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Re: porting from linux
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Re: porting from linux


  • Subject: Re: porting from linux
  • From: Michael Ashton <email@hidden>
  • Date: Fri, 10 May 2002 20:22:43 -0700

On Friday, May 10, 2002, at 08:14 AM, Yves de Champlain wrote:

Right now, when I load a sound, it comes in much too loud, clipping all the way through. I have to greatly reduce the gain of the wave file before trying to load it. Then it will come out OK but if I try to mix down to disk it gets some channels too soft some loud.

I don't know much of anything about OS X sound (yet), but this doesn't sound like a byte-swap problem to me. If the bytes were swapped, you'd hear loud noise; it wouldn't sound like the original material at all. (I'm assuming here that you have 16-bit data.)

One possibility is a binary format mixup. If you were to send two's-complement when it was expecting straight binary, for example, you might see this kind of thing - although I'd imagine it would be severely distorted. 2s-comp to straight binary would invert the negative portions of the wave and send them through the roof. That doesn't sound like your problem.

Straight binary to 2's comp would come out sounding not-so-loud sometimes, and other times like it was clipping and distorting, when the amplitude got in to the upper half. (Full-range data would sound clipped all the time.) Gaining it down would sort of fix the problem, since you'd be keeping the wave in the lower half of the amplitude range; but you'd have problems mixing, since all of your data would have a nice big DC offset in it, if interpreted as 2's comp. So maybe that's what it is.

Try making sure your data is 2's complement, and if it isn't, convert it to 2's complement. I don't know which one WAVE is.

regards
Michael Ashton <email@hidden>
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References: 
 >porting from linux (From: Yves de Champlain <email@hidden>)

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