mirror of https://github.com/FFmpeg/FFmpeg.git
Originally committed as revision 9062 to svn://svn.ffmpeg.org/ffmpeg/trunkpull/126/head
Aurelien Jacobs
18 years ago
parent
677fe2e226
commit
b57eed12da
4 changed files with 102 additions and 81 deletions
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/*
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* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "avcodec.h" |
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#include "mpegaudio.h" |
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#include "mpegaudiodata.h" |
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static int mp3_header_decompress(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args, |
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uint8_t **poutbuf, int *poutbuf_size, |
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const uint8_t *buf, int buf_size, int keyframe){ |
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uint32_t header; |
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int sample_rate= avctx->sample_rate; |
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int sample_rate_index=0; |
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int lsf, mpeg25, bitrate_index, frame_size; |
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header = AV_RB32(buf); |
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if(ff_mpa_check_header(header) >= 0){ |
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*poutbuf= (uint8_t *) buf; |
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*poutbuf_size= buf_size; |
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return 0; |
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} |
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if(avctx->extradata_size != 15 || strcmp(avctx->extradata, "FFCMP3 0.0")){ |
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av_log(avctx, AV_LOG_ERROR, "Extradata invalid %d\n", avctx->extradata_size); |
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return -1; |
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} |
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header= AV_RB32(avctx->extradata+11) & MP3_MASK; |
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lsf = sample_rate < (24000+32000)/2; |
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mpeg25 = sample_rate < (12000+16000)/2; |
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sample_rate_index= (header>>10)&3; |
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sample_rate= ff_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25); //in case sample rate is a little off
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for(bitrate_index=2; bitrate_index<30; bitrate_index++){ |
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frame_size = ff_mpa_bitrate_tab[lsf][2][bitrate_index>>1]; |
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frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1); |
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if(frame_size == buf_size + 4) |
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break; |
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if(frame_size == buf_size + 6) |
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break; |
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} |
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if(bitrate_index == 30){ |
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av_log(avctx, AV_LOG_ERROR, "couldnt find bitrate_index\n"); |
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return -1; |
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} |
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header |= (bitrate_index&1)<<9; |
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header |= (bitrate_index>>1)<<12; |
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header |= (frame_size == buf_size + 4)<<16; //FIXME actually set a correct crc instead of 0
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*poutbuf_size= frame_size; |
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*poutbuf= av_malloc(frame_size + FF_INPUT_BUFFER_PADDING_SIZE); |
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memcpy(*poutbuf + frame_size - buf_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); |
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if(avctx->channels==2){ |
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uint8_t *p= *poutbuf + frame_size - buf_size; |
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if(lsf){ |
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FFSWAP(int, p[1], p[2]); |
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header |= (p[1] & 0xC0)>>2; |
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p[1] &= 0x3F; |
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}else{ |
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header |= p[1] & 0x30; |
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p[1] &= 0xCF; |
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} |
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} |
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(*poutbuf)[0]= header>>24; |
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(*poutbuf)[1]= header>>16; |
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(*poutbuf)[2]= header>> 8; |
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(*poutbuf)[3]= header ; |
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return 1; |
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} |
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AVBitStreamFilter mp3_header_decompress_bsf={ |
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"mp3decomp", |
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0, |
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mp3_header_decompress, |
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}; |
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