diff options
Diffstat (limited to 'libavfilter/af_adynamicsmooth.c')
| -rw-r--r-- | libavfilter/af_adynamicsmooth.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/libavfilter/af_adynamicsmooth.c b/libavfilter/af_adynamicsmooth.c new file mode 100644 index 0000000000..4e00fecc6a --- /dev/null +++ b/libavfilter/af_adynamicsmooth.c @@ -0,0 +1,142 @@ +/* + * 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" +#include "formats.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->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, + }, +}; + +static const AVFilterPad outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + }, +}; + +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(outputs), + FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_DBLP), + .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL, + .process_command = ff_filter_process_command, +}; |