[PD-dev] Pd on ARM/Gumstix Overo - audio problems

[Miller Puckette]

Could be a portability problem in Pd's audio I/O code or (more likely
I think) some kind of limitation in the audio driver itself.  Perhaps audio
input only works in one channel and Pd is tring to use it in stereo?  It
migth help to use an external USB audio device if that's practical.

cheers
Miller
On Mon, Mar 05, 2012 at 12:19:04AM +0100, Duncan Speakman wrote:
> Hi all,
> 
> We're running Pd 0.43 on a Gumstix Overo Airstorm with Cortex A8
> architecture, using Linaro 12.02 distribution (which is based on
> Ubuntu 11.10 )
> Pd seems to be working but audio input and output is displaying
> strange behaviours and processing artifacts.
> Simple osc~ objects play their tones at half pitch, and when we run
> audio into it in realtime ( connecting adc~ direct to dac~ ) we
> experience both lower pitch and time granulation. CPU usage reads less
> than 2%.
> 
> Samplerate is 44100 and blocksize is currently at 1024 (anything lower
> than this creates crackling, and causes CPU usage to jump to 80%)
> 
> Does anyone here know if this CPU is just unable to process floating
> point data at the speed required by Pd, or whether there are some
> processing settings/ priority settings or a different kind of kernel
> that would allow Pd to run correctly on this platform.
> We're surprised it's not working as we know PDlib runs fine on the
> iPhone for instance.  We've already successfully run PDa on a Gumstix
> Verdex but really want to move to full Pd to get around the
> limitations of PDa.
> 
> any thoughts or suggestion welcome,
> we're getting desperate!
> 
> duncan
> 
> -- 
> follow me : @ofcircumstance
> 
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