I increase audio latency, seems to be only real way to remove clickies

 

 

From: pd-list-bounces@iem.at [mailto:pd-list-bounces@iem.at] On Behalf Of Jean-Marie Adrien
Sent: Wednesday, December 07, 2011 5:52 AM
To: pd-list@iem.at
Subject: [PD] Gem and audio, multiprocessors, Mac

 

Hi list,

 

Is there a strategy to optimize GEM video processing and real time audio on a single Mac using pd~  :

 

Audio in subprocess or in main process ?

Any startup flags ? chmod +s stuff ? shm settings ?

Run two instances of PD with messages between them ?

Subprocess fifo size ?

 

The idea would be to give a priority to sound versus video, if absolutely necessary.

 

Situation :

 

On a single Mac (pro or mini), Gem (pix_video &  tracking, ordinary resolution and fps) and real time audio (10 channels, mainly reading from disk), dispatched on four processor cores via pd~. The sound is generated in the subprocess (big latency 512), the video in the main patch. pd-extended 42.5 osX 10.7 &10.6, gem 93, 92. 

 

Problem :

 

Sound is distorted when Gem is rendering, and becomes immediatly perfect when stopping rendering (destroying the gem window).

Processors seem ok (each core at 75%).

 

 

Sticking with this problem for a couple of months, 

Looked around in archives but didn't find any clear element.

 

 

Thanks

JM