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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 6148 | serge | 1 | /* |
| 2 | * copyright (c) 2006 Michael Niedermayer |
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| 3 | * |
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| 4 | * This file is part of FFmpeg. |
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| 5 | * |
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| 6 | * FFmpeg is free software; you can redistribute it and/or |
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| 7 | * modify it under the terms of the GNU Lesser General Public |
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| 8 | * License as published by the Free Software Foundation; either |
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| 9 | * version 2.1 of the License, or (at your option) any later version. |
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| 10 | * |
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| 11 | * FFmpeg is distributed in the hope that it will be useful, |
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| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 14 | * Lesser General Public License for more details. |
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| 15 | * |
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| 16 | * You should have received a copy of the GNU Lesser General Public |
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| 17 | * License along with FFmpeg; if not, write to the Free Software |
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| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 19 | */ |
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| 20 | |||
| 21 | #include "libavutil/common.h" |
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| 22 | #include "libavutil/intreadwrite.h" |
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| 23 | #include "avcodec.h" |
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| 24 | #include "mpegaudiodecheader.h" |
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| 25 | #include "mpegaudiodata.h" |
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| 26 | |||
| 27 | |||
| 28 | static int mp3_header_decompress(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args, |
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| 29 | uint8_t **poutbuf, int *poutbuf_size, |
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| 30 | const uint8_t *buf, int buf_size, int keyframe){ |
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| 31 | uint32_t header; |
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| 32 | int sample_rate= avctx->sample_rate; |
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| 33 | int sample_rate_index=0; |
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| 34 | int lsf, mpeg25, bitrate_index, frame_size; |
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| 35 | |||
| 36 | header = AV_RB32(buf); |
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| 37 | if(ff_mpa_check_header(header) >= 0){ |
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| 38 | *poutbuf= (uint8_t *) buf; |
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| 39 | *poutbuf_size= buf_size; |
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| 40 | |||
| 41 | return 0; |
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| 42 | } |
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| 43 | |||
| 44 | if(avctx->extradata_size != 15 || strcmp(avctx->extradata, "FFCMP3 0.0")){ |
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| 45 | av_log(avctx, AV_LOG_ERROR, "Extradata invalid %d\n", avctx->extradata_size); |
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| 46 | return -1; |
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| 47 | } |
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| 48 | |||
| 49 | header= AV_RB32(avctx->extradata+11) & MP3_MASK; |
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| 50 | |||
| 51 | lsf = sample_rate < (24000+32000)/2; |
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| 52 | mpeg25 = sample_rate < (12000+16000)/2; |
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| 53 | sample_rate_index= (header>>10)&3; |
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| 54 | sample_rate= avpriv_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25); //in case sample rate is a little off |
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| 55 | |||
| 56 | for(bitrate_index=2; bitrate_index<30; bitrate_index++){ |
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| 57 | frame_size = avpriv_mpa_bitrate_tab[lsf][2][bitrate_index>>1]; |
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| 58 | frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1); |
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| 59 | if(frame_size == buf_size + 4) |
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| 60 | break; |
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| 61 | if(frame_size == buf_size + 6) |
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| 62 | break; |
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| 63 | } |
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| 64 | if(bitrate_index == 30){ |
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| 65 | av_log(avctx, AV_LOG_ERROR, "Could not find bitrate_index.\n"); |
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| 66 | return -1; |
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| 67 | } |
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| 68 | |||
| 69 | header |= (bitrate_index&1)<<9; |
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| 70 | header |= (bitrate_index>>1)<<12; |
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| 71 | header |= (frame_size == buf_size + 4)<<16; //FIXME actually set a correct crc instead of 0 |
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| 72 | |||
| 73 | *poutbuf_size= frame_size; |
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| 74 | *poutbuf= av_malloc(frame_size + FF_INPUT_BUFFER_PADDING_SIZE); |
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| 75 | memcpy(*poutbuf + frame_size - buf_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); |
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| 76 | |||
| 77 | if(avctx->channels==2){ |
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| 78 | uint8_t *p= *poutbuf + frame_size - buf_size; |
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| 79 | if(lsf){ |
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| 80 | FFSWAP(int, p[1], p[2]); |
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| 81 | header |= (p[1] & 0xC0)>>2; |
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| 82 | p[1] &= 0x3F; |
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| 83 | }else{ |
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| 84 | header |= p[1] & 0x30; |
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| 85 | p[1] &= 0xCF; |
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| 86 | } |
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| 87 | } |
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| 88 | |||
| 89 | AV_WB32(*poutbuf, header); |
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| 90 | |||
| 91 | return 1; |
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| 92 | } |
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| 93 | |||
| 94 | AVBitStreamFilter ff_mp3_header_decompress_bsf={ |
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| 95 | .name = "mp3decomp", |
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| 96 | .filter = mp3_header_decompress, |
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| 97 | }; |