Re: [Rosegarden-user] No audio during playback

[Pedro Lopez-C. <ped...@gm...>]

On Friday, 10 August 2007 05:43, Gus Hartmann wrote:
> I opened up one of the provided .rg files, mozart-quartet.rg, and while
> playing it Qsynth does show activity, but no sound is produced. Alsa is
> correctly configured, and does produce sound under other apps.
>
> 	Any pointers on what I may be doing wrong?

There are several software layers in your setup, and ALSA is only the lowest 
level (driver layer) in the hierarchy.
1.- ALSA (sound driver)
2.- Jack (sound server)
3.- QSynth (synthesizer, MIDI receiver and sound producer)
4.- Rosegarden (MIDI sender)

I would try to isolate the problem in a specific layer. For instance, you 
already tested the sound driver with a sound application, and it worked. 
Next, try to add the Jack sound server, and use some application to verify 
that you can produce sound using the Jack server (xmms has a jack output  
plugin). If the test was successful, run QSynth configured to use Jack, and 
send MIDI events to this program using some programs like aplaymidi (a 
command line MIDI player) and vkeybd (a virtual MIDI keyboard). If all the 
tests were successful, then we know that the problem is in Rosegarden.

> I've been following the instructions in the article at
> http://www.redhat.com/magazine/023sep06/features/rosegarden/ .
> gus gg-gus ~/audio-debug # uname -a
> Linux gg-gus 2.6.20-1.2320.fc5 #1 Tue Jun 12 18:50:38 EDT 2007 i686 i686

I don't use FC5 myself, but this doesn't seem to be the CCRMA optimised   
kernel mentioned in the article. Remember also that QSynth needs a soundfont.

> gus gg-gus ~/audio-debug # qjackctl > qjackctl.output 2>&1 &
> gus gg-gus ~/audio-debug # qsynth > qsynth.output 2>&1 &

Neither qjackctl nor qsynth print any useful message to the standard output. 
Both programs have a "messages" log window instead, where you should search  
for error messages and other clues.

> gus gg-gus ~/audio-debug # cat rosegarden.output
> AlsaDriver - alsa-lib version 1.0.14rc1
> cannot lock down memory for RT thread (Cannot allocate memory)
> cannot use real-time scheduling (FIFO at priority 9) [for thread
> -1210389600, from thread -1210389600] (1: Operation not permitted)

These error messages from Rosegarden mean that you are not running a patched 
version of PAM that has access to realtime scheduling and memory locking for 
all users. This feature is installed from the package "planetccrma-core". It 
is explained here: http://ccrma.stanford.edu/planetccrma/software/node3.html

Regards,
Pedro