| /* |
| * 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/mem.h" |
| #include "libavutil/opt.h" |
| #include "audio.h" |
| #include "avfilter.h" |
| #include "internal.h" |
| |
| #define BINS 32768 |
| |
| typedef struct ChannelStats { |
| uint64_t nb_samples; |
| uint64_t blknum; |
| float peak; |
| float sum; |
| uint32_t peaks[BINS+1]; |
| uint32_t rms[BINS+1]; |
| } ChannelStats; |
| |
| typedef struct DRMeterContext { |
| const AVClass *class; |
| ChannelStats *chstats; |
| int nb_channels; |
| int64_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 config_output(AVFilterLink *outlink) |
| { |
| DRMeterContext *s = outlink->src->priv; |
| |
| s->chstats = av_calloc(outlink->ch_layout.nb_channels, sizeof(*s->chstats)); |
| if (!s->chstats) |
| return AVERROR(ENOMEM); |
| s->nb_channels = outlink->ch_layout.nb_channels; |
| s->tc_samples = lrint(s->time_constant * outlink->sample_rate); |
| |
| return 0; |
| } |
| |
| static void finish_block(ChannelStats *p) |
| { |
| int peak_bin, rms_bin; |
| float peak, rms; |
| |
| rms = sqrtf(2.f * p->sum / p->nb_samples); |
| peak = p->peak; |
| rms_bin = av_clip(lrintf(rms * BINS), 0, BINS); |
| peak_bin = av_clip(lrintf(peak * BINS), 0, BINS); |
| 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) |
| { |
| p->peak = fmaxf(fabsf(sample), p->peak); |
| p->sum += sample * sample; |
| p->nb_samples++; |
| if (p->nb_samples >= s->tc_samples) |
| finish_block(p); |
| } |
| |
| static int filter_frame(AVFilterLink *inlink, AVFrame *buf) |
| { |
| DRMeterContext *s = inlink->dst->priv; |
| const int channels = s->nb_channels; |
| |
| switch (inlink->format) { |
| case AV_SAMPLE_FMT_FLTP: |
| for (int c = 0; c < channels; c++) { |
| ChannelStats *p = &s->chstats[c]; |
| const float *src = (const float *)buf->extended_data[c]; |
| |
| for (int 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 (int i = 0; i < buf->nb_samples; i++) { |
| for (int 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.f; |
| |
| for (int ch = 0; ch < s->nb_channels; ch++) { |
| ChannelStats *p = &s->chstats[ch]; |
| float chdr, secondpeak, rmssum = 0.f; |
| int first = 0, last = lrintf(0.2f * p->blknum); |
| int peak_bin = BINS; |
| |
| if (!p->nb_samples) { |
| av_log(ctx, AV_LOG_INFO, "No data, dynamic range not meassurable\n"); |
| return; |
| } |
| |
| if (p->nb_samples) |
| finish_block(p); |
| |
| for (int i = BINS; i >= 0; i--) { |
| if (p->peaks[i]) { |
| if (first || p->peaks[i] > 1) { |
| peak_bin = i; |
| break; |
| } |
| first = 1; |
| } |
| } |
| |
| secondpeak = peak_bin / (float)BINS; |
| |
| for (int64_t i = BINS, j = 0; i >= 0 && j < last; i--) { |
| if (p->rms[i]) { |
| rmssum += SQR(i / (float)BINS) * p->rms[i]; |
| j += p->rms[i]; |
| } |
| } |
| |
| chdr = 20.f * log10f(secondpeak / sqrtf(rmssum / (float)last)); |
| dr += chdr; |
| av_log(ctx, AV_LOG_INFO, "Channel %d: DR: %g\n", ch + 1, chdr); |
| } |
| |
| av_log(ctx, AV_LOG_INFO, "Overall DR: %g\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, |
| }, |
| }; |
| |
| static const AVFilterPad drmeter_outputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_AUDIO, |
| .config_props = config_output, |
| }, |
| }; |
| |
| const AVFilter ff_af_drmeter = { |
| .name = "drmeter", |
| .description = NULL_IF_CONFIG_SMALL("Measure audio dynamic range."), |
| .priv_size = sizeof(DRMeterContext), |
| .priv_class = &drmeter_class, |
| .uninit = uninit, |
| .flags = AVFILTER_FLAG_METADATA_ONLY, |
| FILTER_INPUTS(drmeter_inputs), |
| FILTER_OUTPUTS(drmeter_outputs), |
| FILTER_SAMPLEFMTS(AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_FLT), |
| }; |