yading@11: /*
yading@11:  * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
yading@11:  *
yading@11:  * This file is part of Libav.
yading@11:  *
yading@11:  * Libav is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * Libav is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with Libav; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #ifndef AVRESAMPLE_DITHER_H
yading@11: #define AVRESAMPLE_DITHER_H
yading@11: 
yading@11: #include "avresample.h"
yading@11: #include "audio_data.h"
yading@11: 
yading@11: typedef struct DitherContext DitherContext;
yading@11: 
yading@11: typedef struct DitherDSPContext {
yading@11:     /**
yading@11:      * Convert samples from flt to s16 with added dither noise.
yading@11:      *
yading@11:      * @param dst    destination float array, range -0.5 to 0.5
yading@11:      * @param src    source int array, range INT_MIN to INT_MAX.
yading@11:      * @param dither float dither noise array
yading@11:      * @param len    number of samples
yading@11:      */
yading@11:     void (*quantize)(int16_t *dst, const float *src, float *dither, int len);
yading@11: 
yading@11:     int ptr_align;      ///< src and dst constraits for quantize()
yading@11:     int samples_align;  ///< len constraits for quantize()
yading@11: 
yading@11:     /**
yading@11:      * Convert dither noise from int to float with triangular distribution.
yading@11:      *
yading@11:      * @param dst  destination float array, range -0.5 to 0.5
yading@11:      *             constraints: 32-byte aligned
yading@11:      * @param src0 source int array, range INT_MIN to INT_MAX.
yading@11:      *             the array size is len * 2
yading@11:      *             constraints: 32-byte aligned
yading@11:      * @param len  number of output noise samples
yading@11:      *             constraints: multiple of 16
yading@11:      */
yading@11:     void (*dither_int_to_float)(float *dst, int *src0, int len);
yading@11: } DitherDSPContext;
yading@11: 
yading@11: /**
yading@11:  * Allocate and initialize a DitherContext.
yading@11:  *
yading@11:  * The parameters in the AVAudioResampleContext are used to initialize the
yading@11:  * DitherContext.
yading@11:  *
yading@11:  * @param avr  AVAudioResampleContext
yading@11:  * @return     newly-allocated DitherContext
yading@11:  */
yading@11: DitherContext *ff_dither_alloc(AVAudioResampleContext *avr,
yading@11:                                enum AVSampleFormat out_fmt,
yading@11:                                enum AVSampleFormat in_fmt,
yading@11:                                int channels, int sample_rate, int apply_map);
yading@11: 
yading@11: /**
yading@11:  * Free a DitherContext.
yading@11:  *
yading@11:  * @param c  DitherContext
yading@11:  */
yading@11: void ff_dither_free(DitherContext **c);
yading@11: 
yading@11: /**
yading@11:  * Convert audio sample format with dithering.
yading@11:  *
yading@11:  * @param c    DitherContext
yading@11:  * @param dst  destination audio data
yading@11:  * @param src  source audio data
yading@11:  * @return     0 if ok, negative AVERROR code on failure
yading@11:  */
yading@11: int ff_convert_dither(DitherContext *c, AudioData *dst, AudioData *src);
yading@11: 
yading@11: /* arch-specific initialization functions */
yading@11: 
yading@11: void ff_dither_init_x86(DitherDSPContext *ddsp,
yading@11:                         enum AVResampleDitherMethod method);
yading@11: 
yading@11: #endif /* AVRESAMPLE_DITHER_H */