mirror of https://git.ffmpeg.org/ffmpeg.git
89 lines
2.8 KiB
C
89 lines
2.8 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 "libavutil/common.h"
|
|
#include "libavutil/intreadwrite.h"
|
|
#include "avcodec.h"
|
|
#include "mpegaudiodecheader.h"
|
|
|
|
|
|
static int mp3_header_compress(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, extraheader;
|
|
int mode_extension, header_size;
|
|
|
|
if(avctx->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL){
|
|
av_log(avctx, AV_LOG_ERROR, "not standards compliant\n");
|
|
return -1;
|
|
}
|
|
|
|
header = AV_RB32(buf);
|
|
mode_extension= (header>>4)&3;
|
|
|
|
if(ff_mpa_check_header(header) < 0 || (header&0x60000) != 0x20000){
|
|
output_unchanged:
|
|
*poutbuf= (uint8_t *) buf;
|
|
*poutbuf_size= buf_size;
|
|
|
|
av_log(avctx, AV_LOG_INFO, "cannot compress %08X\n", header);
|
|
return 0;
|
|
}
|
|
|
|
if(avctx->extradata_size == 0){
|
|
avctx->extradata_size=15;
|
|
avctx->extradata= av_malloc(avctx->extradata_size);
|
|
strcpy(avctx->extradata, "FFCMP3 0.0");
|
|
memcpy(avctx->extradata+11, buf, 4);
|
|
}
|
|
if(avctx->extradata_size != 15){
|
|
av_log(avctx, AV_LOG_ERROR, "Extradata invalid\n");
|
|
return -1;
|
|
}
|
|
extraheader = AV_RB32(avctx->extradata+11);
|
|
if((extraheader&MP3_MASK) != (header&MP3_MASK))
|
|
goto output_unchanged;
|
|
|
|
header_size= (header&0x10000) ? 4 : 6;
|
|
|
|
*poutbuf_size= buf_size - header_size;
|
|
*poutbuf= av_malloc(buf_size - header_size + FF_INPUT_BUFFER_PADDING_SIZE);
|
|
memcpy(*poutbuf, buf + header_size, buf_size - header_size + FF_INPUT_BUFFER_PADDING_SIZE);
|
|
|
|
if(avctx->channels==2){
|
|
if((header & (3<<19)) != 3<<19){
|
|
(*poutbuf)[1] &= 0x3F;
|
|
(*poutbuf)[1] |= mode_extension<<6;
|
|
FFSWAP(int, (*poutbuf)[1], (*poutbuf)[2]);
|
|
}else{
|
|
(*poutbuf)[1] &= 0x8F;
|
|
(*poutbuf)[1] |= mode_extension<<4;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
AVBitStreamFilter ff_mp3_header_compress_bsf={
|
|
"mp3comp",
|
|
0,
|
|
mp3_header_compress,
|
|
};
|