[PD] [PD-announce] pd 0.44-0 test 1 released

Roman Haefeli reduzent at gmail.com
Thu Dec 27 23:36:54 CET 2012

On Don, 2012-12-27 at 15:31 -0500, Hans-Christoph Steiner wrote:
> On Dec 27, 2012, at 3:29 PM, Hans-Christoph Steiner wrote:
> > 
> > On Dec 27, 2012, at 2:14 PM, Roman Haefeli wrote:
> > 
> >> On Die, 2012-12-25 at 13:00 -0800, Miller Puckette wrote:
> >>> Hi all -
> >>> I'm afraid to 'fix' this riht now, but will look at it at least.  Alternatively
> >>> I could add a message to pd to restort DSP without stopping/starting the
> >>> audio I/O, which I'm hoping will at least reduce the need to start/stop
> >>> SDP all the time.
> >>> 
> >>> The change that caused this problem is that I fixed Pd not to have the audio
> >>> system open whern DSP isn't running so that, on APIs in which audio is exclusive
> >>> (e.g., ALSA) you can turn DSP off in Pd and go off and use another device
> >>> with Pd remining open.
> >> 
> >> The problem arises when there is one message trying to control many
> >> different tasks:
> >> * switch DSP computing on/off (save CPU time)
> >> * free/occupy the audio back-end (save soundcard time)
> >> * mute/unmute Pd (save ears)
> >> * force recompilation of the DSP graph
> >> 
> >>> An alternative would be to have Pd automatically close audio devices on ALSA,
> >>> OSS, and MMIO but always keep it open when using jack.  But then what about
> >>> portaudio?  I somply don't know the correct way to deal with this.
> >> 
> >> I'd say it's preferable if Pd's behavior is independent from the
> >> back-end currently in use. Rather, I suggest to use different messages
> >> for different tasks. IMHO, 'dsp 0' really should only turn computation
> >> of tilde-objects off as this is what it means and what one expects. What
> >> about a new message to pd 'card 0|1' to free devices which would work
> >> completely independently from 'dsp 0|1'? This would allow to record a
> >> signal to a soundfile without occupying the soundcard, for instance.
> > 
> > I think that having a pulseaudio backend for Pd as the default on GNU/Linux would be the best way to solve this problem.  Pulse will then handle the multiple apps playing at the same time.  Then for people who want to skip Pulse, then can use the ALSA blocking implementation.
> > 
> > An Audio API can be quite different than another, so I don't think it makes sense to treat them all the same in terms of things like whether DSP disconnects the audio API.  For example Mac OS X CoreAudio, even through PortAudio, always has handled multiple apps playing back.  And the "audio stuck" workaround actually only causes problems with CoreAudio.
> Here's a pulseaudio implementation for libpd, I'm sure Patrick would be fine for that code to be included in Pd.
> http://www.workinprogress.ca/libpd/

Pd 0.44 with -pa already supports pulseaudio. -pa is even the default,
so it's only a matter of making <pulse> the default for -pa to get your
desired behavior.


More information about the Pd-list mailing list