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Linux and multichannel audio

The main things I’ve been struggling with on Ubuntu are surround sound and multichannel audio files. I have a few DVD-A albums in flac format that I like to listen to occasionally. I had a hell of a time getting my Audigy 2 ZS to do surround sound properly; my problem seems to have been driver version conflicts at some level (I compiled my own ALSA drivers). I can now finally watch DVDs with proper surround sound through MPlayer and VLC, though VLC is a little jerky.

Those surround sound files, though, yeesh. I decoded the flac files back to wavs and tried playing them in all sorts of players. The first thing you notice is that they’re in wave extensible format, an MS format, so the channels are mixed up. You can set up a device to have ALSA swap the channels, though you have to have a player that lets you specify the device directly for that to work. Mplayer is such a player and the 6 channel wav file works fairly well. Flac is another story. Playing one results in a horrifically noisy and screechy (that’s the best I can describe it) version, with the music barely recognizable. The ALSA aplay player works for the wav file as well. Of course, those players are not useful players for regular listening. Moving up a little, VLC will play the wav files properly (other than the channel swap, that is). However, when I try to play the flac version, it crashes. Rhythmbox plays the wav file, but I don’t think it supports anything more than stereo. It seems that all the channels are downmixed to stereo automatically. The same is done with the flac version (but it plays!). The player I really want these to work in is AmaroK, my music player of choice. It, however, does the worst. The wav files come out as pure static (annoying, high-pitched static at that). The flac version results in the same playback as MPlayer. I suspect this has something to do with xine, as gxine and Kaffeine do the same thing.

I thought I was out of luck. Then I tried XMMS. Bingo. The flac version works with the channels swapped. A quick change to the ALSA device and I have Deadwing in proper 5.1 audio. I know little about XMMS, but it doesn’t appear to have any library functionality, so I’m a little disappointed. Still, it works.

I’m not sure why it works, exactly. It does use its own flac plugin, so perhaps that’s it. The moral of the story appears to be use MPlayer, VLC, and XMMS. I’m fairly happy.

UPDATE: I’ve recently upgraded to Feisty Fawn and I’ve noticed that Amarok (and xine, by extension) does a better job with those same FLAC files now. They play, sound seems to be sent to the correct channels, but the sound has a pretty annoying warble to it. It’s progress, though.

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