Sound Recording on Mac

Yoshiki Ohshima yoshiki at squeakland.org
Thu Nov 9 02:00:46 UTC 2006


  Hello,

  Has anybody tried sound recording and playback on Mac lately?  Scott
reported that it is broken in Squeak 3.9 7067 (and OLPC etoys image)
on 3.8.12beta4U.app VM.  What happens is that if you record your voice
with a SoundRecorderMorph or EventRecorderMorph (with the voiceControl
enabled) and play the recorded sound back, you get incorrect sound.

  Here is what Scott described:

--------------------------------------
(a)  The sound-in-event-recorder bug *does* occur [in 3.9 7067].  But it's slightly  
different:  although the speed of playback is nearly doubled, as in  
OLPC, the *pitch* does not change.  So it is not a Donald Duck sound.

(b)  Also, the same bug now (i.e. in 3.9) also occurs in the vanilla  
SoundRecorderMorph!  (In the OLPC/Mac image, the vanilla  
SoundRecorderMorph produces good playback on the Mac -- it's only the  
use of sound within an EventRecorderMorph that's problematical.  In  
the 3.9/Mac image *every* SoundRecorderMorph use has this problem.   
But again, the overly-fast playback occurs *without* a pitch rise.)

So evidently 3.9 went "final" with the SoundRecorder completely  
broken on the Mac.
--------------------------------------

  Can anybody confirm this?  Since the same code works on Windows (and
presumably on Linux), we kind of suspected a bug in the Mac VM causes
the 'stereo' value or sampling rate set incorrectly...  Does anybody
has an idea?

-- Yoshiki



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