From 0c01947316eaaa46946f9e93218fe5ab115df905 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20B=C5=93sch?= Date: Tue, 3 Jan 2012 23:47:09 +0100 Subject: [PATCH] lavfi: add audio silencedetect filter. --- Changelog | 1 + doc/filters.texi | 30 ++++++ libavfilter/Makefile | 1 + libavfilter/af_silencedetect.c | 175 +++++++++++++++++++++++++++++++++ libavfilter/allfilters.c | 1 + libavfilter/avfilter.h | 4 +- 6 files changed, 210 insertions(+), 2 deletions(-) create mode 100644 libavfilter/af_silencedetect.c diff --git a/Changelog b/Changelog index 13736b0c71..a32a4eb040 100644 --- a/Changelog +++ b/Changelog @@ -20,6 +20,7 @@ version next: - v308 Quicktime Uncompressed 4:4:4 encoder and decoder - yuv4 libquicktime packed 4:2:0 encoder and decoder - ffprobe -show_frames option +- silencedetect audio filter version 0.9: diff --git a/doc/filters.texi b/doc/filters.texi index eaa2c33851..d0075f2453 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -358,6 +358,36 @@ Note that @command{ffmpeg} integrates a default down-mix (and up-mix) system that should be preferred (see "-ac" option) unless you have very specific needs. +@section silencedetect + +Detect silence in an audio stream. + +This filter logs a message when it detects that the input audio volume is less +or equal to a noise tolerance value for a duration greater or equal to the +minimum detected noise duration. + +The printed times and duration are expressed in seconds. + +@table @option +@item duration, d +Set silence duration until notification (default is 2 seconds). + +@item noise, n +Set noise tolerance. Can be specified in dB (in case "dB" is appended to the +specified value) or amplitude ratio. Default is -60dB, or 0.001. +@end table + +Detect 5 seconds of silence with -50dB noise tolerance: +@example +silencedetect=n=-50dB:d=5 +@end example + +Complete example with @command{ffmpeg} to detect silence with 0.0001 noise +tolerance in @file{silence.mp3}: +@example +ffmpeg -f lavfi -i amovie=silence.mp3,silencedetect=noise=0.0001 -f null - +@end example + @section volume Adjust the input audio volume. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index 0d8f120f1a..d4b71d27c0 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -34,6 +34,7 @@ OBJS-$(CONFIG_ASPLIT_FILTER) += af_asplit.o OBJS-$(CONFIG_ASTREAMSYNC_FILTER) += af_astreamsync.o OBJS-$(CONFIG_EARWAX_FILTER) += af_earwax.o OBJS-$(CONFIG_PAN_FILTER) += af_pan.o +OBJS-$(CONFIG_SILENCEDETECT_FILTER) += af_silencedetect.o OBJS-$(CONFIG_VOLUME_FILTER) += af_volume.o OBJS-$(CONFIG_ABUFFER_FILTER) += asrc_abuffer.o diff --git a/libavfilter/af_silencedetect.c b/libavfilter/af_silencedetect.c new file mode 100644 index 0000000000..73521b02be --- /dev/null +++ b/libavfilter/af_silencedetect.c @@ -0,0 +1,175 @@ +/* + * Copyright (c) 2012 Clément Bœsch + * + * 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 + */ + +/** + * @file + * Audio silence detector + */ + +#include "libavutil/opt.h" +#include "avfilter.h" + +typedef struct { + const AVClass *class; + char *noise_str; ///< noise option string + double noise; ///< noise amplitude ratio + int duration; ///< minimum duration of silence until notification + int64_t nb_null_samples; ///< current number of continuous zero samples + double start; ///< if silence is detected, this value contains the time of the first zero sample + int last_sample_rate; ///< last sample rate to check for sample rate changes +} SilenceDetectContext; + +#define OFFSET(x) offsetof(SilenceDetectContext, x) +static const AVOption silencedetect_options[] = { + { "n", "set noise tolerance", OFFSET(noise_str), AV_OPT_TYPE_STRING, {.str="-60dB"}, CHAR_MIN, CHAR_MAX }, + { "noise", "set noise tolerance", OFFSET(noise_str), AV_OPT_TYPE_STRING, {.str="-60dB"}, CHAR_MIN, CHAR_MAX }, + { "d", "set minimum duration in seconds", OFFSET(duration), AV_OPT_TYPE_INT, {.dbl=2}, 0, INT_MAX}, + { "duration", "set minimum duration in seconds", OFFSET(duration), AV_OPT_TYPE_INT, {.dbl=2}, 0, INT_MAX}, + { NULL }, +}; + +static const char *silencedetect_get_name(void *ctx) +{ + return "silencedetect"; +} + +static const AVClass silencedetect_class = { + .class_name = "SilenceDetectContext", + .item_name = silencedetect_get_name, + .option = silencedetect_options, +}; + +static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) +{ + int ret; + char *tail; + SilenceDetectContext *silence = ctx->priv; + + silence->class = &silencedetect_class; + av_opt_set_defaults(silence); + + if ((ret = av_set_options_string(silence, args, "=", ":")) < 0) { + av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args); + return ret; + } + + silence->noise = strtod(silence->noise_str, &tail); + if (!strcmp(tail, "dB")) { + silence->noise = pow(10, silence->noise/20); + } else if (*tail) { + av_log(ctx, AV_LOG_ERROR, "Invalid value '%s' for noise parameter.