[PD] wierd feedback popping with pd/freebob/jack/rt

Rich E reakinator at gmail.com
Thu May 29 04:40:20 CEST 2008

After more testing...

With pd compiled with "JACK_NUM_PORTS 256", audio runs fine at first, but if
the cpu gets a big hit, like when I open a soundfont in [fluid~], the audio
falls behind and I get the pops/clicks again.  If I compile pd with
"JACK_NUM_PORTS 32", this doesn't appear to happen; [fluid~] does its thing,
the gui freezes for a couple seconds, but the audio is fine afterwards.

Hopefully this hints at what the problem really is.


On Wed, May 28, 2008 at 12:37 PM, Rich E <reakinator at gmail.com> wrote:

> IOhannes, thanks for the commit..
> The problem wasn't automatically starting jack. After swapping out lines of
> code from the vanilla version, I discovered the source of bad audio is
> coming from  "#define NUM_JACK_PORTS 1024" .  This seems to be making pd
> fall behind for reasons unknown to me, but if I set it to 256 or below, the
> audio is fine again (I don't know the exact number that is 'over the limit',
> when I switched to 512, I got the pops/clicks).
> One more thing; this only happens with my firewire soundcard (edirol
> FA-101), whereas I don't have the problem with the built-in intel
> soundcard.  So it seems maybe the freebob driver is trying to open all the
> extra ports it doesn't need, thereby making audio fall behind?  I don't know
> if this makes sense, because again, if I open audacity while pd's audio is
> on and popping/clicking, the audio chain is corrected and everything sounds
> fine.  This was my first time looking at jack code and really don't
> understand how it all ties together yet.
>> PS: if you use the sf-tracker for this, please create a bugreport instead
>> of adding to the "patches"
> Sounds good. Should I file a bug report for the above mentioned #define?  I
> would submit a patch, but I don't think just setting the #define to a number
> that works on my computer is good for everyone else.
> regards,
> Rich
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20080528/48ec4495/attachment.htm>

More information about the Pd-list mailing list