Format of voice files on unix pc

[David Solan]

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G. Mark Stewart recently posted a question on the format of voice
files on the UNIX PC (for those who have Voice Power Boards).  As
far as the 16K and 24K voice files are concerned, I believe you just
better forget them -- as I understand it, they are VERY complicated.

However, the 64K voice files very simply break up sound into
64,000 "bits" per second.  I don't think the sound is put out in the
form of absolute amplitudes at all, but rather in the form of
RELATIVE amplitudes -- that is, each bit tells you whether the sound
rises or falls in amplitude relative to the previous bit.  Thus, in
order to get a waveform from this numeric output, you'll have to
perform sort of numeric integration.

It is true that there are headers on these voice files, but at
least for the 64K ones it doesn't seem to make much difference if
you clobber them or not -- at least they sound the same when played
back no matter what happens to the headers.

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David  Solan
Objective Programming Incorporated
Post Office Box 123
Norwalk,  CT  06856
Voice: (203) 866-6900
attmail: dsolan
USENET: gizzmo!kdavid

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David Solan                            rutgers!rochester!pcid!kodak!gizzmo!mark
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