[FFmpeg-cvslog] lavfi/silencedetect: Add mono mode
Nicolas Gaullier
git at videolan.org
Thu Mar 29 17:12:16 EEST 2018
ffmpeg | branch: master | Nicolas Gaullier <nicolas.gaullier at arkena.com> | Mon Feb 19 14:15:30 2018 +0100| [95e47654bce3f76360db2bbd9f34929a3434920a] | committer: Paul B Mahol
lavfi/silencedetect: Add mono mode
In mono mode, silence is detected in any single channel instead of all
of them simultaneously
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=95e47654bce3f76360db2bbd9f34929a3434920a
---
libavfilter/af_silencedetect.c | 78 +++++++++++++++++++++++++++---------------
1 file changed, 51 insertions(+), 27 deletions(-)
diff --git a/libavfilter/af_silencedetect.c b/libavfilter/af_silencedetect.c
index b048d63738..c53b9d9218 100644
--- a/libavfilter/af_silencedetect.c
+++ b/libavfilter/af_silencedetect.c
@@ -36,8 +36,10 @@ typedef struct SilenceDetectContext {
const AVClass *class;
double noise; ///< noise amplitude ratio
double duration; ///< minimum duration of silence until notification
- int64_t nb_null_samples; ///< current number of continuous zero samples
- int64_t start; ///< if silence is detected, this value contains the time of the first zero sample
+ int mono; ///< mono mode : check each channel separately (default = check when ALL channels are silent)
+ int independant_channels; ///< number of entries in following arrays (always 1 in mono mode)
+ int64_t *nb_null_samples; ///< (array) current number of continuous zero samples
+ int64_t *start; ///< (array) 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
void (*silencedetect)(struct SilenceDetectContext *s, AVFrame *insamples,
@@ -52,44 +54,55 @@ static const AVOption silencedetect_options[] = {
{ "noise", "set noise tolerance", OFFSET(noise), AV_OPT_TYPE_DOUBLE, {.dbl=0.001}, 0, DBL_MAX, FLAGS },
{ "d", "set minimum duration in seconds", OFFSET(duration), AV_OPT_TYPE_DOUBLE, {.dbl=2.}, 0, 24*60*60, FLAGS },
{ "duration", "set minimum duration in seconds", OFFSET(duration), AV_OPT_TYPE_DOUBLE, {.dbl=2.}, 0, 24*60*60, FLAGS },
+ { "mono", "check each channel separately", OFFSET(mono), AV_OPT_TYPE_BOOL, {.i64=0.}, 0, 1, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(silencedetect);
-static char *get_metadata_val(AVFrame *insamples, const char *key)
+static void set_meta(AVFrame *insamples, int channel, const char *key, char *value)
{
- AVDictionaryEntry *e = av_dict_get(insamples->metadata, key, NULL, 0);
- return e && e->value ? e->value : NULL;
-}
+ char key2[128];
+ if (channel)
+ snprintf(key2, sizeof(key2), "lavfi.%s.%d", key, channel);
+ else
+ snprintf(key2, sizeof(key2), "lavfi.%s", key);
+ av_dict_set(&insamples->metadata, key2, value, 0);
+}
static av_always_inline void update(SilenceDetectContext *s, AVFrame *insamples,
- int is_silence, int64_t nb_samples_notify,
+ int is_silence, int current_sample, int64_t nb_samples_notify,
AVRational time_base)
{
+ int channel = current_sample % s->independant_channels;
if (is_silence) {
- if (!s->start) {
- s->nb_null_samples++;
- if (s->nb_null_samples >= nb_samples_notify) {
- s->start = insamples->pts - (int64_t)(s->duration / av_q2d(time_base) + .5);
- av_dict_set(&insamples->metadata, "lavfi.silence_start",
- av_ts2timestr(s->start, &time_base), 0);
+ if (!s->start[channel]) {
+ s->nb_null_samples[channel]++;
