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- /*
- * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
- #ifndef AVRESAMPLE_DITHER_H
- #define AVRESAMPLE_DITHER_H
-
- #include "avresample.h"
- #include "audio_data.h"
-
- typedef struct DitherContext DitherContext;
-
- typedef struct DitherDSPContext {
- /**
- * Convert samples from flt to s16 with added dither noise.
- *
- * @param dst destination float array, range -0.5 to 0.5
- * @param src source int array, range INT_MIN to INT_MAX.
- * @param dither float dither noise array
- * @param len number of samples
- */
- void (*quantize)(int16_t *dst, const float *src, float *dither, int len);
-
- int ptr_align; ///< src and dst constraints for quantize()
- int samples_align; ///< len constraints for quantize()
-
- /**
- * Convert dither noise from int to float with triangular distribution.
- *
- * @param dst destination float array, range -0.5 to 0.5
- * constraints: 32-byte aligned
- * @param src0 source int array, range INT_MIN to INT_MAX.
- * the array size is len * 2
- * constraints: 32-byte aligned
- * @param len number of output noise samples
- * constraints: multiple of 16
- */
- void (*dither_int_to_float)(float *dst, int *src0, int len);
- } DitherDSPContext;
-
- /**
- * Allocate and initialize a DitherContext.
- *
- * The parameters in the AVAudioResampleContext are used to initialize the
- * DitherContext.
- *
- * @param avr AVAudioResampleContext
- * @return newly-allocated DitherContext
- */
- DitherContext *ff_dither_alloc(AVAudioResampleContext *avr,
- enum AVSampleFormat out_fmt,
- enum AVSampleFormat in_fmt,
- int channels, int sample_rate, int apply_map);
-
- /**
- * Free a DitherContext.
- *
- * @param c DitherContext
- */
- void ff_dither_free(DitherContext **c);
-
- /**
- * Convert audio sample format with dithering.
- *
- * @param c DitherContext
- * @param dst destination audio data
- * @param src source audio data
- * @return 0 if ok, negative AVERROR code on failure
- */
- int ff_convert_dither(DitherContext *c, AudioData *dst, AudioData *src);
-
- /* arch-specific initialization functions */
-
- void ff_dither_init_x86(DitherDSPContext *ddsp,
- enum AVResampleDitherMethod method);
-
- #endif /* AVRESAMPLE_DITHER_H */
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