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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 6148 | serge | 1 | /* |
| 2 | * ADX ADPCM codecs |
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| 3 | * Copyright (c) 2001,2003 BERO |
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| 4 | * |
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| 5 | * This file is part of FFmpeg. |
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| 6 | * |
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| 7 | * FFmpeg is free software; you can redistribute it and/or |
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| 8 | * modify it under the terms of the GNU Lesser General Public |
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| 9 | * License as published by the Free Software Foundation; either |
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| 10 | * version 2.1 of the License, or (at your option) any later version. |
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| 11 | * |
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| 12 | * FFmpeg is distributed in the hope that it will be useful, |
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| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 15 | * Lesser General Public License for more details. |
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| 16 | * |
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| 17 | * You should have received a copy of the GNU Lesser General Public |
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| 18 | * License along with FFmpeg; if not, write to the Free Software |
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| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 20 | */ |
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| 21 | |||
| 22 | /** |
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| 23 | * @file |
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| 24 | * SEGA CRI adx codecs. |
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| 25 | * |
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| 26 | * Reference documents: |
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| 27 | * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html |
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| 28 | * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/ |
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| 29 | */ |
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| 30 | |||
| 31 | #ifndef AVCODEC_ADX_H |
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| 32 | #define AVCODEC_ADX_H |
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| 33 | |||
| 34 | #include |
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| 35 | |||
| 36 | #include "avcodec.h" |
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| 37 | |||
| 38 | typedef struct ADXChannelState { |
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| 39 | int s1,s2; |
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| 40 | } ADXChannelState; |
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| 41 | |||
| 42 | typedef struct ADXContext { |
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| 43 | int channels; |
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| 44 | ADXChannelState prev[2]; |
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| 45 | int header_parsed; |
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| 46 | int eof; |
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| 47 | int cutoff; |
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| 48 | int coeff[2]; |
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| 49 | } ADXContext; |
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| 50 | |||
| 51 | #define COEFF_BITS 12 |
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| 52 | |||
| 53 | #define BLOCK_SIZE 18 |
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| 54 | #define BLOCK_SAMPLES 32 |
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| 55 | |||
| 56 | /** |
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| 57 | * Calculate LPC coefficients based on cutoff frequency and sample rate. |
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| 58 | * |
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| 59 | * @param cutoff cutoff frequency |
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| 60 | * @param sample_rate sample rate |
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| 61 | * @param bits number of bits used to quantize coefficients |
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| 62 | * @param[out] coeff 2 quantized LPC coefficients |
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| 63 | */ |
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| 64 | void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff); |
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| 65 | |||
| 66 | /** |
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| 67 | * Decode ADX stream header. |
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| 68 | * Sets avctx->channels and avctx->sample_rate. |
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| 69 | * |
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| 70 | * @param avctx codec context |
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| 71 | * @param buf header data |
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| 72 | * @param bufsize data size, should be at least 24 bytes |
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| 73 | * @param[out] header_size size of ADX header |
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| 74 | * @param[out] coeff 2 LPC coefficients, can be NULL |
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| 75 | * @return data offset or negative error code if header is invalid |
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| 76 | */ |
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| 77 | int avpriv_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf, |
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| 78 | int bufsize, int *header_size, int *coeff); |
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| 79 | |||
| 80 | #endif /* AVCODEC_ADX_H */ |