swr: add dither support.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2012-04-10 19:52:42 +02:00
parent 5c1f312888
commit db2eadb2f5
6 changed files with 98 additions and 11 deletions

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@ -5,6 +5,6 @@ FFLIBS = avutil
HEADERS = swresample.h
OBJS = swresample.o audioconvert.o resample.o rematrix.o
OBJS = swresample.o audioconvert.o resample.o rematrix.o dither.o
TESTPROGS = swresample_test

56
libswresample/dither.c Normal file
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@ -0,0 +1,56 @@
/*
* Copyright (C) 2012 Michael Niedermayer (michaelni@gmx.at)
*
* This file is part of libswresample
*
* libswresample 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.
*
* libswresample 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 libswresample; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/avassert.h"
#include "swresample_internal.h"
void swri_get_dither(void *dst, int len, unsigned seed, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, enum SwrDitherType method) {
double scale = 0;
int i;
if(in_fmt == AV_SAMPLE_FMT_FLT || in_fmt == AV_SAMPLE_FMT_DBL){
if(out_fmt == AV_SAMPLE_FMT_S32) scale = 1.0/(1L<<31);
if(out_fmt == AV_SAMPLE_FMT_S16) scale = 1.0/(1L<<15);
if(out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1.0/(1L<< 7);
}
if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_S16) scale = 1L<<16;
if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<24;
if(in_fmt == AV_SAMPLE_FMT_S16 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<8;
for(i=0; i<len; i++){
double v;
seed = seed* 1664525 + 1013904223;
switch(method){
case SWR_DITHER_RECTANGULAR: v= ((double)seed) / UINT_MAX - 0.5; break;
default: av_assert0(0);
}
v*= scale;
switch(in_fmt){
case AV_SAMPLE_FMT_S16: ((int16_t*)dst)[i] = v; break;
case AV_SAMPLE_FMT_S32: ((int32_t*)dst)[i] = v; break;
case AV_SAMPLE_FMT_FLT: ((float *)dst)[i] = v; break;
case AV_SAMPLE_FMT_DBL: ((double *)dst)[i] = v; break;
default: av_assert0(0);
}
}
}

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@ -272,6 +272,14 @@ int swri_rematrix_init(SwrContext *s){
return 0;
}
void swri_sum2(enum AVSampleFormat format, void *dst, const void *src0, const void *src1, float coef0, float coef1, int len){
if(format == AV_SAMPLE_FMT_FLT){
sum2_float((float *)dst, (const float *)src0, (const float *)src1, coef0, coef1, len);
}else{
sum2_s16 ((int16_t*)dst, (const int16_t*)src0, (const int16_t*)src1, lrintf(coef0 * 32768), lrintf(coef1 * 32768), len);
}
}
int swri_rematrix(SwrContext *s, AudioData *out, AudioData *in, int len, int mustcopy){
int out_i, in_i, i, j;
@ -295,15 +303,8 @@ int swri_rematrix(SwrContext *s, AudioData *out, AudioData *in, int len, int mus
}
break;
case 2:
if(s->int_sample_fmt == AV_SAMPLE_FMT_FLT){
sum2_float((float *)out->ch[out_i], (const float *)in->ch[ s->matrix_ch[out_i][1] ], (const float *)in->ch[ s->matrix_ch[out_i][2] ],
s->matrix[out_i][ s->matrix_ch[out_i][1] ], s->matrix[out_i][ s->matrix_ch[out_i][2] ],
len);
}else{
sum2_s16 ((int16_t*)out->ch[out_i], (const int16_t*)in->ch[ s->matrix_ch[out_i][1] ], (const int16_t*)in->ch[ s->matrix_ch[out_i][2] ],
s->matrix32[out_i][ s->matrix_ch[out_i][1] ], s->matrix32[out_i][ s->matrix_ch[out_i][2] ],
len);
}
swri_sum2(s->int_sample_fmt, out->ch[out_i], in->ch[ s->matrix_ch[out_i][1] ], in->ch[ s->matrix_ch[out_i][2] ],
s->matrix[out_i][ s->matrix_ch[out_i][1] ], s->matrix[out_i][ s->matrix_ch[out_i][2] ], len);
break;
default:
if(s->int_sample_fmt == AV_SAMPLE_FMT_FLT){

