mp3s sound funky on Squeak ( Windows )

Brent Vukmer bvukmer at blackboard.com
Fri Aug 23 18:48:55 UTC 2002


Thanks alot for your advice, John. Everything ( AbstractSound, Speaker, MpegPlayer, PianoKeyboard, etc. ) sounded fine after I bumped the SoundPlayer BufferMSecs up to 155 and restarted SoundPlayer. 

I haven't figured out the underlying problem, though.  I'm seeing this behavior on a desktop PC that I use for development at work.  It's got a lot of background processes running, but the Windows Task Manager shows plenty of cycles/RAM left.  I don't have any other media players running, and I don't _think_ I have any other processes running that would hork up sound.

I opened up the System Information console and found the following:

System Information report written at: 08/23/2002 02:40:15 PM
[IRQs]

IRQ Number	Device
9	Microsoft ACPI-Compliant System
9	Matrox Millennium G450 Dual Head - English
9	Adaptec AIC-7892 Ultra160/m PCI SCSI Card
9	Texas Instruments OHCI Compliant IEEE 1394 Host Controller
9	3Com 3C920 Integrated Fast Ethernet Controller (3C905C-TX Compatible)
9	Intel(r) 82801AA USB Universal Host Controller
9	AC'97 Driver for Intel(r) 82801AA Controller


Could all of these devices sharing the same IRQ, possibly create sound issues?

-----Original Message-----
From: Maloney, John [mailto:John.Maloney at disney.com]
Sent: Monday, August 19, 2002 8:53 PM
To: squeak-dev at lists.squeakfoundation.org
Subject: Re: mp3s sound funky on Squeak ( Windows )


Brent,

Another quick test of the Squeak sound system is:

  AbstractSound stereoBachFugue play

If this comes out garbled or with stutters/dropouts, then it may be because Squeak isn't
getting enough processor cycles to compute sound buffers in time. That same problem
would affect MP3 playing. If this is the case, some things to try are:

  1. quit from all applications other than Squeak (especially other media players!)
  2. turn off as many background jobs as possible
  3. if you are on a laptop, check your power management settings; if there is
      a "power cycling" or "power conservation" mode, try disabling it
  4. you might have trouble with MP3 if you're running on very old, slow
      hardware (seems unlikely, given that you're running Win 2000)

If all of that fails, you can increase the size of the sound buffer by editing
SoundPlayer class>initialize. Then execute the comment at the top of that
method, "SoundPlayer initialize; shutDown; startUp" to make it take effect.

When you figure out what the problem is, drop us a note and let us know...

The Bach fugue example plays perfectly on my Windows 2000 machine
(an IBM Thinkpad).

	-- John


At 11:53 AM -0700 8/19/02, Brent Vukmer wrote:
>When I open the MPEGPlayer on a 3.2 image or a 3.3a image, and select an MP3 file, then press the play button -- it plays, but it sounds really, really garbled.  How should I troubleshoot what's going on?
>
>I'm running on Windows 2000 and I should have the latest updates for both 3.2 and 3.3.
>
>
>Thanks,
>Brent






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