[FFmpeg-user] filter to "combine" audio tracks (audio mixer)

[Roger Pack]

Hello all.
My basic question is "is there a way to combine audio inputs" (like an
audio mixer) using ffmpeg.
My target would be something like


input1 = -f dshow -audio="something"
input2= -f dshow -audio="something else"
input3= -v dshow -video="something else2"

and then overlay input2 on input2 as the "final" (single) audio track
for the output.

I noticed on
http://wiki.multimedia.cx/index.php?title=Ffmpeg_audio_api
that some previous work apparently has been discussed about an audio API.

Would this be as "easy" as a new libavfilter audio filter that merged
(mixed) the two?  I guess such a one doesn't yet exist, judging by the
list:

http://ffmpeg.org/libavfilter.html#SEC15

Sorry if it's a repeat question just wanted to know if a filter would
be "the best way" or not.
Cheers!
-roger-