89 lines
2.9 KiB
C
89 lines
2.9 KiB
C
/*
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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, int apply_map);
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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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