| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * Copyright (c) 2013-2020 Michael Barbour <barbour.michael.0@gmail.com> | ||
| 3 | * Copyright (c) 2021 Paul B Mahol | ||
| 4 | * | ||
| 5 | * This file is part of FFmpeg. | ||
| 6 | * | ||
| 7 | * FFmpeg is free software; you can redistribute it and/or | ||
| 8 | * modify it under the terms of the GNU Lesser General Public | ||
| 9 | * License as published by the Free Software Foundation; either | ||
| 10 | * version 2.1 of the License, or (at your option) any later version. | ||
| 11 | * | ||
| 12 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 15 | * Lesser General Public License for more details. | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU Lesser General Public | ||
| 18 | * License along with FFmpeg; if not, write to the Free Software | ||
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 20 | */ | ||
| 21 | |||
| 22 | #include "libavutil/channel_layout.h" | ||
| 23 | #include "libavutil/ffmath.h" | ||
| 24 | #include "libavutil/lfg.h" | ||
| 25 | #include "libavutil/mem.h" | ||
| 26 | #include "libavutil/random_seed.h" | ||
| 27 | #include "libavutil/opt.h" | ||
| 28 | #include "avfilter.h" | ||
| 29 | #include "audio.h" | ||
| 30 | #include "filters.h" | ||
| 31 | |||
| 32 | #define MAX_STAGES 16 | ||
| 33 | #define FILTER_FC 1100.0 | ||
| 34 | #define RT60_LF 0.1 | ||
| 35 | #define RT60_HF 0.008 | ||
| 36 | |||
| 37 | typedef struct APContext { | ||
| 38 | int len, p; | ||
| 39 | double *mx, *my; | ||
| 40 | double b0, b1, a0, a1; | ||
| 41 | } APContext; | ||
| 42 | |||
| 43 | typedef struct ADecorrelateContext { | ||
| 44 | const AVClass *class; | ||
| 45 | |||
| 46 | int stages; | ||
| 47 | int64_t seed; | ||
| 48 | |||
| 49 | int nb_channels; | ||
| 50 | APContext (*ap)[MAX_STAGES]; | ||
| 51 | |||
| 52 | AVLFG c; | ||
| 53 | |||
| 54 | void (*filter_channel)(AVFilterContext *ctx, | ||
| 55 | int channel, | ||
| 56 | AVFrame *in, AVFrame *out); | ||
| 57 | } ADecorrelateContext; | ||
| 58 | |||
| 59 | ✗ | static int ap_init(APContext *ap, int fs, double delay) | |
| 60 | { | ||
| 61 | ✗ | const int delay_samples = lrint(round(delay * fs)); | |
| 62 | ✗ | const double gain_lf = -60.0 / (RT60_LF * fs) * delay_samples; | |
| 63 | ✗ | const double gain_hf = -60.0 / (RT60_HF * fs) * delay_samples; | |
| 64 | ✗ | const double w0 = 2.0 * M_PI * FILTER_FC / fs; | |
| 65 | ✗ | const double t = tan(w0 / 2.0); | |
| 66 | ✗ | const double g_hf = ff_exp10(gain_hf / 20.0); | |
| 67 | ✗ | const double gd = ff_exp10((gain_lf-gain_hf) / 20.0); | |
| 68 | ✗ | const double sgd = sqrt(gd); | |
| 69 | |||
| 70 | ✗ | ap->len = delay_samples + 1; | |
| 71 | ✗ | ap->p = 0; | |
| 72 | ✗ | ap->mx = av_calloc(ap->len, sizeof(*ap->mx)); | |
| 73 | ✗ | ap->my = av_calloc(ap->len, sizeof(*ap->my)); | |
| 74 | ✗ | if (!ap->mx || !ap->my) | |
| 75 | ✗ | return AVERROR(ENOMEM); | |
| 76 | |||
| 77 | ✗ | ap->a0 = t + sgd; | |
| 78 | ✗ | ap->a1 = (t - sgd) / ap->a0; | |
| 79 | ✗ | ap->b0 = (gd*t - sgd) / ap->a0 * g_hf; | |
| 80 | ✗ | ap->b1 = (gd*t + sgd) / ap->a0 * g_hf; | |
| 81 | ✗ | ap->a0 = 1.0; | |
| 82 | |||
