Audio Upmixing?

Der Lockruf des Kaos Der_Lockruf.des-Kaos at
Sat Aug 28 04:07:36 PDT 2004

Hi Dominic,

i read your Mail and have something similar:

I have an AC3 Receiver and a Terratec DMXFire connected over a fiberoptic Cabel.
I use Alsa, JACK, ac3jack and ac3dec to generate a constant AC3 Stream to my Receiver.
(Optional: qjackctl,

With all this installed and correctly configured i can open for example and Divx Movie with mplayer over -ao jack and the Movie with its Stereo Audio is mixed die Left,Right,RearLeft,RearRight and Subwoofer.
This sounds far much better than only Stereo in my Opinion.
I copy the MPlayer Left/Right Stereo to the left/right AC3Jack, than with Help of the LADSPA i make MPlayer Left/Right Stereo a bit louder and direct this to the left/right Rear AC3Jack and i take the MPlayer Left/Right Stereo again with applying
a LowPass Filter and direct it to the Subwoofer Ac3Jack.

And so all Applications that support Jack or Alsa can be mixed together.
Of course you can direct this generated AC3 Stream not only to your AC3 Receiver, but also to a File or something else.
I think every good Sound Editor can grab this Stream from Jack or AC3Jack.

This is the "Nonplusultra" for me, on Windows i only was able to bypass dvd Audio to my Receiver :)
So once again for me, Linux is far more useable, flexible than Windoof (Windows), hm what else would you expect :)
Perhaps it might help you.

Sorry for this lately Answer but as i read your Mail i started again to manage this whole AC3 Thing, this wasn't me first Try to get AC3 running on Linux in such intensive Way, but your Mail motivated me to try it once again and it works now almost perfect.
( One "Bug" is that if i activated my whole AC3 Thing and also start gkrellm, the Sound gets laggy so that i must close gkrellm again, because the xruns are about several Seconds :( )
I now only use AC3 as often as it is possible.
Sadly UT2004 doesn't support Jack :(
So i must deactivate my AC3 if i want to play UT2004 :)

Am Sun, 06 Jun 2004 11:38:07 -0400
schrieb Dominic L Hilsbos <dhilsboslfs at>:

> I would like to find a utility that allows for upmixing from 2 channel 
> stereo to 6 channel surround (ac3, dolby digital).  I thought that 
> perhaps ffmpeg was/would do it, however I replayed the files I got out 
> of it, and they were still just stereo.  Any and all help is appreciated.
> -- 
> Dominic L Hilsbos
> "Peace can not be kept by force.  It can only be achieved through 
> understanding"
> Albert Einstein
> Linux registered user: 283861
> LFS 5.0 ID:12136
> Linux-Mandrake 9.2
> Windows XP
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