PulseAudio sound plugin causes choppy playback running Scratch

[Amos Blanton]

Binary package hint: squeak-vm

When running Scratch with this VM (1:3.11.3+svn2147-1ubuntu1 ) on Lucid, sound playback using the vm-sound-pulse plugin is choppy, as is sound recording.
To test:
1. Install squeak-vm and Scratch (http://info.scratch.mit.edu/Scratch_1.4_Download )
2. Run Scratch using this VM, rather than the one that is currently bundled with it:
squeak -vm-sound-pulse /usr/lib/scratch/Scratch.image
3. Select Scratch Cat sprite. Click "sounds" tab, play button on "meow."

The current version of Scratch bundles its own VM and pulse plugin that works well (just run scratch without specifying this vm to test). The source code for the vm-sound-pulse plugin that Scratch uses is available here, as is the binary:
http://my-svn.assembla.com/svn/scratchonlinux/trunk/scratch/src/plugins/vm-sound-pulse/

[Luke Faraone (lfaraone)]

Interesting. I'm getting even more alarming behavior on my amd64 system:

lfaraone@Opus:/tmp/tmp.38NXQsoKzV/scratch$ squeak -vm-sound-pulse Scratch
found gettext in path
/tmp/tmp.38NXQsoKzV/scratch
openPulseAudio() play, rate: 22050, chans: 2
sound_Start() frameCount >> 1: 1322

Segmentation fault

10292688 [] in SoundPlayer class>playLoop
10281488 Semaphore>critical:
10281396 SoundPlayer class>playLoop
10292384 [] in SoundPlayer class>startPlayerProcessBufferSize:rate:stereo:
10292476 [] in BlockContext>newProcess
/usr/bin/squeak: line 277: 17489 Aborted (core dumped) $VM "$1" "$2"

I'll test this in a 32-bit Lucid VM.

[Rik Smoody (squeak)]

I also see
found gettext in path
when starting squeak on an amd64 Ubuntu 10.04 alt

[David Farning (dfarning)]

Due to upstream liscenseing restrictions and limited developers we will not be developing and supporting official scratch packages.