| 83 | ✗ | return 0; | |
| 84 | } | ||
| 85 | |||
| 86 | ✗ | static void ap_free(APContext *ap) | |
| 87 | { | ||
| 88 | ✗ | av_freep(&ap->mx); | |
| 89 | ✗ | av_freep(&ap->my); | |
| 90 | ✗ | } | |
| 91 | |||
| 92 | ✗ | static double ap_run(APContext *ap, double x) | |
| 93 | { | ||
| 94 | ✗ | const int i0 = ((ap->p < 1) ? ap->len : ap->p)-1, i_n1 = ap->p, i_n2 = (ap->p+1 >= ap->len) ? 0 : ap->p+1; | |
| 95 | ✗ | const double r = ap->b1*x + ap->b0*ap->mx[i0] + ap->a1*ap->mx[i_n2] + ap->a0*ap->mx[i_n1] - | |
| 96 | ✗ | ap->a1*ap->my[i0] - ap->b0*ap->my[i_n2] - ap->b1*ap->my[i_n1]; | |
| 97 | |||
| 98 | ✗ | ap->mx[ap->p] = x; | |
| 99 | ✗ | ap->my[ap->p] = r; | |
| 100 | ✗ | ap->p = (ap->p+1 >= ap->len) ? 0 : ap->p+1; | |
| 101 | |||
| 102 | ✗ | return r; | |
| 103 | } | ||
| 104 | |||
| 105 | ✗ | static void filter_channel_dbl(AVFilterContext *ctx, int ch, | |
| 106 | AVFrame *in, AVFrame *out) | ||
| 107 | { | ||
| 108 | ✗ | ADecorrelateContext *s = ctx->priv; | |
| 109 | ✗ | const double *src = (const double *)in->extended_data[ch]; | |
| 110 | ✗ | double *dst = (double *)out->extended_data[ch]; | |
| 111 | ✗ | const int nb_samples = in->nb_samples; | |
| 112 | ✗ | const int stages = s->stages; | |
| 113 | ✗ | APContext *ap0 = &s->ap[ch][0]; | |
| 114 | |||
| 115 | ✗ | for (int n = 0; n < nb_samples; n++) { | |
| 116 | ✗ | dst[n] = ap_run(ap0, src[n]); | |
| 117 | ✗ | for (int i = 1; i < stages; i++) { | |
| 118 | ✗ | APContext *ap = &s->ap[ch][i]; | |
| 119 | |||
| 120 | ✗ | dst[n] = ap_run(ap, dst[n]); | |
| 121 | } | ||
| 122 | } | ||
| 123 | ✗ | } | |
| 124 | |||
| 125 | ✗ | static int config_input(AVFilterLink *inlink) | |
| 126 | { | ||
| 127 | ✗ | AVFilterContext *ctx = inlink->dst; | |
| 128 | ✗ | ADecorrelateContext *s = ctx->priv; | |
| 129 | int ret; | ||
| 130 | |||
| 131 | ✗ | if (s->seed == -1) | |
| 132 | ✗ | s->seed = av_get_random_seed(); | |
| 133 | ✗ | av_lfg_init(&s->c, s->seed); | |
| 134 | |||
| 135 | ✗ | s->nb_channels = inlink->ch_layout.nb_channels; | |
| 136 | ✗ | s->ap = av_calloc(inlink->ch_layout.nb_channels, sizeof(*s->ap)); | |
| 137 | ✗ | if (!s->ap) | |
| 138 | ✗ | return AVERROR(ENOMEM); | |
| 139 | |||
| 140 | ✗ | for (int i = 0; i < inlink->ch_layout.nb_channels; i++) { | |
| 141 | ✗ | for (int j = 0; j < s->stages; j++) { | |
| 142 | ✗ | ret = ap_init(&s->ap[i][j], inlink->sample_rate, | |
| 143 | ✗ | (double)av_lfg_get(&s->c) / 0xffffffff * 2.2917e-3 + 0.83333e-3); | |
| 144 | ✗ | if (ret < 0) | |
| 145 | ✗ | return ret; | |
| 146 | } | ||
| 147 | } | ||
| 148 | |||
| 149 | ✗ | s->filter_channel = filter_channel_dbl; | |
| 150 | |||
| 151 | ✗ | return 0; | |
| 152 | } | ||
| 153 | |||
| 154 | typedef struct ThreadData { | ||
| 155 | AVFrame *in, *out; | ||
| 156 | } ThreadData; | ||
| 157 | |||
| 158 | ✗ | static int filter_channels(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) | |
| 159 | { | ||
| 160 | ✗ | ADecorrelateContext *s = ctx->priv; | |
| 161 | ✗ | ThreadData *td = arg; | |
| 162 | ✗ | AVFrame *out = td->out; | |
| 163 | ✗ | AVFrame *in = td->in; | |
| 164 | ✗ | const int start = (in->ch_layout.nb_channels * jobnr) / nb_jobs; | |
