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From: caserta@athena.mit.edu (Francesco Caserta)
Newsgroups: comp.unix.shell
Subject: Re: Audio
Keywords: Audio Shell
Message-ID: <1991Jun15.024327.22211@athena.mit.edu>
Date: 15 Jun 91 02:43:27 GMT
References: <1991Jun7.134254.11485@citib.com> <14083@dog.ee.lbl.gov>
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Organization: Massachusetts Institute of Technology
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In article <14083@dog.ee.lbl.gov>, torek@elf.ee.lbl.gov (Chris Torek) writes:
|> In article <1991Jun7.134254.11485@citib.com> scairns@citib.com
|> (Scott Cairns) writes:
|> >... The following was suggested by <barmar@Think.COM>:
|> >>       % record | rsh [hostname] play
|> >which worked just fine.  He then followed up with this question:
|> >>	I was curious about how well this would work.  Is the bandwidth of
|> >>	Ethernet good enough for real-time sound like this?
|> 
|> The bandwidth of Ethernet is plenty---the SparcStation /dev/audio
|> takes only 8000 samples per second, i.e., 8 KB/s (using ulaw encoding
|> to compress 12-bit samples to 8-bit values).  Ethernet is entirely
|> capable of sending 1.25 MB/s; 8 KB/s is trivial.
|> 
|> >It's not exactly "real-time" of course.  With:
|> >
|> >% record -v 50 | rsh [hostname] play -v 50
|> >
|> >you have to wait for record(6) to do a flush(3) before it pipes
|> >over the network to rsh(1) so there is a second or two of latency.
|> 
|> This just means you have to write more code; the provided shell-level
|> tools will not do the trick.
|> 
|> >BTW, I haven't figured out a practical application yet for any of
|> >this yet.
|> 
|> Audio, and eventually video, conferencing.
|> -- 
|> In-Real-Life: Chris Torek, Lawrence Berkeley Lab CSE/EE (+1 415 486 5427)
|> Berkeley, CA		Domain:	torek@ee.lbl.gov

It's all very neat! But here `play' returns "play: error opening /dev/audio:
Permission denied". And indeed to play sounds here I can only to use
`soundtool'. Any help, please?

Thanks,

Francesco Caserta