+ if (s->nb_null_samples[channel] >= nb_samples_notify) {
+ s->start[channel] = insamples->pts - (int64_t)(s->duration / av_q2d(time_base) + .5);
+ set_meta(insamples, s->mono ? channel + 1 : 0, "silence_start",
+ av_ts2timestr(s->start[channel], &time_base));
+ if (s->mono)
+ av_log(s, AV_LOG_INFO, "channel: %d | ", channel);
av_log(s, AV_LOG_INFO, "silence_start: %s\n",
- get_metadata_val(insamples, "lavfi.silence_start"));
+ av_ts2timestr(s->start[channel], &time_base));
}
}
} else {
- if (s->start) {
- av_dict_set(&insamples->metadata, "lavfi.silence_end",
- av_ts2timestr(insamples->pts, &time_base), 0);
- av_dict_set(&insamples->metadata, "lavfi.silence_duration",
- av_ts2timestr(insamples->pts - s->start, &time_base), 0);
- av_log(s, AV_LOG_INFO,
- "silence_end: %s | silence_duration: %s\n",
- get_metadata_val(insamples, "lavfi.silence_end"),
- get_metadata_val(insamples, "lavfi.silence_duration"));
+ if (s->start[channel]) {
+ int64_t end_pts = insamples->pts;
+ int64_t duration_ts = end_pts - s->start[channel];
+ set_meta(insamples, s->mono ? channel + 1 : 0, "silence_end",
+ av_ts2timestr(end_pts, &time_base));
+ set_meta(insamples, s->mono ? channel + 1 : 0, "silence_duration",
+ av_ts2timestr(duration_ts, &time_base));
+ if (s->mono)
+ av_log(s, AV_LOG_INFO, "channel: %d | ", channel);
+ av_log(s, AV_LOG_INFO, "silence_end: %s | silence_duration: %s\n",
+ av_ts2timestr(end_pts, &time_base),
+ av_ts2timestr(duration_ts, &time_base));
}
- s->nb_null_samples = s->start = 0;
+ s->nb_null_samples[channel] = s->start[channel] = 0;
}
}
@@ -103,7 +116,7 @@ static void silencedetect_##name(SilenceDetectContext *s, AVFrame *insamples,
int i; \
\
for (i = 0; i < nb_samples; i++, p++) \
- update(s, insamples, *p < noise && *p > -noise, \
+ update(s, insamples, *p < noise && *p > -noise, i, \
nb_samples_notify, time_base); \
}
@@ -117,6 +130,14 @@ static int config_input(AVFilterLink *inlink)
AVFilterContext *ctx = inlink->dst;
SilenceDetectContext *s = ctx->priv;
+ s->independant_channels = s->mono ? inlink->channels : 1;
+ s->nb_null_samples = av_mallocz_array(sizeof(*s->nb_null_samples), s->independant_channels);
+ if (!s->nb_null_samples)
+ return AVERROR(ENOMEM);
+ s->start = av_mallocz_array(sizeof(*s->start), s->independant_channels);
+ if (!s->start)
+ return AVERROR(ENOMEM);
+
switch (inlink->format) {
case AV_SAMPLE_FMT_DBL: s->silencedetect = silencedetect_dbl; break;
case AV_SAMPLE_FMT_FLT: s->silencedetect = silencedetect_flt; break;
@@ -139,11 +160,14 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
const int nb_channels = inlink->channels;
const int srate = inlink->sample_rate;
const int nb_samples = insamples->nb_samples * nb_channels;
- const int64_t nb_samples_notify = srate * s->duration * nb_channels;
+ const int64_t nb_samples_notify = srate * s->duration * (s->mono ? 1 : nb_channels);
+ int c;
// scale number of null samples to the new sample rate
if (s->last_sample_rate && s->last_sample_rate != srate)
- s->nb_null_samples = srate * s->nb_null_samples / s->last_sample_rate;
+ for (c = 0; c < s->independant_channels; c++) {
+ s->nb_null_samples[c] = srate * s->nb_null_samples[c] / s->last_sample_rate;
+ }
s->last_sample_rate = srate;
// TODO: document metadata
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