Re: OSRL Presents: A World Exclusive - SCAMP has arrived

[CUTblakeney@home.com (Jeff Blakeney)]

On 29 Nov 1999 23:19:31 GMT, cturley2@aol.com (Cturley2) wrote:

>Remember to always download the SCAMP file as a raw binary file ONLY!  You can
>only play the SCAMP files on the IIgs with the GS/OS application Oversampler.

You can probably play them with the program LongPlay too as neither
have any special support for WAV files.  They are just treating WAV
files as raw binary sound files and causing a little click at the
beginning of playing back the sample due to the few bytes of header
information that is stored in a WAV file.

>You can leave them exactly as they are, without any need or reason to change
>the file type at all. When you select and load each of the two SCAMP files with
>Oversampler, make the following program settings within the Oversampler
>program, before you select the play option.
>
>Volume: 255
>
>Frequency: 420
>
>Echo Delay: 2
>
>Oversampling: off
>
>Stereo is the default sound mode. If you don't have a stereo card, present and
>active in your IIgs, then you can't have stereo sound. Thus, you could set the
>sound mode to Internal and avoid any needless demands to your IIgs CPU.

First off, what makes people think that Oversampler can play stereo
sound samples?  As far as I can tell from the documentation and from
the fact that this program is designed to play raw binary sounds,
Oversampler does not support stereo sound samples.  The Output option
is just to allow the program's volume control to work properly with
either a stereo output card or the internal speaker or to output to
only the left or right channel exclusively.  The programmer says in
the documentation that the left and right channel options he wasn't
sure why he included them but they could be used to test you stereo
output card for operation.  :-)

Another clue that Oversampler doesn't support stereo samples is that
the documentation says that the Echo option uses the left channel to
play the sound sample and the right channel plays the same sample but
delayed slightly and at 3/4 the volume of the left channel.  Kind of
hard to play a stereo sample when you are using the left and right
outputs this way.

The final clue that Oversampler doesn't support stereo samples is the
fact that the WAV files in question here are 8 bit, 11,025 Hz stereo
samples.  According to the Oversampler documentation, that would mean
setting the frequency option to 214 or 215 (11025 / 51.406 = 214.47).
However, a stereo sample has both channels in a file so the file
becomes twice as big so if you played it as a mono sample you would
have to play it at twice the frequency to get it to sound right.  This
would mean setting Oversampler's frequency option to 428 or 429 (22050
/ 51.406 = 428.94).  As this is pretty darn close to the 420
suggested, I'd say that the stereo sample is being played as a mono
file.

This means that you could probably get an even cleaner sounding
version of the MTR.WAV file by making a mono sample and you would also
end up with a file that is only around 689,479 bytes long which is
much better than the 1,378,958 bytes it is now.  You would also be
playing back at the 214/215 rate so you won't need as fast a drive to
do the 2 or 4 times oversampling.

Which brings me to my next point.  Why suggest playing back a sample
with oversampling turned off?  One of the big advantages of this
program is to allow 2 or 4 times oversampling so that the play back
sounds better than the original file.  As long as the drive you are
playing the sound sample from can handle it, use the 2 or 4 times
oversampling option.  It will cut down on a lot of the noise in a
sample.

However, even with all these points, there is no way an 11,025 Hz, 8
bit mono sample is ever going to sound better than a 44 kHz, 16 bit
stereo sample.  Using the oversampling and echo options in Oversampler
can give some decent sounding play back on a IIgs but is still isn't
as good as an MP3.

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| Jeff Blakeney - Dean of the Apple II University in A2Pro on Delphi     |
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