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
swri_get_dither(SwrContext * s,void * dst,int len,unsigned seed,enum AVSampleFormat noise_fmt)26 int 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 if (!tmp)
33 return AVERROR(ENOMEM);
34
35 for(i=0; i<len + TMP_EXTRA; i++){
36 double v;
37 seed = seed* 1664525 + 1013904223;
38
39 switch(s->dither.method){
40 case SWR_DITHER_RECTANGULAR: v= ((double)seed) / UINT_MAX - 0.5; break;
41 default:
42 av_assert0(s->dither.method < SWR_DITHER_NB);
43 v = ((double)seed) / UINT_MAX;
44 seed = seed*1664525 + 1013904223;
45 v-= ((double)seed) / UINT_MAX;
46 break;
47 }
48 tmp[i] = v;
49 }
50
51 for(i=0; i<len; i++){
52 double v;
53
54 switch(s->dither.method){
55 default:
56 av_assert0(s->dither.method < SWR_DITHER_NB);
57 v = tmp[i];
58 break;
59 case SWR_DITHER_TRIANGULAR_HIGHPASS :
60 v = (- tmp[i] + 2*tmp[i+1] - tmp[i+2]) / sqrt(6);
61 break;
62 }
63
64 v*= scale;
65
66 switch(noise_fmt){
67 case AV_SAMPLE_FMT_S16P: ((int16_t*)dst)[i] = v; break;
68 case AV_SAMPLE_FMT_S32P: ((int32_t*)dst)[i] = v; break;
69 case AV_SAMPLE_FMT_FLTP: ((float *)dst)[i] = v; break;
70 case AV_SAMPLE_FMT_DBLP: ((double *)dst)[i] = v; break;
71 default: av_assert0(0);
72 }
73 }
74
75 av_free(tmp);
76 return 0;
77 }
78
swri_dither_init(SwrContext * s,enum AVSampleFormat out_fmt,enum AVSampleFormat in_fmt)79 av_cold int swri_dither_init(SwrContext *s, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt)
80 {
81 int i;
82 double scale = 0;
83
84 if (s->dither.method > SWR_DITHER_TRIANGULAR_HIGHPASS && s->dither.method <= SWR_DITHER_NS)
85 return AVERROR(EINVAL);
86
87 out_fmt = av_get_packed_sample_fmt(out_fmt);
88 in_fmt = av_get_packed_sample_fmt( in_fmt);
89
90 if(in_fmt == AV_SAMPLE_FMT_FLT || in_fmt == AV_SAMPLE_FMT_DBL){
91 if(out_fmt == AV_SAMPLE_FMT_S32) scale = 1.0/(1LL<<31);
92 if(out_fmt == AV_SAMPLE_FMT_S16) scale = 1.0/(1LL<<15);
93 if(out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1.0/(1LL<< 7);
94 }
95 if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_S32 && (s->dither.output_sample_bits&31)) scale = 1;
96 if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_S16) scale = 1<<16;
97 if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1<<24;
98 if(in_fmt == AV_SAMPLE_FMT_S16 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1<<8;
99
100 scale *= s->dither.scale;
101
102 if (out_fmt == AV_SAMPLE_FMT_S32 && s->dither.output_sample_bits)
103 scale *= 1<<(32-s->dither.output_sample_bits);
104
105 if (scale == 0) {
106 s->dither.method = 0;
107 return 0;
108 }
109
110 s->dither.ns_pos = 0;
111 s->dither.noise_scale= scale;
112 s->dither.ns_scale = scale;
113 s->dither.ns_scale_1 = scale ? 1/scale : 0;
114 memset(s->dither.ns_errors, 0, sizeof(s->dither.ns_errors));
115 for (i=0; filters[i].coefs; i++) {
116 const filter_t *f = &filters[i];
117 if (llabs(s->out_sample_rate - f->rate)*20 <= f->rate && f->name == s->dither.method) {
118 int j;
119 s->dither.ns_taps = f->len;
120 for (j=0; j<f->len; j++)
121 s->dither.ns_coeffs[j] = f->coefs[j];
122 s->dither.ns_scale_1 *= 1 - exp(f->gain_cB * M_LN10 * 0.005) * 2 / (1<<(8*av_get_bytes_per_sample(out_fmt)));
123 break;
124 }
125 }
126 if (!filters[i].coefs && s->dither.method > SWR_DITHER_NS) {
127 av_log(s, AV_LOG_WARNING, "Requested noise shaping dither not available at this sampling rate, using triangular hp dither\n");
128 s->dither.method = SWR_DITHER_TRIANGULAR_HIGHPASS;
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