[squeak-dev] recording sound on *nix via ALSA libs

David T. Lewis lewis at mail.msen.com
Sun Feb 22 20:27:32 UTC 2015

On Sun, Feb 22, 2015 at 10:48:44AM -0800, tim Rowledge wrote:
> I?m attempting to hook up the scratch sound recording on Pi; which amongst other things requires setting up add-on hardware that may or may not work, be comprehendable, or even taste of the correct chocolate .
> Before I get too lost in trying to work out why things don?t work I would love to know if anyone has been able to use ALSA libs to record on any machine/*nix version/hardware? Just knowing a workable configuration exists would be helpful.

On a trunk image, if I enable the shared flaps, then drag a "Sound" morph
from the Widgets flap, I can record and play awful sounding things with
an interpreter VM running whatever it gets hooked up to on my Ubuntu box.

If I specify -vm-sound-pulse, I get fairly good audio quality.

If I specify -vm-sound-ALSA, I get a primitive failure with this error on
the VM console:

  sound_StartRecording: snd_add_pcm_handler: Function not implemented

If I use a precompiled interpreter VM or Cog VM on my system, and specify
-vm-sound-ALSA, I get this error on the VM console:

  ALSA lib conf.c:3314:(snd_config_hooks_call) Cannot open shared library libasound_module_conf_pulse.so
  ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM default
  start_SoundRecording: snd_pcm_open: No such file or directory

The primitive failure is for primitiveSoundStartRecording in the SoundPlugin.

I think that the ALSA support code is out of date with respect to the
libraries provided in current Linux distributions.

There are several issues related to ALSA on bugs.squeak.org. This one looks
like the issue I am seeing, and may give you an idea of what needs to be done:



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