Drop non key frames before the first key frame.
[libav.git] / libavcodec / aac_ac3_parser.c
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1/*
2 * Common AAC and AC3 parser
3 * Copyright (c) 2003 Fabrice Bellard.
4 * Copyright (c) 2003 Michael Niedermayer.
5 *
6 * This file is part of FFmpeg.
7 *
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.
12 *
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.
17 *
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
21 */
22
23#include "parser.h"
24#include "aac_ac3_parser.h"
25
679c2294 26int ff_aac_ac3_parse(AVCodecParserContext *s1,
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27 AVCodecContext *avctx,
28 const uint8_t **poutbuf, int *poutbuf_size,
29 const uint8_t *buf, int buf_size)
30{
679c2294 31 AACAC3ParseContext *s = s1->priv_data;
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32 const uint8_t *buf_ptr;
33 int len, sample_rate, bit_rate, channels, samples;
34
35 *poutbuf = NULL;
36 *poutbuf_size = 0;
37
38 buf_ptr = buf;
39 while (buf_size > 0) {
211dd1e8 40 int size_needed= s->frame_size ? s->frame_size : s->header_size;
99ff31dc 41 len = s->inbuf_ptr - s->inbuf;
99ff31dc 42
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43 if(len<size_needed){
44 len = FFMIN(size_needed - len, buf_size);
99ff31dc 45 memcpy(s->inbuf_ptr, buf_ptr, len);
211dd1e8 46 buf_ptr += len;
99ff31dc 47 s->inbuf_ptr += len;
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48 buf_size -= len;
49 }
50
51 if (s->frame_size == 0) {
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52 if ((s->inbuf_ptr - s->inbuf) == s->header_size) {
53 len = s->sync(s->inbuf, &channels, &sample_rate, &bit_rate,
54 &samples);
55 if (len == 0) {
56 /* no sync found : move by one byte (inefficient, but simple!) */
57 memmove(s->inbuf, s->inbuf + 1, s->header_size - 1);
58 s->inbuf_ptr--;
59 } else {
60 s->frame_size = len;
61 /* update codec info */
62 avctx->sample_rate = sample_rate;
5706c0be 63 avctx->channels = channels;
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64 avctx->bit_rate = bit_rate;
65 avctx->frame_size = samples;
66 }
67 }
68 } else {
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69 if(s->inbuf_ptr - s->inbuf == s->frame_size){
70 *poutbuf = s->inbuf;
71 *poutbuf_size = s->frame_size;
72 s->inbuf_ptr = s->inbuf;
73 s->frame_size = 0;
74 break;
75 }
76 }
77 }
78 return buf_ptr - buf;
79}