Add new_frame_start and need_next_header.
[libav.git] / libavcodec / aac_ac3_parser.c
CommitLineData
99ff31dc
AJ
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,
99ff31dc
AJ
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;
454064ad
MN
32 ParseContext *pc = &s->pc;
33 int len, i;
133ac890 34 int new_frame_start;
99ff31dc 35
454064ad
MN
36 i=END_NOT_FOUND;
37 if(s->remaining_size <= buf_size){
38 if(s->remaining_size){
39 i= s->remaining_size;
40 s->remaining_size = 0;
41 }else{ //we need a header first
42 len=0;
43 for(i=s->remaining_size; i<buf_size; i++){
44 s->state = (s->state<<8) + buf[i];
133ac890 45 if((len=s->sync(s->state, s, &s->need_next_header, &new_frame_start)))
454064ad
MN
46 break;
47 }
48 if(len<=0){
49 i=END_NOT_FOUND;
50 }else{
51 i-= s->header_size -1;
52 s->remaining_size = len + i;
53 }
54 }
55 }
99ff31dc 56
454064ad
MN
57 if(ff_combine_frame(pc, i, &buf, &buf_size)<0){
58 s->remaining_size -= FFMIN(s->remaining_size, buf_size);
59 *poutbuf = NULL;
60 *poutbuf_size = 0;
61 return buf_size;
62 }
469d8816 63
454064ad
MN
64 *poutbuf = buf;
65 *poutbuf_size = buf_size;
211dd1e8 66
99ff31dc 67 /* update codec info */
c599e297 68 avctx->sample_rate = s->sample_rate;
ef7f2bb7 69 /* allow downmixing to stereo (or mono for AC3) */
f228eb73 70 if(avctx->request_channels > 0 &&
c599e297 71 avctx->request_channels < s->channels &&
ef7f2bb7
JR
72 (avctx->request_channels <= 2 ||
73 (avctx->request_channels == 1 &&
74 avctx->codec_id == CODEC_ID_AC3))) {
f228eb73 75 avctx->channels = avctx->request_channels;
6cd325c1 76 } else {
c599e297 77 avctx->channels = s->channels;
f228eb73 78 }
c599e297
JR
79 avctx->bit_rate = s->bit_rate;
80 avctx->frame_size = s->samples;
454064ad
MN
81
82 return i;
99ff31dc 83}