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@ -53,6 +53,7 @@ static const AVOption options[]={
{"rmvol", "rematrix volume" , OFFSET(rematrix_volume), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, -1000, 1000, 0},
{"flags", NULL , OFFSET(flags) , AV_OPT_TYPE_FLAGS, {.dbl=0}, 0, UINT_MAX, 0, "flags"},
{"res", "force resampling", 0, AV_OPT_TYPE_CONST, {.dbl=SWR_FLAG_RESAMPLE}, INT_MIN, INT_MAX, 0, "flags"},
{"dither", "dither method" , OFFSET(dither_method), AV_OPT_TYPE_INT, {.dbl=0}, 0, SWR_DITHER_NB-1, 0},
{0}
};
@ -139,6 +140,7 @@ void swr_free(SwrContext **ss){
free_temp(&s->midbuf);
free_temp(&s->preout);
free_temp(&s->in_buffer);
free_temp(&s->dither);
swri_audio_convert_free(&s-> in_convert);
swri_audio_convert_free(&s->out_convert);
swri_audio_convert_free(&s->full_convert);
@ -156,6 +158,7 @@ int swr_init(struct SwrContext *s){
free_temp(&s->midbuf);
free_temp(&s->preout);
free_temp(&s->in_buffer);
free_temp(&s->dither);
swri_audio_convert_free(&s-> in_convert);
swri_audio_convert_free(&s->out_convert);
swri_audio_convert_free(&s->full_convert);
@ -281,6 +284,8 @@ av_assert0(s->out.ch_count);
s->in_buffer.planar = 1;
}
s->dither = s->preout;
if(s->rematrix)
return swri_rematrix_init(s);
@ -505,6 +510,21 @@ static int swr_convert_internal(struct SwrContext *s, AudioData *out, int out_co
}
if(preout != out && out_count){
if(s->dither_method){
int ch, i;
av_assert0(preout != in);
if((ret=realloc_audio(&s->dither, out_count))<0)
return ret;
if(ret)
for(ch=0; ch<s->dither.ch_count; ch++)
swri_get_dither(s->dither.ch[ch], s->dither.count, 12345678913579<<ch, s->out_sample_fmt, s->int_sample_fmt, s->dither_method);
av_assert0(s->dither.ch_count == preout->ch_count);
for(ch=0; ch<preout->ch_count; ch++){
swri_sum2(s->int_sample_fmt, preout->ch[ch], preout->ch[ch], s->dither.ch[ch], 1, 1, out_count);
}
}
//FIXME packed doesnt need more than 1 chan here!
swri_audio_convert(s->out_convert, out, preout, out_count);
}

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@ -30,7 +30,7 @@
#include "libavutil/samplefmt.h"
#define LIBSWRESAMPLE_VERSION_MAJOR 0
#define LIBSWRESAMPLE_VERSION_MINOR 10
#define LIBSWRESAMPLE_VERSION_MINOR 11
#define LIBSWRESAMPLE_VERSION_MICRO 100
#define LIBSWRESAMPLE_VERSION_INT AV_VERSION_INT(LIBSWRESAMPLE_VERSION_MAJOR, \
@ -45,6 +45,11 @@
//TODO use int resample ?
//long term TODO can we enable this dynamically?
enum SwrDitherType {
SWR_DITHER_NONE = 0,
SWR_DITHER_RECTANGULAR,
SWR_DITHER_NB, ///< not part of API/ABI
};
typedef struct SwrContext SwrContext;

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@ -49,6 +49,7 @@ struct SwrContext {
float rematrix_volume; ///< rematrixing volume coefficient
const int *channel_map; ///< channel index (or -1 if muted channel) map
int used_ch_count; ///< number of used input channels (mapped channel count if channel_map, otherwise in.ch_count)
enum SwrDitherType dither_method;
int int_bps; ///< internal bytes per sample
int resample_first; ///< 1 if resampling must come first, 0 if rematrixing
@ -61,6 +62,7 @@ struct SwrContext {
AudioData preout; ///< pre-output audio data: used for rematrix/resample
AudioData out; ///< converted output audio data
AudioData in_buffer; ///< cached audio data (convert and resample purpose)
AudioData dither; ///< cached audio data (convert and resample purpose)
int in_buffer_index; ///< cached buffer position
int in_buffer_count; ///< cached buffer length
int resample_in_constraint; ///< 1 if the input end was reach before the output end, 0 otherwise
@ -89,5 +91,8 @@ int swri_resample_double(struct ResampleContext *c,double *dst, const double *
int swri_rematrix_init(SwrContext *s);
int swri_rematrix(SwrContext *s, AudioData *out, AudioData *in, int len, int mustcopy);
void swri_sum2(enum AVSampleFormat format, void *dst, const void *src0, const void *src1, float coef0, float coef1, int len);
void swri_get_dither(void *dst, int len, unsigned seed, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, enum SwrDitherType type);
#endif