Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!olivea!mintaka!bloom-beacon!eru!hagbard!sunic!news.funet.fi!funic!santra!hila.hut.fi!jmunkki
From: jmunkki@hila.hut.fi (Juri Munkki)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Simultaneous Sampled Sounds w/ System 7
Message-ID: <1991May1.122319.14091@santra.uucp>
Date: 1 May 91 12:23:19 GMT
References: <8c7M7sW00WBNE1N7Fv@andrew.cmu.edu>
Sender: news@santra.uucp (Cnews - USENET news system)
Reply-To: jmunkki@hila.hut.fi (Juri Munkki)
Organization: Helsinki University of Technology, FINLAND
Lines: 30

In article <8c7M7sW00WBNE1N7Fv@andrew.cmu.edu> jp57+@andrew.cmu.edu (Jefferson Provost) writes:
>The new Sound Manager docs claim that the new sound manager has the
>ability to play multiple channels of sampled sound simultaneously, but I
>can't seem to get it to work.  I allocate a channel and play a sound,
>and then, while it is still playing, I allocate another channel and play
>another sound, but the second channel seems to overide the first channel
>and the first sound gets cut off.   I'm playing the sounds with
>SndPlayDoubleBuffer() (I need low level control), and I've tried various
>initializations for the sound channels (initSRate22k, initNoSRC).  I've
>also tried the first sound in the right stereo channel and the second
>sound in the left stereo channel with the same result.

I use one channel with SndPlayDoubleBuffer and if another application uses
SysBeep, the beep is clearly audible, although both sounds drop 50% in volume.

My guess is that either your program has bugs, or the sound manager doesn't
support two channels of SndPlayDoubleBuffer. Try your program with just one
channel of double buffered sound and one normal channel to see if it works.
If it does, you can suspect the sound manager feature. If it doesn't work,
then your code must be at fault.

As long as you are using SndPlayDoubleBuffer, why don't you mix your sounds
yourself using just one SndPlayDoubleBuffer? That's what I'm doing to get
two sound channels. Your routines will probably be much faster than the more
general sound manager mixing routines.

   ____________________________________________________________________________
  / Juri Munkki	    /  Helsinki University of Technology   /  Wind  / Project /
 / jmunkki@hut.fi  /  Computing Center Macintosh Support  /  Surf  /  STORM  /
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~