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Since I upgraded to Ubuntu Hardy, I´ve had nothing but heartache when trying to play DVDs with VLC. Specifically, no matter what Audio Settings were used, there was no sound during playback. I am aware that Hardy has a new default sound server, Pulse Audio, and that there have been a fair number of issues. In fact, I myself had to make a change to the default sound settings, under System > Preferences > Sound. In order to enable system sound, I had to change everything from Automatic to ALSA.

I found all sorts of solutions, but none of them worked for me. One person said his problem was resolved by installing vlc-plugin-alsa while setting the ´Output Modules´ setting (visible by enabling ´Advanced Settings´) to ALSA. Given my previous issue, mentioned above, I thought this would be my fix, but again, no joy.

Then, I ran across a blog post in which the author aired his gripes with PulseAudio. Deep in the comments, a Pulse Audio developer explains the root of the problem; while doing so, he mentions a workaround: ´libflashsupport´. That was my fix! As it turns out, Ubuntu has the fix available via a package. It appears that the VLC dependencies haven´t been updated to include it.

As far as the problem was concerned, it never occurred to me that whenever I tried to run VLC, I´d also had Firefox open, which, due to issues with Flash 9, allowed YouTube or some other flash-dependent website to block access to my soundcard. Grrrr.

Since, he explained it a hell of alot better than I ever could, I´ll quote him directly:

This error is basically pulse saying it cannot open the front:0 device as it is in use by another application (e.g. something else has claimed exclusive access to the h/w). Pulse may indeed grab the audio hardware but alsa should be configured to route the “default” device via pulse and everything works as expected with all apps having access to audio “hardware”.

Pulse is not able to “lock your audio to the firefox stream” but if Firefox is eating all the streams, then this is probably an issue with an old version of Flash plugin which used the ALSA API totally incorrectly (opening as many connections as possible!). This has been fixed in newer flash plugins but the pulseaudio community also worked around this bug (in a closed source app!) via the libflashsupport plugin API. So the community has done everything they can to ensure this isn’t a problem.

Anyway, long story short, if you´re running Ubuntu 8.04 (Hardy Heron) and having an issue with sound in VLC, close Firefox and try again. If you then get sound, you need to install the package ´libflashsupport´.

apt-get install libflashsupport

This entry was posted on Tuesday, August 26th, 2008 at 10:46 pm and is filed under tech. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.