avfilter: add aphasemeter filter

1 files changed, 32 insertions, 0 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index 148dce3..e99a308 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -11656,6 +11656,38 @@ tools.
 
 Below is a description of the currently available multimedia filters.
 
+@section aphasemeter
+
+Convert input audio to a video output, displaying the audio phase.
+
+The filter accepts the following options:
+
+@table @option
+@item rate, r
+Set the output frame rate. Default value is @code{25}.
+
+@item size, s
+Set the video size for the output. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+Default value is @code{800x400}.
+
+@item rc
+@item gc
+@item bc
+Specify the red, green, blue contrast. Default values are @code{2},
+@code{7} and @code{1}.
+Allowed range is @code{[0, 255]}.
+
+@item mpc
+Set color which will be used for drawing median phase. If color is
+@code{none} which is default, no median phase value will be drawn.
+@end table
+
+The filter also exports the frame metadata @code{lavfi.aphasemeter.phase} which
+represents mean phase of current audio frame. Value is in range @code{[-1, 1]}.
+The @code{-1} means left and right channels are completely out of phase and
+@code{1} means channels are in phase.
+
 @section avectorscope
 
 Convert input audio to a video output, representing the audio vector