Arch Linux

mrunion

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From: Jonesborough, TN

Registered: 2007-01-26

Posts: 1,938

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ALSA or OSS?

OK, I'm confused.  I've used Linux off and on for quite a while, but since last October have started making the switch permanently.  I'm currently bitten by the "my HP laptop won't play SYSTEM sounds in gnome/esd" problem.  It DOES play sounds -- MP3s, videos, DVDs, etc.

In my Sound settings in Gnome I have most devices set on "autodetect".  Sound capture is set on "ALSA".

A few days ago I was using "recordmydesktop" to record something and I had the MP3 player running.  When playing back the file I noticed there was no sound recorded.  I played with a few things and never got it recording.  All my channels were unmuted and properly adjusted as to volume, etc.

Now today I downloaded Audacity to play around with.  I couldn't capture sounds the system was playing.  I tried playing a sound and it wouldn't play either.  (Well, it "played" but I heard no sound.)  I checked the settings and when I changed the preferences to use OSS instead of ALSA, it played sound.

I stopped right here becasue aparently I'm confused.  Am I supposed to be using ALSA or OSS?  In the Gnome Sound Preference, I currently have "autodetect" selected for sound playback.  I have to other options:  ALSA and OSS.  Should I specifically select ALSA?  I though OSS was "depricated"?  How come Audacity only works with OSS (/dev/dsp)?

Should I be blacklisting some DAEMON to get OSS to "go away", or should I just be using OSS and make ALSA go away?  I'm so confused.  Help?

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Matt

"It is very difficult to educate the educated."

lloeki

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From: France

Registered: 2007-02-20

Posts: 456

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Re: ALSA or OSS?

both have the same purpose: handle hardware access.
actually, oss really is deprecated, and alsa emulates oss.
esd, along with jack, nas, pulseaudio, arts... are sound servers: they can route audio locally or remotely inside a system, and mix multiple sound streams. gnome system sounds are played via esd (or pulseaudio, which emulates esd, esd being vastly outdated). sound servers rely on alsa or oss for hardware access.

so in the end, you are really only using alsa, with varying layers atop.

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mrunion

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From: Jonesborough, TN

Registered: 2007-01-26

Posts: 1,938

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Re: ALSA or OSS?

OK, I think that makes sense.  Tell me if you know -- how come when I run ESD Audacity only shows me ASLA stuff (three entried) in the "playback" area in preferences.  When I STOP ESD, I get about 8 options -- one being OSS.  Is this normal?  Also, when ESD is running, I get no sound from Audacity.  I have to stop ESD and select OSS to get sound.

Last edited by mrunion (2007-05-14 17:16:49)

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Matt

"It is very difficult to educate the educated."

lloeki

Member

From: France

Registered: 2007-02-20

Posts: 456

Website

Re: ALSA or OSS?

oss gives you a file /dev/dsp and this has to be opened in exclusive mode. therefore it can be opened by only one app at once (sound servers counting as app). audacity then detects that /dev/dsp is in use, and anything depending on it (thus, sound servers) will fail too. and then remains two options, alsa and esd.

in truth, alsa can only open sound device once, just like a file (heh, in unix, everything is a file ), but it has a plugin called dmix allowing to mix multiple sources.

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To know recursion, you must first know recursion.

hacosta

Member

From: Mexico

Registered: 2006-10-22

Posts: 423

Re: ALSA or OSS?

can gnome _not_ use a sound server?  since dmix was enabled by default i just select every application to use alsa and everything works like a charm

mrunion

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From: Jonesborough, TN

Registered: 2007-01-26

Posts: 1,938

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Re: ALSA or OSS?

@hacosta:  I don't know.  I don't know if I understand what you're after.

OK, another question...If I am wanting to record my desktop WITH SOUND using "recordmydesktop", should I investigate oss2jack that is mentioned in the WIKI?  Would that make things possibly work?

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Matt

"It is very difficult to educate the educated."

lloeki

Member

From: France

Registered: 2007-02-20

Posts: 456

Website

Re: ALSA or OSS?

frankly I don't know what recordmydesktop is, so...
oss2jack just emulates oss and routes it into jack, it's like alsa-oss and others ending in dsp (can't recall exaclty, there's one in pulseaudio, maybe 'padsp').

hacosta: no, currently gnome system sounds is the only part requiring a sound server, and that is esd. try to look into pulse, which is very well-designed and lightwieght.
I heard a solution for that is on the way, maybe for gnome 2.20.

Last edited by lloeki (2007-05-14 21:32:02)

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To know recursion, you must first know recursion.

dedhart

Member

Registered: 2006-07-02

Posts: 123

Re: ALSA or OSS?

Do you have alsa-oss installed? if so you should be able to hear sound from both ALSA and OSS applications, though if you have integrated AC97 sound you may want to try running everything through alsa or aoss. It seems to me the more layers you add the more muddled everything becomes. I don't know if you can shut off esd in gnome, if not have you considered a more lightweight desktop like xfce?

mrunion

Member

From: Jonesborough, TN

Registered: 2007-01-26

Posts: 1,938

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Re: ALSA or OSS?

No, I don't have alsa-oss installed.  I thought I read that it's depricated on one of the bug lists (esd locks up gnome -- I have this issue).  As for hearing sound from both OSS and ALSA apps, I can hear that now -- though I have to select OSS for apps like Audacity.  (Maybe that's what you're meaning when you say alsa-oss will handle that.)  Also, I can play a video AND MP3s from different apps at the same time and hear both at the same time.

I tried xfce and really don't like it.  Gnome just feels right.

@lloeki: recordmydesktop is desktop recording software.  You'd use it if you wanted to make a video tutorial for instance.

Maybe I'll reinstall alsa-oss and see if anything changes.  I can always remove it if I don't want it or nothing changes.

Thanks!

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Matt

"It is very difficult to educate the educated."

dmartins

Member

Registered: 2006-09-23

Posts: 360

Re: ALSA or OSS?

Part of your problem may be volume levels on your capture devices. Volumes in linux can be pretty confusing.. on my PC there is (in alsamixer) Front Mic, Mic, and then two input source selectors which can be set to Mic, Front Mic, Line, or CD. THEN, pressing TAB to move to the Capture volume settings there is Capture and Capture 1.

Be aware that gnome's volume settings may not be showing you everything or you might be mis-interpreting what it is showing.. if you aren't seeing a Recording tab you probably should be.

mitsoko

Banned

From: In the Coal Chamber

Registered: 2007-05-08

Posts: 143

Re: ALSA or OSS?

i'd like to jsut point out that if you set your sound system to use esd.
then you most liekly won't be able to play sound in anythign else, as the device is now lockedby esd, the idea here is that if you're going to use a sound server liek esd , you sould use it for all your sound apps.

there is v4 of oss in aur, which seems to work perfectly well at mixing, in my experience it can sometimes lock up temporrily under heavy load, however it works with all apps, providing there are enouh channels configured. i think the max is 16 wich is way more than enough imo, it also solves the issue of no sound in oss apps (many games, et/tce, ts) when an alsa capable app is using in use,

to sum up, i find alsa more stable and efficient, however the oss emulation is teh suckage sometimes so if you depend on apps that on;y support oss, then your most trouble free configuratino is liekly to be using oss v4 ( v3 feels a little .. umm .. clunky? .. to me )