[FFmpeg-cvslog] avfilter/af_silenceremove: add peak detector
Paul B Mahol
git at videolan.org
Sun Dec 27 20:51:43 CET 2015
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sun Dec 27 20:45:46 2015 +0100| [1809894b2afdfb84dc97ac8b589c00bdb04b0ab7] | committer: Paul B Mahol
avfilter/af_silenceremove: add peak detector
Signed-off-by: Paul B Mahol <onemda at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1809894b2afdfb84dc97ac8b589c00bdb04b0ab7
---
doc/filters.texi | 4 ++
libavfilter/af_silenceremove.c | 106 +++++++++++++++++++++++++++-------------
2 files changed, 77 insertions(+), 33 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 491b141..abec3c3 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2969,6 +2969,10 @@ at the beginning of each period of silence.
For example, if you want to remove long pauses between words but do not want
to remove the pauses completely. Default value is @code{0}.
+ at item detection
+Set how is silence detected. Can be @code{rms} or @code{peak}. Second is faster
+and works better with digital silence which is exactly 0.
+Default value is @code{rms}.
@end table
@subsection Examples
diff --git a/libavfilter/af_silenceremove.c b/libavfilter/af_silenceremove.c
index 3389d64..c547901 100644
--- a/libavfilter/af_silenceremove.c
+++ b/libavfilter/af_silenceremove.c
@@ -65,11 +65,15 @@ typedef struct SilenceRemoveContext {
double *window_current;
double *window_end;
int window_size;
- double rms_sum;
+ double sum;
int leave_silence;
int restart;
int64_t next_pts;
+
+ int detection;
+ void (*update)(struct SilenceRemoveContext *s, double sample);
+ double(*compute)(struct SilenceRemoveContext *s, double sample);
} SilenceRemoveContext;
#define OFFSET(x) offsetof(SilenceRemoveContext, x)
@@ -82,11 +86,58 @@ static const AVOption silenceremove_options[] = {
{ "stop_duration", NULL, OFFSET(stop_duration), AV_OPT_TYPE_DURATION, {.i64=0}, 0, 9000, FLAGS },
{ "stop_threshold", NULL, OFFSET(stop_threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, DBL_MAX, FLAGS },
{ "leave_silence", NULL, OFFSET(leave_silence), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
+ { "detection", NULL, OFFSET(detection), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS, "detection" },
+ { "peak", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "detection" },
+ { "rms", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "detection" },
{ NULL }
};
AVFILTER_DEFINE_CLASS(silenceremove);
+static double compute_peak(SilenceRemoveContext *s, double sample)
+{
+ double new_sum;
+
+ new_sum = s->sum;
+ new_sum -= *s->window_current;
+ new_sum += fabs(sample);
+
+ return new_sum / s->window_size;
+}
+
+static void update_peak(SilenceRemoveContext *s, double sample)
+{
+ s->sum -= *s->window_current;
+ *s->window_current = fabs(sample);
+ s->sum += *s->window_current;
+
+ s->window_current++;
+ if (s->window_current >= s->window_end)
+ s->window_current = s->window;
+}
+
+static double compute_rms(SilenceRemoveContext *s, double sample)
+{
+ double new_sum;
+
+ new_sum = s->sum;
+ new_sum -= *s->window_current;
+ new_sum += sample * sample;
+
+ return sqrt(new_sum / s->window_size);
+}
+
+static void update_rms(SilenceRemoveContext *s, double sample)
+{
+ s->sum -= *s->window_current;
+ *s->window_current = sample * sample;
+ s->sum += *s->window_current;
+
