Re: Slow video

Mark Goldstein (ae330@lafn.org)
Mon, 10 Mar 1997 13:27:12 -0800


Maybe I wasn't entirely clear. From what I'm told, my video (of me) is
very good, with high kbps and even 1-2 fps. It's the incoming video that
I'm having trouble with. I don't use audio because I know it's a
bandwidth hog. :) The main reason I'm concerned in the first place is the
fact that others are seeing me (and others) at a much better rate than I'm
seeing them, given that we're both connected to the same reflector at the
same time (and not an overloaded ref at that). As an example, I was on a
ref the other night and there were only 3 people on. I was getting
1-3kbps and 0 fps from the one window I had open. The other person
apparently also had that window open and he mentioned he was getting
about 10 kbps and up to 4 fps from it. Hmmmmmm.... And I don't
believe either was on ISDN (I know the sender wasn't).

Mark

>
>Mark;
>
>the "51,200" that you see is the DTE speed or the spped of the modem to PC bus.
>What you really want is the speed that the two modems connect at or modem to
>modem speed. To get this you need to change one of your modems reporting
>parameters (usually ATW? for Hayes command language). Look up th "W" command
>in your modems users guide. You can set it in your dialup networking connectionsince optional modem settings are looked at last by Win95. This will over-ride
>the the default value.
>
>But getting to the cause of your slow video.... it's due to the slow connection
>speed which for you is actually 33.6kbps or less depending on what the two
>modems negotiate at connection time. To get resonable refresh rates you will
>need ISDN (both channels ~128kbps) at a minimum.
>
>But wait...there's less! Don't give up because there are tricks to improve
>your video experience. If your goal is point to point communication where
>the other person is also on a modem you could try this.
>
> Drop your maximum xmission rate down to 10 - 14 kbps. Use the audio
>from a program called "SpeakFreely" (www.fourmilab.ch) and set the audio
>compression to "GSM" and "SIMPLE." This drops your audio bandwidth down to
>to the point where both your video from Cu-Seeme and audio from SpeakFreely
>will fit within your total bandwidth. The advantage of this setup is the
>audio is much more consistant and reliable the Cu-Seeme audio over a narrow
>bandwidth connection.
>
> Having done that your video will still be slow but the audio will
>be perfect. Well,,,,perfect if you can't tell the difference between
>Donald duck and Luciano Pavarotti. It's a far better thing to miss some
>video frames then audio frames.
>
> Other tricks to improve your video are: use dark stationary background;
>don't move more then you hav to; make yourself smaller by positioning the
>camera further away; use side lighting so only half your face is shown. In
>general; the video frame is split up into small squares (8x8 pixels I believe)
>and only the squares that change are sent. Hence; the less the scene changes
>the less the bandwidth and the higher effective frame rate.
>
> Finally; if you run out and buy your own T3 connection you can
>forget about everything I just said. :-)
>
>Warren
>

--
Deja-Moo: The feeling that               \\\//        Pentium Borg: Division
you've heard this bullsh*t before.      -(@ @)-       is futile. You will be
To err is human, to moo bovine.   ---oOO--(_)--OOo--- approximated! 
 Mark Goldstein  ae330@lafn.org  http://www.geocities.com/SiliconValley/1512