2 * Common AAC and AC3 parser
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
24 #include "aac_ac3_parser.h"
26 int ff_aac_ac3_parse(AVCodecParserContext *s1,
27 AVCodecContext *avctx,
28 const uint8_t **poutbuf, int *poutbuf_size,
29 const uint8_t *buf, int buf_size)
31 AACAC3ParseContext *s = s1->priv_data;
32 ParseContext *pc = &s->pc;
37 if(s->remaining_size <= buf_size){
38 if(s->remaining_size){
40 s->remaining_size = 0;
41 }else{ //we need a header first
43 for(i=s->remaining_size; i<buf_size; i++){
44 s->state = (s->state<<8) + buf[i];
45 if((len=s->sync(s->state, s, &s->need_next_header, &new_frame_start)))
51 i-= s->header_size -1;
52 s->remaining_size = len + i;
57 if(ff_combine_frame(pc, i, &buf, &buf_size)<0){
58 s->remaining_size -= FFMIN(s->remaining_size, buf_size);
65 *poutbuf_size = buf_size;
67 /* update codec info */
68 avctx->sample_rate = s->sample_rate;
69 /* allow downmixing to stereo (or mono for AC3) */
70 if(avctx->request_channels > 0 &&
71 avctx->request_channels < s->channels &&
72 (avctx->request_channels <= 2 ||
73 (avctx->request_channels == 1 &&
74 avctx->codec_id == CODEC_ID_AC3))) {
75 avctx->channels = avctx->request_channels;
77 avctx->channels = s->channels;
79 avctx->bit_rate = s->bit_rate;
80 avctx->frame_size = s->samples;