mirror of
https://github.com/xenia-project/FFmpeg.git
synced 2024-11-24 12:09:55 +00:00
97 lines
3.1 KiB
C
97 lines
3.1 KiB
C
/*
|
|
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* This file is part of Libav.
|
|
*
|
|
* Libav 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.
|
|
*
|
|
* Libav 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 Libav; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "avcodec.h"
|
|
#include "mpegaudio.h"
|
|
#include "mpegaudiodata.h"
|
|
|
|
|
|
static int mp3_header_decompress(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args,
|
|
uint8_t **poutbuf, int *poutbuf_size,
|
|
const uint8_t *buf, int buf_size, int keyframe){
|
|
uint32_t header;
|
|
int sample_rate= avctx->sample_rate;
|
|
int sample_rate_index=0;
|
|
int lsf, mpeg25, bitrate_index, frame_size;
|
|
|
|
header = AV_RB32(buf);
|
|
if(ff_mpa_check_header(header) >= 0){
|
|
*poutbuf= (uint8_t *) buf;
|
|
*poutbuf_size= buf_size;
|
|
|
|
return 0;
|
|
}
|
|
|
|
if(avctx->extradata_size != 15 || strcmp(avctx->extradata, "FFCMP3 0.0")){
|
|
av_log(avctx, AV_LOG_ERROR, "Extradata invalid %d\n", avctx->extradata_size);
|
|
return -1;
|
|
}
|
|
|
|
header= AV_RB32(avctx->extradata+11) & MP3_MASK;
|
|
|
|
lsf = sample_rate < (24000+32000)/2;
|
|
mpeg25 = sample_rate < (12000+16000)/2;
|
|
sample_rate_index= (header>>10)&3;
|
|
sample_rate= ff_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25); //in case sample rate is a little off
|
|
|
|
for(bitrate_index=2; bitrate_index<30; bitrate_index++){
|
|
frame_size = ff_mpa_bitrate_tab[lsf][2][bitrate_index>>1];
|
|
frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1);
|
|
if(frame_size == buf_size + 4)
|
|
break;
|
|
if(frame_size == buf_size + 6)
|
|
break;
|
|
}
|
|
if(bitrate_index == 30){
|
|
av_log(avctx, AV_LOG_ERROR, "Could not find bitrate_index.\n");
|
|
return -1;
|
|
}
|
|
|
|
header |= (bitrate_index&1)<<9;
|
|
header |= (bitrate_index>>1)<<12;
|
|
header |= (frame_size == buf_size + 4)<<16; //FIXME actually set a correct crc instead of 0
|
|
|
|
*poutbuf_size= frame_size;
|
|
*poutbuf= av_malloc(frame_size + FF_INPUT_BUFFER_PADDING_SIZE);
|
|
memcpy(*poutbuf + frame_size - buf_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
|
|
|
|
if(avctx->channels==2){
|
|
uint8_t *p= *poutbuf + frame_size - buf_size;
|
|
if(lsf){
|
|
FFSWAP(int, p[1], p[2]);
|
|
header |= (p[1] & 0xC0)>>2;
|
|
p[1] &= 0x3F;
|
|
}else{
|
|
header |= p[1] & 0x30;
|
|
p[1] &= 0xCF;
|
|
}
|
|
}
|
|
|
|
AV_WB32(*poutbuf, header);
|
|
|
|
return 1;
|
|
}
|
|
|
|
AVBitStreamFilter ff_mp3_header_decompress_bsf={
|
|
"mp3decomp",
|
|
0,
|
|
mp3_header_decompress,
|
|
};
|