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| author | Paul B Mahol <onemda@gmail.com> | 2023-05-28 17:37:55 +0200 |
|---|---|---|
| committer | Paul B Mahol <onemda@gmail.com> | 2023-05-29 11:47:10 +0200 |
| commit | f02964aee1ed06ac4a67103904d5fae2862fa45e (patch) | |
| tree | 9b8287adb5aa73acdaec4fadee3b1b618292c728 | |
| parent | aa4acc111e6ea1117dfec230435fdb26ec7631d9 (diff) | |
| download | ffmpeg-f02964aee1ed06ac4a67103904d5fae2862fa45e.tar.gz | |
avfilter/af_silenceremove: add standard deviation detector
Useful in cases audio samples DC offset is not ~0.0, where
other detectors will fail to detect silence.
| -rw-r--r-- | doc/filters.texi | 2 | ||||
| -rw-r--r-- | libavfilter/af_silenceremove.c | 9 | ||||
| -rw-r--r-- | libavfilter/silenceremove_template.c | 17 |
3 files changed, 28 insertions, 0 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 2333cfaf7a..c47e88e5d4 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -6474,6 +6474,8 @@ Maximum of absolute values of samples in moving window. Median of absolute values of samples in moving window. @item ptp Absolute of max peak to min peak difference of samples in moving window. +@item dev +Standard deviation of values of samples in moving window. @end table Default value is @code{rms}. diff --git a/libavfilter/af_silenceremove.c b/libavfilter/af_silenceremove.c index c7975a9365..4cb662080b 100644 --- a/libavfilter/af_silenceremove.c +++ b/libavfilter/af_silenceremove.c @@ -38,6 +38,7 @@ enum SilenceDetect { D_PEAK, D_MEDIAN, D_PTP, + D_DEV, D_NB }; @@ -146,6 +147,7 @@ static const AVOption silenceremove_options[] = { { "peak", "use max absolute values of samples", 0, AV_OPT_TYPE_CONST, {.i64=D_PEAK},0, 0, AF, "detection" }, { "median", "use median of absolute values of samples", 0, AV_OPT_TYPE_CONST, {.i64=D_MEDIAN},0, 0, AF, "detection" }, { "ptp", "use absolute of max peak to min peak difference", 0, AV_OPT_TYPE_CONST, {.i64=D_PTP}, 0, 0, AF, "detection" }, + { "dev", "use standard deviation from values of samples", 0, AV_OPT_TYPE_CONST, {.i64=D_DEV}, 0, 0, AF, "detection" }, { "window", "set duration of window for silence detection", OFFSET(window_duration_opt), AV_OPT_TYPE_DURATION, {.i64=20000}, 0, 100000000, AF }, { "timestamp", "set how every output frame timestamp is processed", OFFSET(timestamp_mode), AV_OPT_TYPE_INT, {.i64=TS_WRITE}, 0, TS_NB-1, AF, "timestamp" }, { "write", "full timestamps rewrite, keep only the start time", 0, AV_OPT_TYPE_CONST, {.i64=TS_WRITE}, 0, 0, AF, "timestamp" }, @@ -230,6 +232,9 @@ static int config_output(AVFilterLink *outlink) case D_RMS: s->cache_size = 1; break; + case D_DEV: + s->cache_size = 2; + break; case D_MEDIAN: case D_PEAK: case D_PTP: @@ -263,6 +268,10 @@ static int config_output(AVFilterLink *outlink) s->compute_flt = compute_avg_flt; s->compute_dbl = compute_avg_dbl; break; + case D_DEV: + s->compute_flt = compute_dev_flt; + s->compute_dbl = compute_dev_dbl; + break; case D_PTP: s->compute_flt = compute_ptp_flt; s->compute_dbl = compute_ptp_dbl; diff --git a/libavfilter/silenceremove_template.c b/libavfilter/silenceremove_template.c index 8536d5e723..009ed52f89 100644 --- a/libavfilter/silenceremove_template.c +++ b/libavfilter/silenceremove_template.c @@ -307,6 +307,23 @@ static ftype fn(compute_rms)(ftype *cache, ftype sample, ftype wsample, return SQRT(r / window_size); } +static ftype fn(compute_dev)(ftype *ss, ftype x, ftype px, + int n, int *unused, int *unused2) +{ + ftype r; + + ss[0] += x; + ss[0] -= px; + + ss[1] += x * x; + ss[1] -= px * px; + ss[1] = FMAX(ss[1], ZERO); + + r = FMAX(ss[1] - ss[0] * ss[0] / n, ZERO) / n; + + return SQRT(r); +} + static void fn(filter_start)(AVFilterContext *ctx, const ftype *src, ftype *dst, int *nb_out_samples, |