From cc5c15595930e473d851b211e4daa4ca3b68e458 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Mon, 22 Apr 2013 12:38:24 +0000 Subject: astats filter Signed-off-by: Paul B Mahol --- doc/filters.texi | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) (limited to 'doc') diff --git a/doc/filters.texi b/doc/filters.texi index 8ce2e2d9fa..eb442f4c2f 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -990,6 +990,51 @@ the data is treated as if all the planes were concatenated. A list of Adler-32 checksums for each data plane. @end table +@section astats + +Display time domain statistical information about the audio channels. +Statistics are calculated and displayed for each audio channel and, +where applicable, an overall figure is also given. + +The filter accepts the following option: +@table @option +@item length +Short window length in seconds, used for peak and trough RMS measurement. +Default is @code{0.05} (50 miliseconds). Allowed range is @code{[0.1 - 10]}. +@end table + +A description of each shown parameter follows: + +@table @option +@item DC offset +Mean amplitude displacement from zero. + +@item Min level +Minimal sample level. + +@item Max level +Maximal sample level. + +@item Peak level dB +@item RMS level dB +Standard peak and RMS level measured in dBFS. + +@item RMS peak dB +@item RMS trough dB +Peak and trough values for RMS level measured over a short window. + +@item Crest factor +Standard ratio of peak to RMS level (note: not in dB). + +@item Flat factor +Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels +(i.e. either @var{Min level} or @var{Max level}). + +@item Peak count +Number of occasions (not the number of samples) that the signal attained either +@var{Min level} or @var{Max level}. +@end table + @section astreamsync Forward two audio streams and control the order the buffers are forwarded. -- cgit v1.2.3