It accepts the following parameters:
@table @option
-@item channel_layout
-The channel layout of the output stream.
-
@item map
Map channels from input to output. The argument is a '|'-separated list of
mappings, each in the @code{@var{in_channel}-@var{out_channel}} or
@var{out_channel} is the name of the output channel or its index in the output
channel layout. If @var{out_channel} is not given then it is implicitly an
index, starting with zero and increasing by one for each mapping.
+
+@item channel_layout
+The channel layout of the output stream.
@end table
If no mapping is present, the filter will implicitly map input channels to