[FFmpeg-devel] [PATCH] avfilter: add audio signal to distortion ratio filter
Paul B Mahol
onemda at gmail.com
Sun Sep 12 21:44:01 EEST 2021
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
doc/filters.texi | 7 ++
libavfilter/Makefile | 1 +
libavfilter/af_asdr.c | 237 +++++++++++++++++++++++++++++++++++++++
libavfilter/allfilters.c | 1 +
4 files changed, 246 insertions(+)
create mode 100644 libavfilter/af_asdr.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 8f20ccf8c6..6af7344820 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2531,6 +2531,13 @@ noise removed from input signal.
This filter supports the all above options as @ref{commands}.
+ at section asdr
+Measure Audio Signal-to-Distortion Ratio.
+
+This filter takes two audio streams for input, and outputs first
+audio stream.
+Results are in dB per channel at end of either input.
+
@section asetnsamples
Set the number of samples per each output audio frame.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 76c65c3f42..865252ef3f 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -82,6 +82,7 @@ OBJS-$(CONFIG_AREALTIME_FILTER) += f_realtime.o
OBJS-$(CONFIG_ARESAMPLE_FILTER) += af_aresample.o
OBJS-$(CONFIG_AREVERSE_FILTER) += f_reverse.o
OBJS-$(CONFIG_ARNNDN_FILTER) += af_arnndn.o
+OBJS-$(CONFIG_ASDR_FILTER) += af_asdr.o
OBJS-$(CONFIG_ASEGMENT_FILTER) += f_segment.o
OBJS-$(CONFIG_ASELECT_FILTER) += f_select.o
OBJS-$(CONFIG_ASENDCMD_FILTER) += f_sendcmd.o
diff --git a/libavfilter/af_asdr.c b/libavfilter/af_asdr.c
new file mode 100644
index 0000000000..220da74a85
--- /dev/null
+++ b/libavfilter/af_asdr.c
@@ -0,0 +1,237 @@
+/*
+ * Copyright (c) 2021 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 "libavutil/audio_fifo.h"
+#include "libavutil/channel_layout.h"
+#include "libavutil/common.h"
+#include "libavutil/opt.h"
+
+#include "audio.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "filters.h"
+#include "internal.h"
+
+typedef struct AudioSDRContext {
+ int channels;
+ int64_t pts;
+ double *sum_u;
+ double *sum_uv;
+
+ AVFrame *cache[2];
+
+ AVAudioFifo *fifo[2];
+} AudioSDRContext;
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVSampleFormat sample_fmts[] = {
+ AV_SAMPLE_FMT_DBLP,
+ AV_SAMPLE_FMT_NONE
+ };
+ int ret = ff_set_common_all_channel_counts(ctx);
+ if (ret < 0)
+ return ret;
+
+ ret = ff_set_common_formats_from_list(ctx, sample_fmts);
+ if (ret < 0)
+ return ret;
+
+ return ff_set_common_all_samplerates(ctx);
+}
+
+static void sdr(AVFilterContext *ctx, const AVFrame *u, const AVFrame *v)
+{
+ AudioSDRContext *s = ctx->priv;
+
+ for (int ch = 0; ch < u->channels; ch++) {
+ const double *const us = (double *)u->extended_data[ch];
+ const double *const vs = (double *)v->extended_data[ch];
+ double sum_uv = s->sum_uv[ch];
+ double sum_u = s->sum_u[ch];
+
+ for (int n = 0; n < u->nb_samples; n++) {
+ sum_u += us[n] * us[n];
+ sum_uv += (us[n] - vs[n]) * (us[n] - vs[n]);
+ }
+
+ s->sum_uv[ch] = sum_uv;
+ s->sum_u[ch] = sum_u;
+ }
+}
+
+static int activate(AVFilterContext *ctx)
+{
+ AudioSDRContext *s = ctx->priv;
+ AVFrame *frame = NULL;
+ int ret, status;
+ int available;
+ int64_t pts;
+
+ FF_FILTER_FORWARD_STATUS_BACK_ALL(ctx->outputs[0], ctx);
+
+ for (int i = 0; i < 2; i++) {
+ ret = ff_inlink_consume_frame(ctx->inputs[i], &frame);
+ if (ret > 0) {
+ if (s->pts == AV_NOPTS_VALUE)
+ s->pts = frame->pts;
+ ret = av_audio_fifo_write(s->fifo[i], (void **)frame->extended_data,
+ frame->nb_samples);
+ av_frame_free(&frame);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ available = FFMIN(av_audio_fifo_size(s->fifo[0]), av_audio_fifo_size(s->fifo[1]));
+ if (available > 0) {
+ AVFrame *out;
+
