[PlanetCCRMA] FC8, experience so far + pulse audio ...

Fernando Lopez-Lezcano nando at ccrma.Stanford.EDU
Tue May 6 07:51:16 PDT 2008


On Tue, 2008-05-06 at 09:19 -0400, Mike Mazarick wrote:
> I had issues with getting sound to come out from either the newly
> minted linux drivers or from the Via onboard chipset (although the Via
> soundcard seemed to work better, it had more latency).   One of the
> big issues was trying to figure out from the Jack messages, the
> dmesgs, or the scsconfig.log or scsrun.log what the issues were. 

The Jack error and warning messages are not the most friendly ones in
the universe... You should see the ones that the experimental jackmp
prints..., they are even more cryptic :-)

> So far, I’ve de-installed anything related to pulse-audio (because of
> Jack messages, and because it seems to default to 2 audio channels
> running 44.1khz).   I’m also very wary of ‘new’ stuff, and noticed
> that this is supposed to be a replacement for Jack. 

Pulse Audio? No, Pulse Audio is not meant to replace Jack. 

It has a very different goal, which is to provide a unified way in which
desktop applications can share the audio i/o. It has been tried many
times before, but it looks like this time this solution is gathering
momentum. I'm sure some other big project will come up with a newer
brighter idea, and an incompatible one so that we are back to square
one :-P

I _think_ Pulse Audio has/will have a way to connect to Jack, ie: be a
jack client by itself. But I'm not sure. 

On the other hand, Jack was never intended to be an "audio daemon" for
the desktop. It does not have the right stuff for that. So Pulse Audio
or something similar is still needed. 

Pulse Audio can be managed through a control panel and it can be made to
release the audio resources so that other programs (for example Jack)
can use them. 

> I’d just as soon wait until it is known and proven to be better than
> Jack (I just switched from CVS to SVN last month).   I also disabled
> the firewall, because I didn’t want to spend many hours googling
> issues only to discover it is ‘security’ related (I need to get X out
> of the system and on to a PC, for instance).   Fedora is really a beta
> release for RedHat, so, you are always on the ‘bleeding edge’ for a
> few months until the fixes come out.   

It is an it is not (a beta for redhat). It was more so at the beginning
of the Fedora project. Still, it is by no means a "conservative"
distribution :-) It is in the bleeding edge and that has good and bad
vibes associated with it. 

There are many decisions Fedora took that I hate and that affected audio
apps. Sigh. Maybe it is time to start learning debian packaging :-)

> I can understand permissions and ownership, but I don’t necessarily
> understand how you can get something owned by user-root, group-root
> with no world r/w to work unless there is some ACL structure (which I
> don’t want to understand or have to know the details of). 

Well, I don't understand it either. As it worked for me I assumed
nothing had changed. So much for me being up to date. 

... curious ...

Hmmm, looks like the switch to ConsoleKit is related (at least partly)
to fast user switching (ie: having more than one user logged in and
swithing between them "fast" - never tried myself). See:

http://fedoraproject.org/wiki/Desktop/FastUserSwitching

Apparently simple device node permissions access would not be enough in
those situations (from what little I understand). 

I still don't fully understand the mechanism used (it is ACL's, of
course) but well, it seems to be working - apparently not always,
though :-< 

Here's a long thread about it:
https://bugzilla.redhat.com/show_bug.cgi?id=228110
If I had time I'd read it...

Do a:

    getfacl /dev/snd/*

(part of the acl package) to see who _really_ has access to the sound
devices...

> I do believe based on experience that some reasonable percentage of
> the folks trying out sound (and especially Jack) on a FC8 linux daw
> are running into problems and giving up. 

That's too bad but understandable. Anyway, let me know of problems and
if they are within my power to fix I'll try...

[MUNCH]
> The Planet has really done a good job of helping people out over the
> years.    There is usually some type of workaround.   The issue we’re
> currently facing is to explain to a Windows DAW user ( the average
> user of a GL cards) the compelling reasons to switch to Linux.   Have
> PlanetCCRMA available is one of the reasons.

Well, there are many options available now, perhaps Planet CCRMA is no
longer (if it ever was) the best for beginners. 

> PS – one small off topic side note – Dave Marion had found that the
> Gadget Labs cards can be clocked together even if they are in
> different systems. 

Hmmm, that should be true of any card that has an external clock input. 

> This opens up the question of multiple Jacks on multiple systems.   It
> may be that multiple GL cards on multiple systems with sync’d clocks
> may be the least expensive Wave Front Synthesis system when coupled
> with several inexpensive 5.1  sound PC speakers.

Interesting thought... netjack perhaps? (it is included in newer svn 
versions of jack). There is still the issue of frame level synch of 
processes on different machines so that all audio is output at the 
exact same time in all of them, right?

-- Fernando




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