s->cur_frame_offset[i] ||
97 (!s->frame_offset && !s->next_frame_offset)) && // first field/frame
98 // check disabled since MPEG-TS does not send complete PES packets
99 /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){
101 if (!fuzzy || s->cur_frame_dts[i] != AV_NOPTS_VALUE) {
102 s->dts = s->cur_frame_dts[i];
103 s->pts = s->cur_frame_pts[i];
104 s->pos = s->cur_frame_pos[i];
105 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
108 s->cur_frame_offset[i] = INT64_MAX;
109 if (s->cur_offset + off < s->cur_frame_end[i])
115 int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx,
116 uint8_t **poutbuf, int *poutbuf_size,
117 const uint8_t *buf, int buf_size,
118 int64_t pts, int64_t dts, int64_t pos)
121 uint8_t dummy_buf[AV_INPUT_BUFFER_PADDING_SIZE];
123 av_assert1(avctx->codec_id != AV_CODEC_ID_NONE);
125 /* Parsers only work for the specified codec ids. */
126 av_assert1(avctx->codec_id == s->parser->codec_ids[0] ||
127 avctx->codec_id == s->parser->codec_ids[1] ||
128 avctx->codec_id == s->parser->codec_ids[2] ||
129 avctx->codec_id == s->parser->codec_ids[3] ||
130 avctx->codec_id == s->parser->codec_ids[4]);
132 if (!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
133 s->next_frame_offset =
135 s->flags |= PARSER_FLAG_FETCHED_OFFSET;
139 /* padding is always necessary even if EOF, so we add it here */
140 memset(dummy_buf, 0, sizeof(dummy_buf));
142 } else if (s->cur_offset + buf_size != s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
143 /* add a new packet descriptor */
144 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
145 s->cur_frame_start_index = i;
146 s->cur_frame_offset[i] = s->cur_offset;
147 s->cur_frame_end[i] = s->cur_offset + buf_size;
148 s->cur_frame_pts[i] = pts;
149 s->cur_frame_dts[i] = dts;
150 s->cur_frame_pos[i] = pos;
153 if (s->fetch_timestamp) {
154 s->fetch_timestamp = 0;
155 s->last_pts = s->pts;
156 s->last_dts = s->dts;
157 s->last_pos = s->pos;
158 ff_fetch_timestamp(s, 0, 0, 0);
160 /* WARNING: the returned index can be negative */
161 index = s->parser->parser_parse(s, avctx, (const uint8_t **) poutbuf,
162 poutbuf_size, buf, buf_size);
163 av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
164 #define FILL(name) if(s->name > 0 && avctx->name <= 0) avctx->name = s->name
165 if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
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;
178 /* Don't return a pointer to dummy_buf. */
183 s->cur_offset += index;
187 #if FF_API_PARSER_CHANGE
188 int av_parser_change(AVCodecParserContext *s, AVCodecContext *avctx,
189 uint8_t **poutbuf, int *poutbuf_size,
190 const uint8_t *buf, int buf_size, int keyframe)
192 if (s && s->parser->split) {
193 if (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER ||
194 avctx->flags2 & AV_CODEC_FLAG2_LOCAL_HEADER) {
195 int i = s->parser->split(avctx, buf, buf_size);
201 /* cast to avoid warning about discarding qualifiers */
202 *poutbuf = (uint8_t *) buf;
203 *poutbuf_size = buf_size;
204 if (avctx->extradata) {
205 if (keyframe && (avctx->flags2 & AV_CODEC_FLAG2_LOCAL_HEADER)) {
206 int size = buf_size + avctx->extradata_size;
208 *poutbuf_size = size;
209 *poutbuf = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
211 return AVERROR(ENOMEM);
213 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
214 memcpy(*poutbuf + avctx->extradata_size, buf,
215 buf_size + AV_INPUT_BUFFER_PADDING_SIZE);
223 void av_parser_close(AVCodecParserContext *s)
226 if (s->parser->parser_close)
227 s->parser->parser_close(s);
228 av_freep(&s->priv_data);
233 int ff_combine_frame(ParseContext *pc, int next,
234 const uint8_t **buf, int *buf_size)
237 ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
238 pc->overread, pc->state, next, pc->index, pc->overread_index);
239 ff_dlog(NULL, "%X %X %X %X\n",
240 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
243 /* Copy overread bytes from last frame into buffer. */
244 for (; pc->overread > 0; pc->overread--)
245 pc->buffer[pc->index++] = pc->buffer[pc->overread_index++];
247 if (next > *buf_size)
248 return AVERROR(EINVAL);
250 /* flush remaining if EOF */
251 if (!*buf_size && next == END_NOT_FOUND)
254 pc->last_index = pc->index;
256 /* copy into buffer end return */
257 if (next == END_NOT_FOUND) {
258 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
259 *buf_size + pc->index +
260 AV_INPUT_BUFFER_PADDING_SIZE);
263 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", *buf_size + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
265 return AVERROR(ENOMEM);
267 pc->buffer = new_buffer;
268 memcpy(&pc->buffer[pc->index], *buf, *buf_size);
269 pc->index += *buf_size;
273 av_assert0(next >= 0 || pc->buffer);
276 pc->overread_index = pc->index + next;
278 /* append to buffer */
280 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
282 AV_INPUT_BUFFER_PADDING_SIZE);
284 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", next + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
287 return AVERROR(ENOMEM);
289 pc->buffer = new_buffer;
290 if (next > -AV_INPUT_BUFFER_PADDING_SIZE)
291 memcpy(&pc->buffer[pc->index], *buf,
292 next + AV_INPUT_BUFFER_PADDING_SIZE);
298 pc->overread += -8 - next;
301 /* store overread bytes */
302 for (; next < 0; next++) {
303 pc->state = pc->state << 8 | pc->buffer[pc->last_index + next];
304 pc->state64 = pc->state64 << 8 | pc->buffer[pc->last_index + next];
309 ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
310 pc->overread, pc->state, next, pc->index, pc->overread_index);
311 ff_dlog(NULL, "%X %X %X %X\n",
312 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
318 void ff_parse_close(AVCodecParserContext *s)
320 ParseContext *pc = s->priv_data;
322 av_freep(&pc->buffer);
325 int ff_mpeg4video_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
328 const uint8_t *ptr = buf, *end = buf + buf_size;
331 ptr = avpriv_find_start_code(ptr, end, &state);
332 if (state == 0x1B3 || state == 0x1B6)
333 return ptr - 4 - buf;