Found it.

In the Unix code  sqUnixSoundMacOSX.c

  OSStatus bufferDataProc(AudioConverterRef inAudioConverter, UInt32  
*ioDataSize, void  **outData, void  *context)
{
...
   if (!n1)
     {
        char empty[256];
       *ioDataSize= min(256, *ioDataSize);
       *outData= (void *)empty;
#    if (DEBUG)
       putchar('-');  fflush(stdout);
#    endif
     }
   ...

One should NOT assume that char empty[256] will in fact result in a  
byte string containing 256 zero bytes, rather we get something  
not-zero, thus a buzz.
I also wonder about the *outData = (void *) empty if *ioDataSize is  
actually < 256 bytes.
Seems to me one should do a memset(outData,0,*ioDataSize);  to ensure  
zeros and not walking off the end of a small outData buffer...


A 3.8.6b6 is pending, awaiting further feedback.


On Feb 5, 2005, at 7:46 AM, Bert Freudenberg wrote:

>
> Am 05.02.2005 um 07:54 schrieb John M McIntosh:
>
>> 3.8.6b5 uses the Unix CoreAudio sound plugin which apparently allows  
>> you greater flexibility in recording rates.
>> Folks should confirm recording and sound playback works as in the  
>> past since we have dropped the ancient sound input and carbon based  
>> double buffering for sound playback.
>
> Recording works fine. However, on playback I sometimes get a a very  
> sharp, short noise - most often when playing the first sound, once  
> when quitting, sometimes in between.
>
> It's a bit hard to reproduce, but I get it fairly consistently when  
> dragging an object from the object catalog and immediately dropping it  
> back onto the catalog (don't know which sound that is), the first time  
> after starting the image.
>
> This is a G4 Titanium running 10.3.7 ...
>
> - Bert -
>
>
>
--
======================================================================== 
===
John M. McIntosh <johnmci at smalltalkconsulting.com> 1-800-477-2659
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
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