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/*
* Common AAC and AC3 parser
* Copyright (c) 2003 Fabrice Bellard.
* Copyright (c) 2003 Michael Niedermayer.
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "parser.h"
#include "aac_ac3_parser.h"
int ff_aac_ac3_parse(AVCodecParserContext *s1,
AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
AACAC3ParseContext *s = s1->priv_data;
const uint8_t *buf_ptr;
int len, sample_rate, bit_rate, channels, samples;
*poutbuf = NULL;
*poutbuf_size = 0;
buf_ptr = buf;
while (buf_size > 0) {
int size_needed= s->frame_size ? s->frame_size : s->header_size;
len = s->inbuf_ptr - s->inbuf;
if(len<size_needed){
len = FFMIN(size_needed - len, buf_size);
memcpy(s->inbuf_ptr, buf_ptr, len);
buf_ptr += len;
s->inbuf_ptr += len;
buf_size -= len;
}
if (s->frame_size == 0) {
if ((s->inbuf_ptr - s->inbuf) == s->header_size) {
len = s->sync(s->inbuf, &channels, &sample_rate, &bit_rate,
&samples);
if (len == 0) {
/* no sync found : move by one byte (inefficient, but simple!) */
memmove(s->inbuf, s->inbuf + 1, s->header_size - 1);
s->inbuf_ptr--;
} else {
s->frame_size = len;
/* update codec info */
avctx->sample_rate = sample_rate;
/* allow downmixing to mono or stereo for AC3 */
if(avctx->request_channels > 0 &&
avctx->request_channels < channels &&
avctx->request_channels <= 2 &&
avctx->codec_id == CODEC_ID_AC3) {
avctx->channels = avctx->request_channels;
} else {
avctx->channels = channels;
}
avctx->bit_rate = bit_rate;
avctx->frame_size = samples;
}
}
} else {
if(s->inbuf_ptr - s->inbuf == s->frame_size){
*poutbuf = s->inbuf;
*poutbuf_size = s->frame_size;
s->inbuf_ptr = s->inbuf;
s->frame_size = 0;
break;
}
}
}
return buf_ptr - buf;
}
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