Matt Jarvis wrote:
> ...In terms of actual recording time,
> a 4GB file would equate to 5 hours
> in uncompressed linear PCM...
I think it's actually a bit more
than 5 hours:
for stereo DAT quality recording:
48,000 samples/second*16 bits/sample =3D 768,000 bits/second
double this for stereo =3D 1,536,000 bits/second
divide by 8 for bytes =3D 192,000 bytes/second
multiply by 60 =3D 11,520,000 bytes per minute
multiply by 60 =3D 691,200,000 bytes per hour
A gigabyte of disc storage =3D 2**30 =3D 1,073,741,824
So a 4 Gigabyte disc stores 4,294,967,296 bytes
divide 4GB by bytes per hour =3D
6.2 hours of stereo DAT-quality recording
Even allowing for some storage loss due to
cluster size and hard disc overhead, I think
the length of recording would be closer to
six hours than five hours.=20
Double the recording time by recording in
mono instead of stereo, if mono works for your
application.
Of course, you'd have to find a way to provide
external power since the internal batteries won't
last this long!
4GB Microdrive devices in Type II packaging
are expected from Hitachi/IBM by this Fall, and
Type I Sandisk 4GB compactflash cards will be available
in two to three months.=20
Price will likely be close to $1,000 for either
device when introduced. Prices have been falling
75% per year in the compactflash market, so I'd
expect pricing to be less than $500 this time next year.
--oryoki
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