| 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 | |
| 26 | void 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 | |
| 75 | int 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 |