On 10 Feb 93 22:16:00 GMT, Ed Hall <edhall(_at_)rand(_dot_)org> said:
Ed> In article
<9302102116(_dot_)AA12266(_at_)cbfsb(_dot_)cb(_dot_)att(_dot_)com>
Ed> mark(_at_)cbfsb(_dot_)cb(_dot_)att(_dot_)com writes:
Mark> . . . .
Mark> By the way, what is the core Audio format? I get the uneasy
Mark> feeling it's "whatever Sun's /dev/audio understands" which
Mark> makes me very nervous.
Ed> Well, no, 8-bit u-law is actually a national standard for telephone-
Ed> quality audio. (Europe uses a similar but not idential A-law
encoding).
Ed> The fact that Suns support this format isn't a coincidence--it is a
Ed> result of Sun using a digital telephone interface chip for their
audio
Ed> port. But the standard preceded /dev/audio, not the other way
around.
Indeed.
Ed> I think it's a good choice, irrespective of Sun's support for it.
Ed> Better than 8-bit linear (with its limited dynamic range),
Ed> thriftier than 16-bit linear, and not CPU-consumptive, like more
Ed> highly compressed formats.
I can't say I agree here. Looking at recent history, CPU performance
increases MUCH faster than available bandwidth, especially among
connected LANs. And while ATM promises greater speed soon, it will be
a while before all the ethernet machines go away; ATM will initially
be deployed as a wide-area technology.
Most mail traffic is across local nets, at least in the Environments
I have seen. Since having a machine that can play back sound usually
means having a CPU on your desktop, it is only neighborly to trade
your personal CPU for reduced network (public) impact.
Don't get me wrong; U-LAW is a pretty good choice (for americans!) of
a standard, but suboptimal. A compressed type should have been the
standard (4-bit, g.721 ADPCM?) and should be registered pretty soon.
Changing the base audio type, I think, would constitute a rather too
substantive change to the spec at this late date.
-Rens
__ ___ , __
/__) /__ /| / ( | J. Laurens Troost Lehman Brothers Technical Services
/ \ (___ / |/ __) | *Opinions expressed herein are mine. Mine, I tell you!*
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