+ s->window_current++;
+ if (s->window_current >= s->window_end)
+ s->window_current = s->window;
+}
+
static av_cold int init(AVFilterContext *ctx)
{
SilenceRemoveContext *s = ctx->priv;
@@ -96,16 +147,27 @@ static av_cold int init(AVFilterContext *ctx)
s->restart = 1;
}
+ switch (s->detection) {
+ case 0:
+ s->update = update_peak;
+ s->compute = compute_peak;
+ break;
+ case 1:
+ s->update = update_rms;
+ s->compute = compute_rms;
+ break;
+ };
+
return 0;
}
-static void clear_rms(SilenceRemoveContext *s)
+static void clear_window(SilenceRemoveContext *s)
{
memset(s->window, 0, s->window_size * sizeof(*s->window));
s->window_current = s->window;
s->window_end = s->window + s->window_size;
- s->rms_sum = 0;
+ s->sum = 0;
}
static int config_input(AVFilterLink *inlink)
@@ -118,7 +180,7 @@ static int config_input(AVFilterLink *inlink)
if (!s->window)
return AVERROR(ENOMEM);
- clear_rms(s);
+ clear_window(s);
s->start_duration = av_rescale(s->start_duration, inlink->sample_rate,
AV_TIME_BASE);
@@ -153,28 +215,6 @@ static int config_input(AVFilterLink *inlink)
return 0;
}
-static double compute_rms(SilenceRemoveContext *s, double sample)
-{
- double new_sum;
-
- new_sum = s->rms_sum;
- new_sum -= *s->window_current;
- new_sum += sample * sample;
-
- return sqrt(new_sum / s->window_size);
-}
-
-static void update_rms(SilenceRemoveContext *s, double sample)
-{
- s->rms_sum -= *s->window_current;
- *s->window_current = sample * sample;
- s->rms_sum += *s->window_current;
-
- s->window_current++;
- if (s->window_current >= s->window_end)
- s->window_current = s->window;
-}
-
static void flush(AVFrame *out, AVFilterLink *outlink,
int *nb_samples_written, int *ret)
{
@@ -209,12 +249,12 @@ silence_trim:
for (i = 0; i < nbs; i++) {
threshold = 0;
for (j = 0; j < inlink->channels; j++) {
- threshold |= compute_rms(s, ibuf[j]) > s->start_threshold;
+ threshold |= s->compute(s, ibuf[j]) > s->start_threshold;
}
if (threshold) {
for (j = 0; j < inlink->channels; j++) {
- update_rms(s, *ibuf);
+ s->update(s, *ibuf);
s->start_holdoff[s->start_holdoff_end++] = *ibuf++;
nb_samples_read++;
}
@@ -232,7 +272,7 @@ silence_trim:
s->start_holdoff_end = 0;
for (j = 0; j < inlink->channels; j++)
- update_rms(s, ibuf[j]);
+ s->update(s, ibuf[j]);
ibuf += inlink->channels;
nb_samples_read += inlink->channels;
@@ -284,7 +324,7 @@ silence_copy:
for (i = 0; i < nbs; i++) {
threshold = 1;
for (j = 0; j < inlink->channels; j++)
- threshold &= compute_rms(s, ibuf[j]) > s->stop_threshold;
+ threshold &= s->compute(s, ibuf[j]) > s->stop_threshold;
if (threshold && s->stop_holdoff_end && !s->leave_silence) {
s->mode = SILENCE_COPY_FLUSH;
@@ -292,14 +332,14 @@ silence_copy:
goto silence_copy_flush;
} else if (threshold) {
for (j = 0; j < inlink->channels; j++) {
- update_rms(s, *ibuf);
+ s->update(s, *ibuf);
*obuf++ = *ibuf++;
nb_samples_read++;
nb_samples_written++;
}
} else if (!threshold) {
for (j = 0; j < inlink->channels; j++) {
- update_rms(s, *ibuf);
+ s->update(s, *ibuf);
if (s->leave_silence) {
*obuf++ = *ibuf;
nb_samples_written++;
@@ -323,7 +363,7 @@ silence_copy:
s->start_found_periods = 0;
s->start_holdoff_offset = 0;
s->start_holdoff_end = 0;
- clear_rms(s);
+ clear_window(s);
s->mode = SILENCE_TRIM;
flush(out, outlink, &nb_samples_written, &ret);
goto silence_trim;
More information about the ffmpeg-cvslog
mailing list