/* * 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,};