[comp.sys.apple] Gs sounds

GREYELF@WPI.BITNET (04/24/89)

How does one interpret the data in a Gs cound file?
How does one play the data back?
Is it midi?  How is midi data interpreted?

I have a Laser 128, and as I will soon be giving it stereo sound
output that would make the GS sound bad, I want to know how to
interpret existing sound files too...

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wombat@claris.com (Scott Lindsey) (04/26/89)

From article <8904252315.AA04687@wpi>, by GREYELF@WPI.BITNET:
> Does anyone have any information on the construction/playback of
> GS sound files?
> 

One thing to experiment with is the recently available GS source samples.
One of the programs plays back digitized sounds.  For those types of sounds,
the data is simply amplitude with $80 being 0 amplitude [1 is minimum amp &
$FF is max .. 0 tells the generator to shut down.  You have to decide what
sample rate to use.  I don't know what hardware is available for the GS for
actually sampling sounds.  I've used sounds from the Mac (usually created
with MacRecorder) without problems (after I found that 0's should be changed
to 1's in the data).

There is not, as far as I'm aware, any standard format for sound files other
than raw data (which doesn't tell you the sample rate).

-- 
Scott Lindsey     |"Cold and misty morning. I heard a warning borne in the air
Claris Corp.      |    About an age of power when no one had an hour to spare"
ames!claris!wombat| DISCLAIMER: These are not the opinions of Claris, Apple,
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MSER001@ECNCDC.BITNET (04/26/89)

re: sounds.  Apple had (probably still does) a document on disk called

Audio Interchange File Format: "AIFF"
A Standard for Sampled Sound Files
Version 1.2
Apple Computer, Inc.

The Audio Interchange File Format (Audio IFF) provides a standard for storing
sampled sounds.  The format is quite flexible, allowing for the storage of
monaural or multichannel sampled sounds at a variety of sample rates and
sample widths.
..
Audio IFF conforms to the "EA IFF 85"  Standard for Interchange Format Files
developed by Electronic Arts.
..
All data is stored in Motorola 68000 format.  Data is organized as follows:
..
On an operating system that uses file extensions, such as MS-DOS or UNIX,
it is recommended that Audio IFF file names have a ".AIF" extension.
..
So...one would assume that the Audio IFF is not for the IIGS, as the IIGS
was not mentioned in the documentation?  I do know that the mac recorder
(sorry murph) does have the IFF format.  Also Apple may have a newer version
of the docs.

srh  mser001@ecncdc.bitnet

mattd@Apple.COM (Matt Deatherage) (04/27/89)

In article <8904260929.aa20607@SMOKE.BRL.MIL> MSER001@ECNCDC.BITNET writes:
>..
>So...one would assume that the Audio IFF is not for the IIGS, as the IIGS
>was not mentioned in the documentation?  I do know that the mac recorder
>(sorry murph) does have the IFF format.  Also Apple may have a newer version
>of the docs.
>
>srh  mser001@ecncdc.bitnet

We spent a fair amount of grief in March and April translating the AIFF specs
into II and IIgs-specific format.  This was published in March as File Type
Note for file type $D8/auxtype $0000.  Those of you who have paper copies
already know this; those who get text files off the net should have them within
a week, says Mark Johnson who stands right here.

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