\n", + silence->noise_str); + return AVERROR(EINVAL); + } + + return 0; +} + +static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples) +{ + int i; + SilenceDetectContext *silence = inlink->dst->priv; + const int nb_channels = av_get_channel_layout_nb_channels(inlink->channel_layout); + const int srate = inlink->sample_rate; + const int nb_samples = insamples->audio->nb_samples * nb_channels; + const int64_t nb_samples_notify = srate * silence->duration * nb_channels; + + // scale number of null samples to the new sample rate + if (silence->last_sample_rate && silence->last_sample_rate != srate) + silence->nb_null_samples = + srate * silence->nb_null_samples / silence->last_sample_rate; + silence->last_sample_rate = srate; + + // TODO: support more sample formats + if (insamples->format == AV_SAMPLE_FMT_DBL) { + double *p = (double *)insamples->data[0]; + + for (i = 0; i < nb_samples; i++, p++) { + if (*p < silence->noise && *p > -silence->noise) { + if (!silence->start) { + silence->nb_null_samples++; + if (silence->nb_null_samples >= nb_samples_notify) { + silence->start = insamples->pts * av_q2d(inlink->time_base) - silence->duration; + av_log(silence, AV_LOG_INFO, + "silence_start: %f\n", silence->start); + } + } + } else { + if (silence->start) { + double end = insamples->pts * av_q2d(inlink->time_base); + av_log(silence, AV_LOG_INFO, + "silence_end: %f | silence_duration: %f\n", + end, end - silence->start); + } + silence->nb_null_samples = silence->start = 0; + } + } + } + + avfilter_filter_samples(inlink->dst->outputs[0], insamples); +} + +static int query_formats(AVFilterContext *ctx) +{ + AVFilterFormats *formats = NULL; + enum AVSampleFormat sample_fmts[] = { + AV_SAMPLE_FMT_DBL, + AV_SAMPLE_FMT_NONE + }; + int packing_fmts[] = { AVFILTER_PACKED, -1 }; + + formats = avfilter_make_all_channel_layouts(); + if (!formats) + return AVERROR(ENOMEM); + avfilter_set_common_channel_layouts(ctx, formats); + + formats = avfilter_make_format_list(sample_fmts); + if (!formats) + return AVERROR(ENOMEM); + avfilter_set_common_sample_formats(ctx, formats); + + formats = avfilter_make_format_list(packing_fmts); + if (!formats) + return AVERROR(ENOMEM); + avfilter_set_common_packing_formats(ctx, formats); + + return 0; +} + +AVFilter avfilter_af_silencedetect = { + .name = "silencedetect", + .description = NULL_IF_CONFIG_SMALL("Detect silence."), + .priv_size = sizeof(SilenceDetectContext), + .init = init, + .query_formats = query_formats, + + .inputs = (const AVFilterPad[]) { + { .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .get_audio_buffer = avfilter_null_get_audio_buffer, + .filter_samples = filter_samples, }, + { .name = NULL } + }, + .outputs = (const AVFilterPad[]) { + { .name = "default", + .type = AVMEDIA_TYPE_AUDIO, }, + { .name = NULL } + }, +}; diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 621568e60c..8286d4d21b 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -44,6 +44,7 @@ void avfilter_register_all(void) REGISTER_FILTER (ASTREAMSYNC, astreamsync, af); REGISTER_FILTER (EARWAX, earwax, af); REGISTER_FILTER (PAN, pan, af); + REGISTER_FILTER (SILENCEDETECT, silencedetect, af); REGISTER_FILTER (VOLUME, volume, af); REGISTER_FILTER (ABUFFER, abuffer, asrc); diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h index d88d3aba02..9c795978aa 100644 --- a/libavfilter/avfilter.h +++ b/libavfilter/avfilter.h @@ -30,8 +30,8 @@ #include "libavcodec/avcodec.h" #define LIBAVFILTER_VERSION_MAJOR 2 -#define LIBAVFILTER_VERSION_MINOR 57 -#define LIBAVFILTER_VERSION_MICRO 101 +#define LIBAVFILTER_VERSION_MINOR 58 +#define LIBAVFILTER_VERSION_MICRO 100 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ LIBAVFILTER_VERSION_MINOR, \