[comp.sys.mac] Sound Resources for Mac II

mark@apple.UUCP (Mark Lentczner) (11/02/87)

In reference to the current disscussion about Sound Resouces on the Mac II
someone said something about haveing sounds sampled at a different rate
and wanting a program to re-sample them to the right sample rate for the
Mac II.

You DO NOT NEED to do this!!!  It only doubles or quadruples the number of
samples in the file.  The SoundManager in the Mac II will happily re-sample
the sound at play time!  All you have to do is look in the header of the 
snd resource (either type 1 or type 2) and change the sample rate constant.
The Sample rate constant tells the Sound Manger what sample rate the sound
was sampled at.  It is a 32 bit fixed-point number (binary point in the 
middle).  For various sample rates the proper values are:

	44,100.00hz (CD Rate)	AC44 0000
	22,254.54hz (Mac Rate)	56EE 8BA2
	11,127.27hz (Half Mac)	2B77 45D1
	 5,563.63hz (Quarter)	15BB A2E9

In any of the system beeps you should find the value for mac or half mac
I don't remember what offset the value is stored at, poke in the system
ones to see.

-Mark Lentczner
 ATG Graphics & Sound Group
 Apple Computer, Inc.
 20525 Bandley Drive, MS:22Y
 Cupertino, CA 95014

 mark@apple.CSNET
 {dual,ios,voder,nsc}!apple!mark.UUCP
-- 
-Mark Lentczner
 ATG Graphics & Sound Group
 Apple Computer, Inc.
 20525 Bandley Drive, MS:22Y
 Cupertino, CA 95014

 mark@apple.CSNET
 {dual,ios,voder,nsc}!apple!mark.UUCP