| 165 | ✗ | const int end = (in->ch_layout.nb_channels * (jobnr+1)) / nb_jobs; | |
| 166 | |||
| 167 | ✗ | for (int ch = start; ch < end; ch++) | |
| 168 | ✗ | s->filter_channel(ctx, ch, in, out); | |
| 169 | |||
| 170 | ✗ | return 0; | |
| 171 | } | ||
| 172 | |||
| 173 | ✗ | static int filter_frame(AVFilterLink *inlink, AVFrame *in) | |
| 174 | { | ||
| 175 | ✗ | AVFilterContext *ctx = inlink->dst; | |
| 176 | ✗ | AVFilterLink *outlink = ctx->outputs[0]; | |
| 177 | AVFrame *out; | ||
| 178 | ThreadData td; | ||
| 179 | |||
| 180 | ✗ | if (av_frame_is_writable(in)) { | |
| 181 | ✗ | out = in; | |
| 182 | } else { | ||
| 183 | ✗ | out = ff_get_audio_buffer(outlink, in->nb_samples); | |
| 184 | ✗ | if (!out) { | |
| 185 | ✗ | av_frame_free(&in); | |
| 186 | ✗ | return AVERROR(ENOMEM); | |
| 187 | } | ||
| 188 | ✗ | av_frame_copy_props(out, in); | |
| 189 | } | ||
| 190 | |||
| 191 | ✗ | td.in = in; td.out = out; | |
| 192 | ✗ | ff_filter_execute(ctx, filter_channels, &td, NULL, | |
| 193 | ✗ | FFMIN(inlink->ch_layout.nb_channels, ff_filter_get_nb_threads(ctx))); | |
| 194 | |||
| 195 | ✗ | if (out != in) | |
| 196 | ✗ | av_frame_free(&in); | |
| 197 | ✗ | return ff_filter_frame(outlink, out); | |
| 198 | } | ||
| 199 | |||
| 200 | ✗ | static av_cold void uninit(AVFilterContext *ctx) | |
| 201 | { | ||
| 202 | ✗ | ADecorrelateContext *s = ctx->priv; | |
| 203 | |||
| 204 | ✗ | if (s->ap) { | |
| 205 | ✗ | for (int ch = 0; ch < s->nb_channels; ch++) { | |
| 206 | ✗ | for (int stage = 0; stage < s->stages; stage++) | |
| 207 | ✗ | ap_free(&s->ap[ch][stage]); | |
| 208 | } | ||
| 209 | } | ||
| 210 | |||
| 211 | ✗ | av_freep(&s->ap); | |
| 212 | ✗ | } | |
| 213 | |||
| 214 | #define OFFSET(x) offsetof(ADecorrelateContext, x) | ||
| 215 | #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM | ||
| 216 | |||
| 217 | static const AVOption adecorrelate_options[] = { | ||
| 218 | { "stages", "set filtering stages", OFFSET(stages), AV_OPT_TYPE_INT, {.i64=6}, 1, MAX_STAGES, FLAGS }, | ||
| 219 | { "seed", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64=-1}, -1, UINT_MAX, FLAGS }, | ||
| 220 | { NULL } | ||
| 221 | }; | ||
| 222 | |||
| 223 | AVFILTER_DEFINE_CLASS(adecorrelate); | ||
| 224 | |||
| 225 | static const AVFilterPad inputs[] = { | ||
| 226 | { | ||
| 227 | .name = "default", | ||
| 228 | .type = AVMEDIA_TYPE_AUDIO, | ||
| 229 | .filter_frame = filter_frame, | ||
| 230 | .config_props = config_input, | ||
| 231 | }, | ||
| 232 | }; | ||
| 233 | |||
| 234 | const AVFilter ff_af_adecorrelate = { | ||
| 235 | .name = "adecorrelate", | ||
| 236 | .description = NULL_IF_CONFIG_SMALL("Apply decorrelation to input audio."), | ||
| 237 | .priv_size = sizeof(ADecorrelateContext), | ||
| 238 | .priv_class = &adecorrelate_class, | ||
| 239 | .uninit = uninit, | ||
| 240 | FILTER_INPUTS(inputs), | ||
| 241 | FILTER_OUTPUTS(ff_audio_default_filterpad), | ||
| 242 | FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_DBLP), | ||
| 243 | .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | | ||
| 244 | AVFILTER_FLAG_SLICE_THREADS, | ||
| 245 | }; | ||
| 246 |