[PD] [PD-ot] How to massage pd into starting with Alsa on Beagleboard
Claude Heiland-Allen
claudiusmaximus at goto10.org
Fri Jul 16 13:45:10 CEST 2010
Hi,
This should be on pd-list not pd-ot - Pd usage is off-topic on this
pd-offtopic list ;) - but replying here too in case you're not on the
other one (with pd-list as CC: and reply-to:).
Also see this possibly-related thread, which I haven't checked in
detail, so my reply below may be misinformation:
http://thread.gmane.org/gmane.comp.multimedia.puredata.general/69002
http://thread.gmane.org/gmane.comp.multimedia.puredata.general/69044
http://thread.gmane.org/gmane.comp.multimedia.puredata.general/69045
On 16/07/10 11:15, Edgar Berdahl wrote:
> Furthermore, I can start up a jack audio server as long as I disable the
> audio inputs using -P
> # /usr/bin/jackd -d alsa -d hw:0 -r 44100 -P -p 64
Does "mplayer -ao jack" work?
> However, for the life of me I cannot seem to get Pd to produce sound
> output. For instance, if I try to start Pd using jack
> # pd -jack -noadc test.pd &
> it resets the number of channels to zero, and the CPU usage according to
> top skyrockets to about 95%. To try to start audio, I have to choose
> Media|jack, manually put a check in the box "output device 1", and set
> the channels to 2. Then Pd starts to report, "audio I/O stuck... closing
> audio".
Specifying the number of channels is necessary with -jack with some
(buggy) Pd versions. I use "pd -jack -channels 2", you don't need
"-noadc" because you might want to connect some other jack app (eg
mplayer) to Pd.
See if "pd -jack -channels 2" with [adc~]==[dac~] in a patch passes
through "mplayer -ao jack" without any problems, is what I would try.
> It doesn't matter whether I am using "omap3beagle (hardware)" or
> "omap3beagle (plug-in)".
I have to use "plug-in" for my USB soundcard in 24bit mode, as Pd
doesn't seem to support that sample format natively.
> Does anyone have any other ideas for ways in which I might be able to
> get Pd to produce sound out like mplayer does? I have tried all the
> startup switch combos that immediately came to mind. Could there be some
> inherent reason why Pd will not work if zero audio input channels are
> available?
If Pd is pegging the CPU, maybe something is wrong. Does the
beagleboard have a floating point unit (FPU)? If not, it would
definitely be better to try an integer-dsp version of Pd (such as
pda/pd-anywhere/pd-mobile/whatever it's called these days).
Good luck,
Claude
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