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88 lines
2.9 KiB
88 lines
2.9 KiB
/* |
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* Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com> |
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* |
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* This file is part of Libav. |
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* |
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* Libav 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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* Libav 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 Libav; 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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#ifndef AVRESAMPLE_DITHER_H |
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#define AVRESAMPLE_DITHER_H |
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#include "avresample.h" |
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#include "audio_data.h" |
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typedef struct DitherContext DitherContext; |
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typedef struct DitherDSPContext { |
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/** |
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* Convert samples from flt to s16 with added dither noise. |
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* |
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* @param dst destination float array, range -0.5 to 0.5 |
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* @param src source int array, range INT_MIN to INT_MAX. |
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* @param dither float dither noise array |
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* @param len number of samples |
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*/ |
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void (*quantize)(int16_t *dst, const float *src, float *dither, int len); |
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int ptr_align; ///< src and dst constraits for quantize() |
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int samples_align; ///< len constraits for quantize() |
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/** |
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* Convert dither noise from int to float with triangular distribution. |
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* |
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* @param dst destination float array, range -0.5 to 0.5 |
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* constraints: 32-byte aligned |
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* @param src0 source int array, range INT_MIN to INT_MAX. |
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* the array size is len * 2 |
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* constraints: 32-byte aligned |
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* @param len number of output noise samples |
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* constraints: multiple of 16 |
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*/ |
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void (*dither_int_to_float)(float *dst, int *src0, int len); |
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} DitherDSPContext; |
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/** |
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* Allocate and initialize a DitherContext. |
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* |
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* The parameters in the AVAudioResampleContext are used to initialize the |
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* DitherContext. |
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* |
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* @param avr AVAudioResampleContext |
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* @return newly-allocated DitherContext |
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*/ |
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DitherContext *ff_dither_alloc(AVAudioResampleContext *avr, |
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enum AVSampleFormat out_fmt, |
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enum AVSampleFormat in_fmt, |
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int channels, int sample_rate); |
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/** |
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* Free a DitherContext. |
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* |
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* @param c DitherContext |
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*/ |
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void ff_dither_free(DitherContext **c); |
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/** |
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* Convert audio sample format with dithering. |
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* |
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* @param c DitherContext |
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* @param dst destination audio data |
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* @param src source audio data |
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* @return 0 if ok, negative AVERROR code on failure |
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*/ |
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int ff_convert_dither(DitherContext *c, AudioData *dst, AudioData *src); |
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#endif /* AVRESAMPLE_DITHER_H */
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