[PD-ot] Record PCM output - ALSA - Rapsberry Pi

[Pierre Massat]

Hi,

Yes, recording to mono would be a good idea.
I don't know to what extend the quality would suffer from a sample rate
reduction though. I've read that it would only cut higher frequencies.
Another problem is that I'm not sure i'll be able to read these file (say
at 22050) in a Pd patch (at 44100).

What you're saying about CPU load and RAM makes sense, but i'd like to try
anyway, just to know whether it'd work or not. Somebody on the RPi forum
suggested that I use Pulseaudio. I don't even know if Pd works with Pulse.
Anyways...

Thank you for your reply.

Cheers,

Pierre.

2012/11/25 Greg Schroeder <gmschroeder at gmail.com>

> You could write a patch that records 16-bit mono .wav, at as low a
> sample rate as you'd like, to .wav with writesf~ . . . more or less
> copy-pasting from the help page.
> Recording to something besides .wav, especially into a separate
> application (which just because it's a separate application will need
> more processing power) in realtime, needs encoding (and thus
> processing power and RAM) as you write, which is going to be a bigger
> problem than disk space on a raspberry pi, I'd think.
> How long are you planning to record, and what is your file size limitation?
>
> Someone correct me if I'm wrong, for my information as much as his,
> Greg
>
> On Sun, Nov 25, 2012 at 2:48 PM, Pierre Massat <pimassat at gmail.com> wrote:
> > Hi Hans,
> >
> > Thanks for your reply. I can't use writesf~ alone because i want to save
> > some disk space, wav is too big.
> > Is there a way i can run Pd, and then pipe its output to another program
> to
> > record it whenever I want? I don't want Pd to continuously write to a
> file
> > because i'm running it for hours.
> >
> > Cheers,
> >
> > Pierre.
> >
> >
> > 2012/11/25 Hans-Christoph Steiner <hans at at.or.at>
> >>
> >>
> >> [writesf~]
> >>
> >> .hc
> >>
> >> On 11/25/2012 05:03 AM, Pierre Massat wrote:
> >> > Or is there a way to directly pipe Pd's audio output into another
> >> > program?
> >> > Too bad JAC doesn't work on the Pi...
> >> >
> >> >
> >> > 2012/11/24 Pierre Massat <pimassat at gmail.com>
> >> >
> >> >> Hi,
> >> >>
> >> >> I 've been searching the internet for two days and i couldn't find
> any
> >> >> satisfying answer, so I thought I'd ask here...
> >> >> I'm running PD on my Raspberry Pi, and I need to record Pd's output.
> I
> >> >> can't use the standard writesf~ because I lack disk space, and
> >> >> oggwrite~
> >> >> doesn't work well on the RPi (it records fine but Pd's output is
> >> >> trashed).
> >> >>
> >> >> I recently discovered that i could record something in raw with ALSA
> >> >> using
> >> >> arecord, and pipe this into oggenc, or flac, or whatever I need to
> >> >> record
> >> >> the file. Something like:
> >> >> arecord <parameters> raw | oggenc <parameter> file.ogg
> >> >>
> >> >> The thing is that the RPi has no capture device (the single PCM
> doesn't
> >> >> seem to be capable of capture).
> >> >>
> >> >> A lot of things seem to be possible using a .asoundrc configuration
> >> >> file
> >> >> for ALSA, but I don't know how to use it.
> >> >> What I would want is to copy the PCM output so that ALSA can
> recognize
> >> >> this copy as an input in a record. Note that I need to be able to
> >> >> listen to
> >> >> the output while recording.
> >> >>
> >> >> Do you thing this is possible at all?
> >> >>
> >> >> Cheers,
> >> >>
> >> >> Pierre.
> >> >>
> >> >
> >> >
> >> >
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