| /* |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg 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. |
| * |
| * FFmpeg 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 FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "libavutil/ffmath.h" |
| #include "libavutil/opt.h" |
| #include "avfilter.h" |
| #include "audio.h" |
| |
| typedef struct AudioDynamicSmoothContext { |
| const AVClass *class; |
| |
| double sensitivity; |
| double basefreq; |
| |
| AVFrame *coeffs; |
| } AudioDynamicSmoothContext; |
| |
| static int config_input(AVFilterLink *inlink) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| AudioDynamicSmoothContext *s = ctx->priv; |
| |
| s->coeffs = ff_get_audio_buffer(inlink, 3); |
| if (!s->coeffs) |
| return AVERROR(ENOMEM); |
| |
| return 0; |
| } |
| |
| static int filter_frame(AVFilterLink *inlink, AVFrame *in) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| AVFilterLink *outlink = ctx->outputs[0]; |
| AudioDynamicSmoothContext *s = ctx->priv; |
| const double sensitivity = s->sensitivity; |
| const double wc = s->basefreq / in->sample_rate; |
| AVFrame *out; |
| |
| if (av_frame_is_writable(in)) { |
| out = in; |
| } else { |
| out = ff_get_audio_buffer(outlink, in->nb_samples); |
| if (!out) { |
| av_frame_free(&in); |
| return AVERROR(ENOMEM); |
| } |
| av_frame_copy_props(out, in); |
| } |
| |
| for (int ch = 0; ch < out->ch_layout.nb_channels; ch++) { |
| const double *src = (const double *)in->extended_data[ch]; |
| double *dst = (double *)out->extended_data[ch]; |
| double *coeffs = (double *)s->coeffs->extended_data[ch]; |
| double low1 = coeffs[0]; |
| double low2 = coeffs[1]; |
| double inz = coeffs[2]; |
| |
| for (int n = 0; n < out->nb_samples; n++) { |
| double low1z = low1; |
| double low2z = low2; |
| double bandz = low2z - low1z; |
| double wd = wc + sensitivity * fabs(bandz); |
| double g = fmin(1., wd * (5.9948827 + wd * (-11.969296 + wd * 15.959062))); |
| |
| low1 = low1z + g * (0.5 * (src[n] + inz) - low1z); |
| low2 = low2z + g * (0.5 * (low1 + low1z) - low2z); |
| inz = src[n]; |
| dst[n] = ctx->is_disabled ? src[n] : low2; |
| } |
| |
| coeffs[0] = low1; |
| coeffs[1] = low2; |
| coeffs[2] = inz; |
| } |
| |
| if (out != in) |
| av_frame_free(&in); |
| return ff_filter_frame(outlink, out); |
| } |
| |
| static av_cold void uninit(AVFilterContext *ctx) |
| { |
| AudioDynamicSmoothContext *s = ctx->priv; |
| |
| av_frame_free(&s->coeffs); |
| } |
| |
| #define OFFSET(x) offsetof(AudioDynamicSmoothContext, x) |
| #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM |
| |
| static const AVOption adynamicsmooth_options[] = { |
| { "sensitivity", "set smooth sensitivity", OFFSET(sensitivity), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 0, 1000000, FLAGS }, |
| { "basefreq", "set base frequency", OFFSET(basefreq), AV_OPT_TYPE_DOUBLE, {.dbl=22050}, 2, 1000000, FLAGS }, |
| { NULL } |
| }; |
| |
| AVFILTER_DEFINE_CLASS(adynamicsmooth); |
| |
| static const AVFilterPad inputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_AUDIO, |
| .filter_frame = filter_frame, |
| .config_props = config_input, |
| }, |
| }; |
| |
| const AVFilter ff_af_adynamicsmooth = { |
| .name = "adynamicsmooth", |
| .description = NULL_IF_CONFIG_SMALL("Apply Dynamic Smoothing of input audio."), |
| .priv_size = sizeof(AudioDynamicSmoothContext), |
| .priv_class = &adynamicsmooth_class, |
| .uninit = uninit, |
| FILTER_INPUTS(inputs), |
| FILTER_OUTPUTS(ff_audio_default_filterpad), |
| FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_DBLP), |
| .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL, |
| .process_command = ff_filter_process_command, |
| }; |