Subject: Re: MP3 conversions disc for IIGS?
From: [email-masked] (Supertimer)
Date: 25 Jan 2002 15:40:46 GMT
Newsgroups: comp.sys.apple2

Louis Cornelio <[email-masked]> wrote:

>[email-masked] (Supertimer) wrote:
>
>> But
>> as a PC user, I can do even MORE for the IIGS.  Now I
>> have a CD burner in my PC so I was wondering, how many
>> IIGS users would be interested in a CD-ROM compilation
>> full of MP3s converted to IIGS format? 
>
>whoa! But what "IIGS format"? what would you use to play them?
>& of course once converetd - are they mp3 anymore? Or just another sound 
>file (whetever format you are using) sourced from mp3?

$D8 and aux type as $0200

A PC wave file saved with the attributes mentioned in my article
and set with file type $D8 and aux type $0200 will be recognized
by the Oversampler, the IIGS digital audio playback program.

The file won't be an MP3 anymore.  Oversampler replaces the
MP3 compression with interpolation.  The file is first converted
to a standard wave file on the PC which is then reduced in size
by downsampling to 26360Hz.  On the IIGS side, Oversampler
then "oversamples" the file at either 2x or 4x to gain back
quality while maintaining a reduced file size.

Another option would be to take the 44.1kHz wave file itself
and save that with the right attributes for the IIGS and use
Oversampler to play it at 1x sample rate.  However, because
the file no longer has MP3 compression, it will be very large
this way and as mentioned in my article, the IIGS power
supply has interference.  In my experimentation, I have found
that in order to make the 44.1kHz file sound right, you would
have to upsample the file to 52720Hz (2x 26360Hz).  This
will give you the best sound quality at the expense of even
more disk space.

Oversampler is a streaming audio player so you don't need
7MB of memory to play a 7MB audio file.  If you can load
GS/OS and Oversampler, you can play any audio file.