/* * Copyright (c) 2018 Paul B Mahol * * 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 <float.h> #include "libavutil/ffmath.h" #include "libavutil/opt.h" #include "audio.h" #include "avfilter.h" #include "internal.h" typedef struct ChannelStats { uint64_t nb_samples; uint64_t blknum; float peak; float sum; uint32_t peaks[10001]; uint32_t rms[10001]; } ChannelStats; typedef struct DRMeterContext { const AVClass *class; ChannelStats *chstats; int nb_channels; uint64_t tc_samples; double time_constant; } DRMeterContext; #define OFFSET(x) offsetof(DRMeterContext, x) #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM static const AVOption drmeter_options[] = { { "length", "set the window length", OFFSET(time_constant), AV_OPT_TYPE_DOUBLE, {.dbl=3}, .01, 10, FLAGS }, { NULL } }; AVFILTER_DEFINE_CLASS(drmeter); static int query_formats(AVFilterContext *ctx) { AVFilterFormats *formats; AVFilterChannelLayouts *layouts; static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_NONE }; int ret; layouts = ff_all_channel_counts(); if (!layouts) return AVERROR(ENOMEM); ret = ff_set_common_channel_layouts(ctx, layouts); if (ret < 0) return ret; formats = ff_make_format_list(sample_fmts); if (!formats) return AVERROR(ENOMEM); ret = ff_set_common_formats(ctx, formats); if (ret < 0) return ret; formats = ff_all_samplerates(); if (!formats) return AVERROR(ENOMEM); return ff_set_common_samplerates(ctx, formats); } static int config_output(AVFilterLink *outlink) { DRMeterContext *s = outlink->src->priv; s->chstats = av_calloc(sizeof(*s->chstats), outlink->channels); if (!s->chstats) return AVERROR(ENOMEM); s->nb_channels = outlink->channels; s->tc_samples = s->time_constant * outlink->sample_rate + .5; return 0; } static void finish_block(ChannelStats *p) { int peak_bin, rms_bin; float peak, rms; rms = sqrt(2 * p->sum / p->nb_samples); peak = p->peak; rms_bin = av_clip(rms * 10000, 0, 10000); peak_bin = av_clip(peak * 10000, 0, 10000); p->rms[rms_bin]++; p->peaks[peak_bin]++; p->peak = 0; p->sum = 0; p->nb_samples = 0; p->blknum++; } static void update_stat(DRMeterContext *s, ChannelStats *p, float sample) { if (p->nb_samples >= s->tc_samples) { finish_block(p); } p->peak = FFMAX(FFABS(sample), p->peak); p->sum += sample * sample; p->nb_samples++; } static int filter_frame(AVFilterLink *inlink, AVFrame *buf) { DRMeterContext *s = inlink->dst->priv; const int channels = s->nb_channels; int i, c; switch (inlink->format) { case AV_SAMPLE_FMT_FLTP: for (c = 0; c < channels; c++) { ChannelStats *p = &s->chstats[c]; const float *src = (const float *)buf->extended_data[c]; for (i = 0; i < buf->nb_samples; i++, src++) update_stat(s, p, *src); } break; case AV_SAMPLE_FMT_FLT: { const float *src = (const float *)buf->extended_data[0]; for (i = 0; i < buf->nb_samples; i++) { for (c = 0; c < channels; c++, src++) update_stat(s, &s->chstats[c], *src); }} break; } return ff_filter_frame(inlink->dst->outputs[0], buf); } #define SQR(a) ((a)*(a)) static void print_stats(AVFilterContext *ctx) { DRMeterContext *s = ctx->priv; float dr = 0; int ch; for (ch = 0; ch < s->nb_channels; ch++) { ChannelStats *p = &s->chstats[ch]; float chdr, secondpeak, rmssum = 0; int i, j, first = 0; finish_block(p); for (i = 0; i <= 10000; i++) { if (p->peaks[10000 - i]) { if (first) break; first = 1; } } secondpeak = (10000 - i) / 10000.; for (i = 10000, j = 0; i >= 0 && j < 0.2 * p->blknum; i--) { if (p->rms[i]) { rmssum += SQR(i / 10000.) * p->rms[i]; j += p->rms[i]; } } chdr = 20 * log10(secondpeak / sqrt(rmssum / (0.2 * p->blknum))); dr += chdr; av_log(ctx, AV_LOG_INFO, "Channel %d: DR: %.1f\n", ch + 1, chdr); } av_log(ctx, AV_LOG_INFO, "Overall DR: %.1f\n", dr / s->nb_channels); } static av_cold void uninit(AVFilterContext *ctx) { DRMeterContext *s = ctx->priv; if (s->nb_channels) print_stats(ctx); av_freep(&s->chstats); } static const AVFilterPad drmeter_inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, .filter_frame = filter_frame, }, { NULL } }; static const AVFilterPad drmeter_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, .config_props = config_output, }, { NULL } }; AVFilter ff_af_drmeter = { .name = "drmeter", .description = NULL_IF_CONFIG_SMALL("Measure audio dynamic range."), .query_formats = query_formats, .priv_size = sizeof(DRMeterContext), .priv_class = &drmeter_class, .uninit = uninit, .inputs = drmeter_inputs, .outputs = drmeter_outputs, };