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| Rev | Author | Line No. | Line |
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| 6148 | serge | 1 | /* |
| 2 | * Copyright (c) 2012 Justin Ruggles |
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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 | #ifndef AVRESAMPLE_DITHER_H |
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| 22 | #define AVRESAMPLE_DITHER_H |
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| 23 | |||
| 24 | #include "avresample.h" |
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| 25 | #include "audio_data.h" |
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| 26 | |||
| 27 | typedef struct DitherContext DitherContext; |
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| 28 | |||
| 29 | typedef struct DitherDSPContext { |
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| 30 | /** |
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| 31 | * Convert samples from flt to s16 with added dither noise. |
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| 32 | * |
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| 33 | * @param dst destination float array, range -0.5 to 0.5 |
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| 34 | * @param src source int array, range INT_MIN to INT_MAX. |
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| 35 | * @param dither float dither noise array |
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| 36 | * @param len number of samples |
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| 37 | */ |
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| 38 | void (*quantize)(int16_t *dst, const float *src, float *dither, int len); |
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| 39 | |||
| 40 | int ptr_align; ///< src and dst constraits for quantize() |
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| 41 | int samples_align; ///< len constraits for quantize() |
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| 42 | |||
| 43 | /** |
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| 44 | * Convert dither noise from int to float with triangular distribution. |
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| 45 | * |
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| 46 | * @param dst destination float array, range -0.5 to 0.5 |
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| 47 | * constraints: 32-byte aligned |
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| 48 | * @param src0 source int array, range INT_MIN to INT_MAX. |
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| 49 | * the array size is len * 2 |
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| 50 | * constraints: 32-byte aligned |
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| 51 | * @param len number of output noise samples |
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| 52 | * constraints: multiple of 16 |
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| 53 | */ |
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| 54 | void (*dither_int_to_float)(float *dst, int *src0, int len); |
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| 55 | } DitherDSPContext; |
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| 56 | |||
| 57 | /** |
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| 58 | * Allocate and initialize a DitherContext. |
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| 59 | * |
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| 60 | * The parameters in the AVAudioResampleContext are used to initialize the |
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| 61 | * DitherContext. |
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| 62 | * |
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| 63 | * @param avr AVAudioResampleContext |
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| 64 | * @return newly-allocated DitherContext |
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| 65 | */ |
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| 66 | DitherContext *ff_dither_alloc(AVAudioResampleContext *avr, |
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| 67 | enum AVSampleFormat out_fmt, |
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| 68 | enum AVSampleFormat in_fmt, |
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| 69 | int channels, int sample_rate, int apply_map); |
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| 70 | |||
| 71 | /** |
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| 72 | * Free a DitherContext. |
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| 73 | * |
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| 74 | * @param c DitherContext |
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| 75 | */ |
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| 76 | void ff_dither_free(DitherContext **c); |
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| 77 | |||
| 78 | /** |
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| 79 | * Convert audio sample format with dithering. |
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| 80 | * |
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| 81 | * @param c DitherContext |
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| 82 | * @param dst destination audio data |
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| 83 | * @param src source audio data |
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| 84 | * @return 0 if ok, negative AVERROR code on failure |
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| 85 | */ |
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| 86 | int ff_convert_dither(DitherContext *c, AudioData *dst, AudioData *src); |
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| 87 | |||
| 88 | /* arch-specific initialization functions */ |
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| 89 | |||
| 90 | void ff_dither_init_x86(DitherDSPContext *ddsp, |
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| 91 | enum AVResampleDitherMethod method); |
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| 92 | |||
| 93 | #endif /* AVRESAMPLE_DITHER_H */ |