Convert

Here's a quick little hack that takes Mac 8-bit digitized sound files, and converts them to NeXT 16-bit sound files.

Usage:
    
    convert [-22] filename
    
The program takes a Mac sound file "filename" as input, and outputs a NeXT sound file "filename.snd" as output.
    
Mac Sound Files:

I don't know much about these files, I just got my hands on a bunch of them and tried to convert them.  I don't know what "official type" they are or anything.
They seem to be a series of 8-bit samples, with no header.  The sample speed doesn't seem to be included in the file either (so you have to guess).  The most common speed seems to be 11 kHz sampling, so that is the default of my program.  If that seems to slow, you can redo it with the '-22' switch, which translates the file as a 22 kHz sample.
The samples seem to be 0x80 based.  Everything about 0x80 is a positive level, and everything below 0x80 is negative.

NeXT sound files:

I don't know much about these files either (I couldn't find them in the docs).  These guy do have a header.  Much of my info is guessed by looking at other files.  All header values are 4 byte integers.

1	Magic Value = 0x2E736E64
2	Offset to start of sound (all offsets are from begining of file)
3	Offset to end of sound (this value is not used by the NeXT librarys (?).  SoundPlayer and SoundEditor both work  without this value, so I set it to 1+[offset to start])
4	?? - set it to 3  (Sound file type?)
5	Sampling frequency (1F4C = 8 kHz, 5622 = 22 kHz, ?? = 44)
6	set it to 1 (this could be the stereo flag.  I don't think the Mac sounds are in stereo)
7-8	space-filler?  (the NeXT has it so I do too!)
	
The NeXT sounds are a 16-bit two's complement number.
    
As you can tell, I don't have complete info about these formats, but enough for the conversion.  If you have more info, please send it to me.

USE THIS PROGRAM AT YOUR OWN RISK.  I'm not responsible for any damage to your computer in any way.  (My speaker didn't blow out!)  Since there's no header on the Mac files, my program cannot tell if it is really sound or not.  It will convert any file to the NeXT sound file format.

Please send me bug reports, or suggestions.

	Robert Hood
	hoodr@csus.edu