Surround Matrix Encoder - anyone use it?

[wysocki]

There's a plugin supplied in Audacity that is as least as confusing as most others - the Surround Matrix Encoder. It would APPEAR to be used to create a 5.1 surround mp3 I would guess, but there's no docs and it doesn't even ask for any parameters. I went to http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html and there it says it's "untested". Has anyone ever used this and got it to work - or found another way to make 5.1 surround files?

[kozikowski]

<<<It would APPEAR to be used to create a 5.1 surround mp3>>>

My guess would be a Dolby® *.ac3 file. This is normally licensed software similar to Fraunhofer MP3®.

Lame is an open source dodge-ball around the licenses for MP3. I wouldn't be surprised if someone got most of the way through the open source version of a 5.1 encoder.

However, before you fall in love with the idea, there's nothing wimpy about creating an AC3 file. AC3 has dynamic triggers and volume managers. It's designed to simulate the theater experience complete with seat shaking volume changes. It's not just dumping six tracks of normal sound into a tool and turn the crank.

AC3 can also be used on a DVD to save space. Movie DVDs can have both uncompressed PCM music files (the WAV files I like so much) and Dolby AC3. It's a common trick to delete the wasteful PCM sound and encode Dolby as two-channel stereo.

Koz

[steve]

Has anyone ever used this and got it to work

I've tried it, but it does not seem to be compatible with Audacity - not all of the LADSPA plug-ins are.

or found another way to make 5.1 surround files?

In Audacity 1.3.11, go to "Edit menu > Preferences > Import/Export" and select "Use Custom Mix".
Then when you Export a multi-track project you will be given channel mapping options.

Note that Audacity does not yet support multi-channel audio output, so to play the multi-channel file you will need to use another application.