Re: Choppy Audio

Geoff Rehn (rehn@cleo.murdoch.edu.au)
Mon, 19 Dec 1994 01:41:28 -0500


At 10:35 PM 18/12/94 -0500, Michael Sattler, San Francisco wrote:
>At 11:53 12/18/94, Kenneth J. Malone wrote:
>>
>>We are running Mac IIsi's on a LAN with a 56k internet connection.
>>The audio is very choppy....The sound get worse as more windows are opened.
>
>My gut reaction is: what else is that line being used for? 56 kbps is
>close enough to the approx 32 kbps need of audio alone, that I wonder
>whether a small amount of video signal will be enough to cramp that 32
>kbps. Your comment about the sound getting worse as more windows are
>opened reinforces my total-bandwidth idea.

People still do not seem to be generally aware that CUSM now offers the
16kbps delta-mod encoding for audio. Thus, the 32kbps restriction for audio
is no longer applicable.

Using delta mod at 16kbps, pausing video send, video receive, etc, etc, one
should be able to get good audio at that bandwidth.

Of course, with many open receiving video windows, it is too much to expect
audio to be good.

Try closing off or pausing a few incoming video streams; at the extreme,
stop sending your own video stream and test audio at 16kbps.

Geoff R.

Geoff Rehn
Academic Services Unit Murdoch University Western Australia
voice: (09) 360 6308 fax: (09) 310 4929
rehn@cleo.murdoch.edu.au