Subject: Re: MP3 decoder?
From: supertimer@aol.com (Supertimer)
Newsgroups: comp.sys.apple2
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NNTP-Posting-Host: ladder07.news.aol.com
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Date: 20 Aug 1999 03:53:40 GMT
References: <labelas-1908991952120001@host-216-76-180-77.psl.bellsouth.net>
Organization: AOL http://www.aol.com
Message-ID: <19990819235340.09743.00001791@ng-fg1.aol.com>



labelas@hotmail.com (Labelas Enoreth) wrote:

>supertimer@aol.com (Supertimer) wrote:
>
>> I've done it before.  In fact, I have quite a collection of large audio
>> files on my IIGS hard drive.  I use the PC to do the decoding,
>> down it to about 22Khz or 44Khz at 8-bit mono (I've done both, but
>> the 44Khz convert less because it slows down on my PC since
>> I've only got 32MB of RAM and Windows has to generate a huge
>> swap file to do the processing).  I then save it as a raw, unsigned
>> format sound file onto an MS-DOS Zip disk.  The Ensoniq's
>> frequency balance is a little different than my PC's sound card
>> and my IIGS speakers are also a little different, so I also use
>> the graphic equalizer to adjust before saving to Zip disk.
>
>Ah. This in itself is interesting, but I think I knew of it already...I
>was simply curious if someone had actually made the time to write a
>utility to convert a MP3 on a IIgs, which to me seems unfeasible and such.

You never know.  They've ported a raytracing program to
the IIGS after all, as well as a 3D modeling and animation
program.  The basic idea is let the conversion take place
overnight and retrieve the finished product tomorrow
morning.  Or evening.  ;-)

>Although I wonder how you would 'down' to 44khz...Are there MP3s out there
>in, say, 88khz or something? Heh. I can listen to a gigantic high-quality
>16-bit stereo AIFF on this computer with no slowdown at all, and it's a
>'getting long in the tooth' centris 610 with 32mb of ram. I'm even
>listening to one right now as I type here, download a file with FTP, and
>have a big picture file open...guess just goes to show the inefficiency of
>windows when compared to the illustrious Mac. :P

Oh, no that's not what I mean.  I can easily listen to an MP3
file in real time in Windows and download with FTP, edit
photos, etc.  What slows Windows down is CONVERTING
MP3's to waves because it needs to create a huge temporary
file on disk.  ;-)

I should be getting a kick butt Mac emulator for my PC soon,
btw, after I put a faster CPU chip in it.

>> I could send you a sample conversion if you have your own
>> ftp space with an incoming folder or I can walk you through
>> your own conversions need be.
>
>Nah, it's ok. I know what you mean. I'm happy enough listening to AIFFs on
>my mac though, it would be way too much work to get them onto the IIgs
>just so I can listen to them through that crummy little speaker. And I
>don't feel like dragging the Apple speakers out there.

Too bad.  In actuality, the conversions, when listened to on
the IIGS with proper speakers, are actually quite faithful to
the original MP3s.

For the record, Oversampler on the IIGS does not take
AIFFs.  They take a type of WAV file.  Specifically, 8-bit
unsigned.  I think AIFFs are always signed (not sure).
Waves can be signed or unsigned.  Oversamply takes the
unsigned ones.