Re: CDR's & MP3 for GS???

[spec@vax2.concordia.ca (Mitchell Spector)]

In article terryolsen@aol.comRemoveMe (TerryOlsen) writes...

>Has anyone ever came up with a program and/or drivers for using
>CDR burners on the GS?

    To the best of my knowledge, no software drivers exist to
support this. Another issue is despite there being SCSI CD-R
drives, I'm not so sure about the feasibility of the Apple HS
SCSI or RamFAST SCSI (or the IIgs itself) being able to support
them on the hardware level.

    At the moment the only solution is to move data you want
archived over to a PC or Mac and burn it there.

>What about an MP3 player???

    That is completely out of the question. An MPEG1, Layer 3
player has to read data and decompress it *on-the-fly*, while
at the same time, play what has been decompressed so far. It's
kind of like driving a high-speed train with a track building
robot just a few feet in front, laying down track for the train
to travel on _as_ it drives--if the robot stumbles or is too
slow, your going to have a big problem if the train gets ahead
of the robot and the unfinished track. :) Not too long ago I
used to use a 133 MHz 486 machine to play MP3 files, and that
was not able to keep up (I was able to _just_ squeeze by if I
didn't touch the mouse or keyboard while it played).

    So a player is out of the question, but (at least in theory)
an MP3->WAV convertor could be written. There would be some big
catches though. Even with a 16 MHz accelerator it would still
probably require an overnight job, or possibly an entire day, to 
decompress the data. Next problem is the resulting waveform would 
be several megabytes large, quite often *larger* than 32 MB (the
limit of ProDOS) so you would need quite a large and ample HFS
partition to store the finished file. Next problem, the resulting
file once converted would be 16-bit audio, and the Ensoniq in the 
GS can only handle 8-bit audio, so you'd need another step in the
converting process, dropping it down from 16 bit->8-bit.

    Now we can listen to the audio, right? Wrong. Even though
you would now have an 8-bit, 44 kHz, stereo audio file, it
would be several megabytes large, so you would need a program
that could spool the file in and out of memory as it played
(most GS players want to load the entire waveform into memory
before playing it, and 4-8 MB would not be enough). I believe
there is a program called "LongPlay" which does do spooling,
but can it support stereo audio? If not, you'd need to convert
it once again, from stereo->monorail. Of course in the end your
killing the whole point of MP3 format--CD quality audio that
takes up a relatively small amount of space (your average MP3
file is about 3-4 megabytes large). Not very practical at all,
except for very small MP3's--like say something that is 15
seconds of monorail sound recorded at 11 kHz and compressed
using a 16K bit rate (that might decompress to 1 MB or less, 
wouldn't require an overnight session and was never CD quality 
to begin with). MP3 is a file format you want a Pentium or
PowerMac to handle.

Mitchell Spector
spec@vax2.concordia.ca