CUSeeMe Audio -- where are we going?

Dennis J. Streveler (strev@mobius.net)
Sun, 25 Feb 1996 18:43:46 -0700


SFO DJS 96/02/25 11.17

Hello!

I have now been an avid user and experimenter with CUSeeMe for several
weeks. It appears one deep dark secret which no one seems to want to
discuss: CUSeeMe's weakest point is its audio capabilities on relatively
constrained-bandwidth Internet connections (28.8k modem connections up to
128k ISDN connections).

Upon some reflection, it is interesting to note that AUDIO becomes more a
problem than VIDEO on TCP/IP networks such as the Internet. If you get
lagged, if the network becomes overloaded, with VIDEO you can merely throw
away a frame or two, or not accept new frames from the transmitter. With
AUDIO, connected speech requires a smooth delivery of packets and a
relatively constant available bandwidth in order to delivery PLEASANT
speech. I make the distinction between INTELLIGIBLE speech (ham radio
operators surely must be aware of this notion) and PLEASANT, COMFORTABLE
speech, which by its nature is continuous, full-duplex and relatively
consistent in audio spectrum quality. CUSeeMe fails to deliver the latter.

Here are some specific questions:

1) Is the quality of audio transmission a function of PLATFORM or CLIENT
these days? Does Mac-PPC do a great deal better job in digitizing speech
than Mac-68k? Does Wintel (with reasonable soundcard) do better than
Mac-PPC? (My unscientific observation is that Mac-68k appears to be the
WORST of the three, and Wintel the best.)

2) Are there new (better) speech compression algorithms out there which is
going to alleviate this problem to some extent SOON?

3) Rather than play black magic with the CUSeeMe transmission settings,
surely there must be a document which says: "if it appears that you are
getting xxkbps thruput, then your transmission setting should be xx,xx,xx."
It would seem however, that perhaps there should be NO settings at all, and
CUSeeMe itself should make those determinations on the fly!

Viable "videoconferencing" using CUSeeMe requires a fluid, usable audio
capability. I can put up with jerky pictures. But I am surprised that the
developers added color and all those neat things to CUSeeMe when the audio
capability of CUSeeMe appears largely unusable!

One final remark, it amazes me that White Pine allows its "test reflector"
to take on the loads which it does. Many times the reflector comes to
complete gridlock, refusing to send any new (useable) video, and nobody
DARES to try sending audio! Is this a way to promote the viability of
CUSeeMe?? I think not.

Regards,
Dennis

------------------------------------
Dennis J. Streveler, Ph.D.
Systems Consultant
San Francisco, California, USA
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CIS: 71036,1645
Internet: strev@mobius.net
CUSeeMe: strev.mobius.net
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My job? To send the appropriate electrons hurtling around the globe.