Talk:ALSA

Trouble with empty /proc/asound/cardXX
Hi, I hope this is the right spot for this:

I had trouble with ALSA and an empty /proc/asound/card0 directory. Many things never worked because of this (anything that needed card0 right away), especially any configuration in /etc/modprobe.d/alsa.conf that should make another card go to index 0: options snd-hda-intel id=PCH index=0 did not work, as did options snd slots=snd-hda-intel,. I think this was caused by another device taking up slot 0 and then disappearing off the map and not showing up in /proc/asound/cards. After purging everything ALSA related from my kernel and system and adding it again piece by piece, it turned out that the problem were codecs for snd_hda_intel in the kernel. The mysterious card0 was HDMI and disappeared if some other codecs (I do not know exactly which) were compiled. Once I purged them from my kernel, ALSA again honored options set in /etc/modprobe.d/alsa.conf and I could make snd-hda-intel switch to card0. --Jpaul

'Sound mixing inconsistent' is not a good topic
Well, it doesn't make me think of dmix issue. Not that I can think of a better name but it should probably say something about sharing the card between multiple applications, or just something like 'Only one application is able to use the card'. Michał Górny 08:06, 23 August 2012 (UTC)
 * Indeed, the title does not really reflect the issue well. I've renamed the title to Soundcard only available for one application. --SwifT (talk) 18:50, 29 December 2013 (UTC)

Potential merger with Gentoo doc
The alsa guide on the main site will be redirecting to this page. If any content of the guide is needed (reuse), you can find the wikified version in my user space. --SwifT (talk) 07:54, 26 July 2013 (UTC)

JACK and AC3
I am not using AC3, but have been jack running all the time from years. I think the text on jack and ac3 need a complete review, because ac3 is made for listening audio sources like DVD, when jack is mean to produce them before to encode them to AC3 or whatever.

That must imply a jackified player playing an AC3 source, must provide to jack as many audio outputs than audio streams in the AC3 stream. It is up to the user to connect them to another software or to the hardware. I also don't think this will crash jack. If I can find some AC3 source, I can try it. --DominiqueMichel (talk) 16:49, 11 August 2013 (UTC)
 * OK, I find one, and was playing it with mplayer and smplayer. With my audiophile 192, which have only 2 outputs, mplayer play the video but fail to play the sound, as it doesn't find enough outputs. With the built'in hda-intel sound card, mplayer play both the audio and the video. I can even output a 5.1 AC-3 stream as if it was a 7.1 stream. It is just to configure the output as 7.1 in smplayer preferences.--DominiqueMichel (talk) 10:40, 12 August 2013 (UTC)
 * I modified a few more things and removed the note.--DominiqueMichel (talk) 11:21, 12 August 2013 (UTC)

USE=debug
Do we need a warning not to set USE=debug? Following the instructions literally leads to USE=debug set globally then @world being rebuilt. That's a very bad thing for nano users.

What is the standard elsewhere on the wiki for USE=debug? --NeddySeagoon