1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-11-26 19:01:44 +02:00
FFmpeg/libavcodec/mpegaudio_parser.c
Michael Niedermayer dd8ffc1925 Merge remote-tracking branch 'qatar/master'
* qatar/master: (47 commits)
  lavc: hide private symbols.
  lavc: deprecate img_get_alpha_info().
  lavc: use avpriv_ prefix for ff_toupper4.
  lavc: use avpriv_ prefix for ff_copy_bits and align_put_bits.
  lavc: use avpriv_ prefix for ff_ac3_parse_header.
  lavc: use avpriv_ prefix for ff_frame_rate_tab.
  lavc: rename ff_find_start_code to avpriv_mpv_find_start_code
  lavc: use avpriv_ prefix for ff_split_xiph_headers.
  lavc: use avpriv_ prefix for ff_dirac_parse_sequence_header.
  lavc: use avpriv_ prefix for some dv symbols used in lavf.
  lavc: use avpriv_ prefix for some flac symbols used in lavf.
  lavc: use avpriv_ prefix for some mpeg4audio symbols used in lavf.
  lavc: use avpriv_ prefix for some mpegaudio symbols used in lavf.
  lavc: use avpriv_ prefix for ff_aac_parse_header().
  lavf: hide private symbols.
  lavf: use avpriv_ prefix for some dv functions.
  lavf: use avpriv_ prefix for ff_new_chapter().
  avcodec: add CODEC_CAP_DELAY note to avcodec_decode_audio3() documentation
  avcodec: clarify the CODEC_CAP_DELAY note in avcodec_decode_video2()
  avcodec: clarify documentation of CODEC_CAP_DELAY
  ...

Conflicts:
	configure
	doc/general.texi
	libavcodec/Makefile
	libavcodec/aacdec.c
	libavcodec/allcodecs.c
	libavcodec/avcodec.h
	libavcodec/dv.c
	libavcodec/dvdata.c
	libavcodec/dvdata.h
	libavcodec/libspeexenc.c
	libavcodec/mpegvideo.c
	libavcodec/version.h
	libavformat/avidec.c
	libavformat/dv.c
	libavformat/dv.h
	libavformat/flvenc.c
	libavformat/mov.c
	libavformat/mp3enc.c
	libavformat/oggparsespeex.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2011-10-21 02:01:26 +02:00

110 lines
3.2 KiB
C

/*
* MPEG Audio 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 "mpegaudiodecheader.h"
typedef struct MpegAudioParseContext {
ParseContext pc;
int frame_size;
uint32_t header;
int header_count;
} 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,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
MpegAudioParseContext *s = s1->priv_data;
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;
if(!s->frame_size){
next= i;
break;
}
}else{
while(i<buf_size){
int ret, sr, channels, bit_rate, frame_size;
state= (state<<8) + buf[i++];
ret = avpriv_mpa_decode_header(avctx, state, &sr, &channels, &frame_size, &bit_rate);
if (ret < 4) {
if(i > 4)
s->header_count= -2;
} else {
if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header)
s->header_count= -3;
s->header= state;
s->header_count++;
s->frame_size = ret-4;
if(s->header_count > 1){
avctx->sample_rate= sr;
avctx->channels = channels;
avctx->frame_size = frame_size;
avctx->bit_rate = bit_rate;
}
break;
}
}
}
}
pc->state= state;
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
AVCodecParser ff_mpegaudio_parser = {
{ CODEC_ID_MP1, CODEC_ID_MP2, CODEC_ID_MP3 },
sizeof(MpegAudioParseContext),
NULL,
mpegaudio_parse,
ff_parse_close,
};