LMMS gives no sound.

JMickle · 08-01-2008, 01:39 PM

Quote:

could not set realtime priority.
ALSA lib pcm_dmix.c:874:(snd_pcm_dmix_open) unable to open slave

I have a feeling that this is the problem.

Sound works fine with other programs, such as Totem for my music, but this doesn't seem to give any sound output at all.

I have just installed it, not changed any settings, and only installed linux today.

I am running the latest version of Ubuntu Desktop.

jax8 · 08-02-2008, 06:21 AM

try

Code:

aoss command

replace command with the application command

matthewg42 · 08-02-2008, 06:50 AM

To expand a little... Linux has had a few sound systems in the kernel over the years. One of the older ones is called OSS. With sound cards which only have one input channel (which is most modern cards), OSS can cause problems by opening the sound card and hogging it.

This can cause the problem you are seeing when another app comes along and wants to use the sound card.

ALSA is another sound system, which can share the sound card between apps.

What you need to do it find the program which is hogging the sound card, and terminate it, then start LMMS.

To find an OSS app which is hogging the sound card:

Code:

sudo lsof |grep /dev/dsp

Typical villains are: older version of flash player or skype, and sound servers like esd.

The aoss solution is a way to make OSS apps play nice with other apps. Say you have a program which uses OSS, like gmfsk. Wheree you would normally launch it using the command:

Code:

gmfsk

change that command to:

Code:

aoss gmfsk

This emulates OSS but does the actual connection to the sound card with the ALSA drivers. It's not 100% reliable, but it usually works.

JMickle · 08-03-2008, 05:37 AM

Thankyou very much, I will try that, although I think I found my problem elsewhere.
You see, I have two sound cards installed at the moment, the on board sound, and a PCI card. I use the PCI card because when I record in Cubase (in winblows) it cuts out practically all the latency, which the on board doesn't.

When I went into the Sound menu in Ubuntu, I switched everything to the on board sound instead of the PCI, and other programs which also didn't work (Amarok, firefox) started working. I just need to try Lmms now, which I haven't had a chance to. If that doesn't work, I will try what you said.

Thanks again, people like you are just another reason why this website is so great

matthewg42 · 08-03-2008, 06:10 AM

I'm sorry to say that I have no experience of multiple soundcards in the same machine. I gather fro listening to people talking about it on podcasts that ALSA gives you the ability to be quite smart about how you use them, but I don't know how to do it.