+ if (!s->cache[0] || s->cache[0]->nb_samples < available) {
+ av_frame_free(&s->cache[0]);
+ s->cache[0] = ff_get_audio_buffer(ctx->outputs[0], available);
+ if (!s->cache[0])
+ return AVERROR(ENOMEM);
+ }
+
+ if (!s->cache[1] || s->cache[1]->nb_samples < available) {
+ av_frame_free(&s->cache[1]);
+ s->cache[1] = ff_get_audio_buffer(ctx->outputs[0], available);
+ if (!s->cache[1])
+ return AVERROR(ENOMEM);
+ }
+
+ ret = av_audio_fifo_peek(s->fifo[0], (void **)s->cache[0]->extended_data, available);
+ if (ret < 0)
+ return ret;
+
+ ret = av_audio_fifo_peek(s->fifo[1], (void **)s->cache[1]->extended_data, available);
+ if (ret < 0)
+ return ret;
+
+ sdr(ctx, s->cache[0], s->cache[1]);
+
+ out = av_frame_clone(s->cache[0]);
+ out->nb_samples = available;
+ out->pts = s->pts;
+ s->pts += available;
+
+ av_audio_fifo_drain(s->fifo[0], available);
+ av_audio_fifo_drain(s->fifo[1], available);
+
+ return ff_filter_frame(ctx->outputs[0], out);
+ }
+
+ for (int i = 0; i < 2; i++) {
+ if (ff_inlink_acknowledge_status(ctx->inputs[i], &status, &pts)) {
+ ff_outlink_set_status(ctx->outputs[0], status, pts);
+ return 0;
+ }
+ }
+
+ if (av_audio_fifo_size(s->fifo[0]) > 0 &&
+ av_audio_fifo_size(s->fifo[1]) > 0) {
+ ff_filter_set_ready(ctx, 10);
+ return 0;
+ }
+
+ if (ff_outlink_frame_wanted(ctx->outputs[0])) {
+ for (int i = 0; i < 2; i++) {
+ if (av_audio_fifo_size(s->fifo[i]) > 0)
+ continue;
+ ff_inlink_request_frame(ctx->inputs[i]);
+ return 0;
+ }
+ }
+
+ return FFERROR_NOT_READY;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ AVFilterLink *inlink = ctx->inputs[0];
+ AudioSDRContext *s = ctx->priv;
+
+ s->pts = AV_NOPTS_VALUE;
+
+ s->channels = inlink->channels;
+ outlink->format = inlink->format;
+ outlink->channels = inlink->channels;
+
+ s->fifo[0] = av_audio_fifo_alloc(outlink->format, outlink->channels, 1024);
+ s->fifo[1] = av_audio_fifo_alloc(outlink->format, outlink->channels, 1024);
+ if (!s->fifo[0] || !s->fifo[1])
+ return AVERROR(ENOMEM);
+
+ s->sum_u = av_calloc(outlink->channels, sizeof(*s->sum_u));
+ s->sum_uv = av_calloc(outlink->channels, sizeof(*s->sum_uv));
+ if (!s->sum_u || !s->sum_uv)
+ return AVERROR(ENOMEM);
+
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ AudioSDRContext *s = ctx->priv;
+
+ for (int ch = 0; ch < s->channels; ch++)
+ av_log(ctx, AV_LOG_INFO, "SDR ch%d: %g dB\n", ch, 20. * log10(s->sum_u[ch] / s->sum_uv[ch]));
+
+ av_audio_fifo_free(s->fifo[0]);
+ av_audio_fifo_free(s->fifo[1]);
+
+ av_frame_free(&s->cache[0]);
+ av_frame_free(&s->cache[1]);
+
+ av_freep(&s->sum_u);
+ av_freep(&s->sum_uv);
+}
+
+static const AVFilterPad inputs[] = {
+ {
+ .name = "input0",
+ .type = AVMEDIA_TYPE_AUDIO,
+ },
+ {
+ .name = "input1",
+ .type = AVMEDIA_TYPE_AUDIO,
+ },
+};
+
+static const AVFilterPad outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .config_props = config_output,
+ },
+};
+
+const AVFilter ff_af_asdr = {
+ .name = "asdr",
+ .description = NULL_IF_CONFIG_SMALL("Measure Audio Signal-to-Distortion Ratio."),
+ .priv_size = sizeof(AudioSDRContext),
+ .query_formats = query_formats,
+ .activate = activate,
+ .uninit = uninit,
+ FILTER_INPUTS(inputs),
+ FILTER_OUTPUTS(outputs),
+};
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 73a0bf9c44..7234ca6dbe 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -75,6 +75,7 @@ extern const AVFilter ff_af_arealtime;
extern const AVFilter ff_af_aresample;
extern const AVFilter ff_af_areverse;
extern const AVFilter ff_af_arnndn;
+extern const AVFilter ff_af_asdr;
extern const AVFilter ff_af_asegment;
extern const AVFilter ff_af_aselect;
extern const AVFilter ff_af_asendcmd;
--
2.17.1
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