avfilter: add aexciter audio filter

1 files changed, 56 insertions, 0 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index dc42927f6a..85052aa18d 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -1003,6 +1003,62 @@ aeval=val(0)|-val(1)
 @end example
 @end itemize
 
+@section aexciter
+
+An exciter is used to produce high sound that is not present in the
+original signal. This is done by creating harmonic distortions of the
+signal which are restricted in range and added to the original signal.
+An Exciter raises the upper end of an audio signal without simply raising
+the higher frequencies like an equalizer would do to create a more
+"crisp" or "brilliant" sound.
+
+The filter accepts the following options:
+
+@table @option
+@item level_in
+Set input level prior processing of signal.
+Allowed range is from 0 to 64.
+Default value is 1.
+
+@item level_out
+Set output level after processing of signal.
+Allowed range is from 0 to 64.
+Default value is 1.
+
+@item amount
+Set the amount of harmonics added to original signal.
+Allowed range is from 0 to 64.
+Default value is 1.
+
+@item drive
+Set the amount of newly created harmonics.
+Allowed range is from 0.1 to 10.
+Default value is 8.5.
+
+@item blend
+Set the octave of newly created harmonics.
+Allowed range is from -10 to 10.
+Default value is 0.
+
+@item freq
+Set the lower frequency limit of producing harmonics in Hz.
+Allowed range is from 2000 to 12000 Hz.
+Default is 7500 Hz.
+
+@item ceil
+Set the upper frequency limit of producing harmonics.
+Allowed range is from 9999 to 20000 Hz.
+If value is lower than 10000 Hz no limit is applied.
+
+@item listen
+Mute the original signal and output only added harmonics.
+By default is disabled.
+@end table
+
+@subsection Commands
+
+This filter supports the all above options as @ref{commands}.
+
 @anchor{afade}
 @section afade