doc/filters: add examples for amix to subsection

doc/filters.texi

@@ -2210,13 +2210,6 @@ and @var{pan} audio filters support many formats). If the @var{amix}
 input has integer samples then @ref{aresample} will be automatically
 inserted to perform the conversion to float samples.
 
-For example
-@example
-ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
-@end example
-will mix 3 input audio streams to a single output with the same duration as the
-first input and a dropout transition time of 3 seconds.
-
 It accepts the following parameters:
 @table @option
 
@@ -2252,6 +2245,26 @@ Beware of heavy clipping if inputs are not normalized prior or after filtering
 by this filter if this option is disabled. By default is enabled.
 @end table
 
+@subsection Examples
+
+@itemize
+
+@item
+This will mix 3 input audio streams to a single output with the same duration as the
+first input and a dropout transition time of 3 seconds:
+@example
+ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
+@end example
+
+@item
+This will mix one vocal and one music input audio stream to a single output with the same duration as the
+longest input. The music will have quarter the weight as the vocals, and the inputs are not normalized:
+@example
+ffmpeg -i VOCALS -i MUSIC -filter_complex amix=inputs=2:duration=longest:dropout_transition=0:weights="1 0.25":normalize=0 OUTPUT
+@end example
+
+@end itemize
+
 @subsection Commands
 
 This filter supports the following commands: