Audio
Francesco Caserta
caserta at athena.mit.edu
Sat Jun 15 12:43:27 AEST 1991
In article <14083 at dog.ee.lbl.gov>, torek at elf.ee.lbl.gov (Chris Torek) writes:
|> In article <1991Jun7.134254.11485 at citib.com> scairns at citib.com
|> (Scott Cairns) writes:
|> >... The following was suggested by <barmar at 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 at 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
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