Re: [LAU] Sharing of Ardour projects

On Mon, May 30, 2011 at 10:28:14AM +0200, Jörn Nettingsmeier wrote:
> On 05/28/2011 01:37 AM, Jörn Nettingsmeier wrote:
>> On 05/27/2011 10:08 PM, Fons Adriaensen wrote:
>
>>> I've got a strange problem with MFV. *Something* is poisoning
>>> the signal graph with Nans or Infs. One visible result is that
>>> e.g. the W channel of one of the jkmeters shows only peaks and
>>> no RMS values (this is to be expected if the filter state gets
>>> a Nan - once a Nan always a Nan). The other indication is that
>>> adding an Ambdec produces a never ending xrun storm even if the
>>> effective CPU load remains below 10%.
>>>
>>> Have you seen anything similar ?
>>
>> not in this session. sc4 can be funny at times, but i haven't had any
>> issues with it for quite a while. i don't have access to the session
>> atm, will ake a look when i return home on sunday. meanwhile, if you
>> want to pinpoint the problem, try muting all channels and then unmute
>> one by one.
>>
>> do the nans crop up immediately, or only after playing some audio?
>
> i just tested the session again, and i don't see any NaNs or INFs. what
> i did notice, though, is that i'm burning a ridiculous amount of cpu for
> this tiny little arrangement - i had tried with 64 frames initially, and
> it maxes out immediately (on an 2.6 ghz i5 quad-core). safe way to run
> it is at -p 1024 -n2.

Turned out to be jconvolver. Added some Nan testing code to zita-convolver
and the problem disappeared, also without the extra code. Could be I
accidentally installed a version compiled on another machine. But then
it's a miracle non of this showed up earlier...

I'm running it on dual qaud-core, period size 256, and CPU load remains
below 10%.

Nice recording BTW. The flugelhorn solo triggered happy memories of
recording the BRTN jazz orchestra - we had an marvellous trumpet /
flugerhorn player then, Bert Joris <http://www.bertjoris.be/>.

Ciao,

-- 
FA
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