0cb41728 |
/*
* MPEG Audio parser |
406792e7 |
* Copyright (c) 2003 Fabrice Bellard
* Copyright (c) 2003 Michael Niedermayer |
0cb41728 |
*
* 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" |
4bd8e17c |
#include "mpegaudiodecheader.h" |
1d9c2dc8 |
#include "libavutil/common.h" |
0cb41728 |
typedef struct MpegAudioParseContext { |
2073fc84 |
ParseContext pc; |
0cb41728 |
int frame_size;
uint32_t header;
int header_count; |
29d8cd26 |
int no_bitrate; |
0cb41728 |
} MpegAudioParseContext;
#define MPA_HEADER_SIZE 4
/* header + layer + bitrate + freq + lsf/mpeg25 */
#define SAME_HEADER_MASK \
(0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19))
static int mpegaudio_parse(AVCodecParserContext *s1,
AVCodecContext *avctx, |
c53d2d90 |
const uint8_t **poutbuf, int *poutbuf_size, |
0cb41728 |
const uint8_t *buf, int buf_size)
{
MpegAudioParseContext *s = s1->priv_data; |
2073fc84 |
ParseContext *pc = &s->pc;
uint32_t state= pc->state;
int i;
int next= END_NOT_FOUND;
for(i=0; i<buf_size; ){
if(s->frame_size){
int inc= FFMIN(buf_size - i, s->frame_size);
i += inc;
s->frame_size -= inc; |
93b240f4 |
state = 0; |
2073fc84 |
if(!s->frame_size){
next= i;
break; |
0cb41728 |
} |
2073fc84 |
}else{
while(i<buf_size){
int ret, sr, channels, bit_rate, frame_size; |
5669ae84 |
enum AVCodecID codec_id; |
2073fc84 |
state= (state<<8) + buf[i++]; |
0cb41728 |
|
5669ae84 |
ret = avpriv_mpa_decode_header2(state, &sr, &channels, &frame_size, &bit_rate, &codec_id); |
2073fc84 |
if (ret < 4) { |
6776a8f1 |
if (i > 4)
s->header_count = -2; |
0cb41728 |
} else { |
2073fc84 |
if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header) |
0cb41728 |
s->header_count= -3; |
2073fc84 |
s->header= state; |
d30ee5ef |
s->header_count++; |
2073fc84 |
s->frame_size = ret-4; |
0cb41728 |
|
c33351f3 |
if (s->header_count > 0 + (avctx->codec_id != AV_CODEC_ID_NONE && avctx->codec_id != codec_id)) { |
d8e76049 |
avctx->sample_rate= sr; |
c96bd212 |
avctx->channels = channels; |
7575ffac |
s1->duration = frame_size; |
5669ae84 |
avctx->codec_id = codec_id; |
29d8cd26 |
if (s->no_bitrate || !avctx->bit_rate) {
s->no_bitrate = 1;
avctx->bit_rate += (bit_rate - avctx->bit_rate) / s->header_count;
} |
c96bd212 |
} |
2073fc84 |
break; |
5ffcb1be |
} |
0cb41728 |
}
} |
2073fc84 |
} |
0cb41728 |
|
2073fc84 |
pc->state= state;
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size; |
0cb41728 |
} |
2073fc84 |
*poutbuf = buf;
*poutbuf_size = buf_size;
return next; |
0cb41728 |
}
|
e7e2df27 |
AVCodecParser ff_mpegaudio_parser = { |
36ef5369 |
.codec_ids = { AV_CODEC_ID_MP1, AV_CODEC_ID_MP2, AV_CODEC_ID_MP3 }, |
5511ad14 |
.priv_data_size = sizeof(MpegAudioParseContext),
.parser_parse = mpegaudio_parse,
.parser_close = ff_parse_close, |
0cb41728 |
}; |