1/* 2 * Copyright (C) 2012-2013 Michael Niedermayer (michaelni@gmx.at) 3 * 4 * This file is part of libswresample 5 * 6 * libswresample is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * libswresample is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with libswresample; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21#include "libavutil/avassert.h" 22#include "swresample_internal.h" 23 24#include "noise_shaping_data.c" 25 26void swri_get_dither(SwrContext *s, void *dst, int len, unsigned seed, enum AVSampleFormat noise_fmt) { 27 double scale = s->dither.noise_scale; 28#define TMP_EXTRA 2 29 double *tmp = av_malloc_array(len + TMP_EXTRA, sizeof(double)); 30 int i; 31 32 for(i=0; i<len + TMP_EXTRA; i++){ 33 double v; 34 seed = seed* 1664525 + 1013904223; 35 36 switch(s->dither.method){ 37 case SWR_DITHER_RECTANGULAR: v= ((double)seed) / UINT_MAX - 0.5; break; 38 default: 39 av_assert0(s->dither.method < SWR_DITHER_NB); 40 v = ((double)seed) / UINT_MAX; 41 seed = seed*1664525 + 1013904223; 42 v-= ((double)seed) / UINT_MAX; 43 break; 44 } 45 tmp[i] = v; 46 } 47 48 for(i=0; i<len; i++){ 49 double v; 50 51 switch(s->dither.method){ 52 default: 53 av_assert0(s->dither.method < SWR_DITHER_NB); 54 v = tmp[i]; 55 break; 56 case SWR_DITHER_TRIANGULAR_HIGHPASS : 57 v = (- tmp[i] + 2*tmp[i+1] - tmp[i+2]) / sqrt(6); 58 break; 59 } 60 61 v*= scale; 62 63 switch(noise_fmt){ 64 case AV_SAMPLE_FMT_S16P: ((int16_t*)dst)[i] = v; break; 65 case AV_SAMPLE_FMT_S32P: ((int32_t*)dst)[i] = v; break; 66 case AV_SAMPLE_FMT_FLTP: ((float *)dst)[i] = v; break; 67 case AV_SAMPLE_FMT_DBLP: ((double *)dst)[i] = v; break; 68 default: av_assert0(0); 69 } 70 } 71 72 av_free(tmp); 73} 74 75int swri_dither_init(SwrContext *s, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt) 76{ 77 int i; 78 double scale = 0; 79 80 if (s->dither.method > SWR_DITHER_TRIANGULAR_HIGHPASS && s->dither.method <= SWR_DITHER_NS) 81 return AVERROR(EINVAL); 82 83 out_fmt = av_get_packed_sample_fmt(out_fmt); 84 in_fmt = av_get_packed_sample_fmt( in_fmt); 85 86 if(in_fmt == AV_SAMPLE_FMT_FLT || in_fmt == AV_SAMPLE_FMT_DBL){ 87 if(out_fmt == AV_SAMPLE_FMT_S32) scale = 1.0/(1L<<31); 88 if(out_fmt == AV_SAMPLE_FMT_S16) scale = 1.0/(1L<<15); 89 if(out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1.0/(1L<< 7); 90 } 91 if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_S32 && (s->dither.output_sample_bits&31)) scale = 1; 92 if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_S16) scale = 1L<<16; 93 if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<24; 94 if(in_fmt == AV_SAMPLE_FMT_S16 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<8; 95 96 scale *= s->dither.scale; 97 98 if (out_fmt == AV_SAMPLE_FMT_S32 && s->dither.output_sample_bits) 99 scale *= 1<<(32-s->dither.output_sample_bits); 100 101 s->dither.ns_pos = 0; 102 s->dither.noise_scale= scale; 103 s->dither.ns_scale = scale; 104 s->dither.ns_scale_1 = scale ? 1/scale : 0; 105 memset(s->dither.ns_errors, 0, sizeof(s->dither.ns_errors)); 106 for (i=0; filters[i].coefs; i++) { 107 const filter_t *f = &filters[i]; 108 if (fabs(s->out_sample_rate - f->rate) / f->rate <= .05 && f->name == s->dither.method) { 109 int j; 110 s->dither.ns_taps = f->len; 111 for (j=0; j<f->len; j++) 112 s->dither.ns_coeffs[j] = f->coefs[j]; 113 s->dither.ns_scale_1 *= 1 - exp(f->gain_cB * M_LN10 * 0.005) * 2 / (1<<(8*av_get_bytes_per_sample(out_fmt))); 114 break; 115 } 116 } 117 if (!filters[i].coefs && s->dither.method > SWR_DITHER_NS) { 118 av_log(s, AV_LOG_WARNING, "Requested noise shaping dither not available at this sampling rate, using triangular hp dither\n"); 119 s->dither.method = SWR_DITHER_TRIANGULAR_HIGHPASS; 120 } 121 122 av_assert0(!s->preout.count); 123 s->dither.noise = s->preout; 124 s->dither.temp = s->preout; 125 if (s->dither.method > SWR_DITHER_NS) { 126 s->dither.noise.bps = 4; 127 s->dither.noise.fmt = AV_SAMPLE_FMT_FLTP; 128 s->dither.noise_scale = 1; 129 } 130 131 return 0; 132} 133 134#define TEMPLATE_DITHER_S16 135#include "dither_template.c" 136#undef TEMPLATE_DITHER_S16 137 138#define TEMPLATE_DITHER_S32 139#include "dither_template.c" 140#undef TEMPLATE_DITHER_S32 141 142#define TEMPLATE_DITHER_FLT 143#include "dither_template.c" 144#undef TEMPLATE_DITHER_FLT 145 146#define TEMPLATE_DITHER_DBL 147#include "dither_template.c" 148#undef TEMPLATE_DITHER_DBL 149