repositories / deb_ffmpeg.git / blame
| Commit | Line | Data |
|---|---|---|
| 2ba45a60 DM |
1 | /* |
| 2 | * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> | |
| 3 | * | |
| 4 | * This file is part of FFmpeg. | |
| 5 | * | |
| 6 | * FFmpeg is free software; you can redistribute it and/or | |
| 7 | * modify it under the terms of the GNU Lesser General Public | |
| 8 | * License as published by the Free Software Foundation; either | |
| 9 | * version 2.1 of the License, or (at your option) any later version. | |
| 10 | * | |
| 11 | * FFmpeg is distributed in the hope that it will be useful, | |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 14 | * Lesser General Public License for more details. | |
| 15 | * | |
| 16 | * You should have received a copy of the GNU Lesser General Public | |
| 17 | * License along with FFmpeg; if not, write to the Free Software | |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| 19 | */ | |
| 20 | ||
| 21 | #include "libavutil/common.h" | |
| 22 | #include "libavutil/intreadwrite.h" | |
| 23 | #include "avcodec.h" | |
| 24 | #include "mpegaudiodecheader.h" | |
| 25 | #include "mpegaudiodata.h" | |
| 26 | ||
| 27 | ||
| 28 | static int mp3_header_decompress(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args, | |
| 29 | uint8_t **poutbuf, int *poutbuf_size, | |
| 30 | const uint8_t *buf, int buf_size, int keyframe){ | |
| 31 | uint32_t header; | |
| 32 | int sample_rate= avctx->sample_rate; | |
| 33 | int sample_rate_index=0; | |
| 34 | int lsf, mpeg25, bitrate_index, frame_size; | |
| 35 | ||
| 36 | header = AV_RB32(buf); | |
| 37 | if(ff_mpa_check_header(header) >= 0){ | |
| 38 | *poutbuf= (uint8_t *) buf; | |
| 39 | *poutbuf_size= buf_size; | |
| 40 | ||
| 41 | return 0; | |
| 42 | } | |
| 43 | ||
| 44 | if(avctx->extradata_size != 15 || strcmp(avctx->extradata, "FFCMP3 0.0")){ | |
| 45 | av_log(avctx, AV_LOG_ERROR, "Extradata invalid %d\n", avctx->extradata_size); | |
| 46 | return -1; | |
| 47 | } | |
| 48 | ||
| 49 | header= AV_RB32(avctx->extradata+11) & MP3_MASK; | |
| 50 | ||
| 51 | lsf = sample_rate < (24000+32000)/2; | |
| 52 | mpeg25 = sample_rate < (12000+16000)/2; | |
| 53 | sample_rate_index= (header>>10)&3; | |
| 54 | sample_rate= avpriv_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25); //in case sample rate is a little off | |
| 55 | ||
| 56 | for(bitrate_index=2; bitrate_index<30; bitrate_index++){ | |
| 57 | frame_size = avpriv_mpa_bitrate_tab[lsf][2][bitrate_index>>1]; | |
| 58 | frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1); | |
| 59 | if(frame_size == buf_size + 4) | |
| 60 | break; | |
| 61 | if(frame_size == buf_size + 6) | |
| 62 | break; | |
| 63 | } | |
| 64 | if(bitrate_index == 30){ | |
| 65 | av_log(avctx, AV_LOG_ERROR, "Could not find bitrate_index.\n"); | |
| 66 | return -1; | |
| 67 | } | |
| 68 | ||
| 69 | header |= (bitrate_index&1)<<9; | |
| 70 | header |= (bitrate_index>>1)<<12; | |
| 71 | header |= (frame_size == buf_size + 4)<<16; //FIXME actually set a correct crc instead of 0 | |
| 72 | ||
| 73 | *poutbuf_size= frame_size; | |
| 74 | *poutbuf= av_malloc(frame_size + FF_INPUT_BUFFER_PADDING_SIZE); | |
| 75 | memcpy(*poutbuf + frame_size - buf_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); | |
| 76 | ||
| 77 | if(avctx->channels==2){ | |
| 78 | uint8_t *p= *poutbuf + frame_size - buf_size; | |
| 79 | if(lsf){ | |
| 80 | FFSWAP(int, p[1], p[2]); | |
| 81 | header |= (p[1] & 0xC0)>>2; | |
| 82 | p[1] &= 0x3F; | |
| 83 | }else{ | |
| 84 | header |= p[1] & 0x30; | |
| 85 | p[1] &= 0xCF; | |
| 86 | } | |
| 87 | } | |
| 88 | ||
| 89 | AV_WB32(*poutbuf, header); | |
| 90 | ||
| 91 | return 1; | |
| 92 | } | |
| 93 | ||
| 94 | AVBitStreamFilter ff_mp3_header_decompress_bsf={ | |
| 95 | .name = "mp3decomp", | |
| 96 | .filter = mp3_header_decompress, | |
| 97 | }; |