CU-SeeMe Video Information Page
Color Quality Setting
Incorrectly setting the Video Color Quality % too high can cause others to not be able to see your video. People in the reflector conference may see your video as black. Only after waiting serveral minutes for it to open can they see you. They also may give up before this happens or accuse you (unknowingly) of "sending black video"!
The defacto codec standard on the internet, M-JPEG, involves a tradeoff of image clarity and how quickly the image is seen to update on the remote end. A Quality setting of 20% is recommended for almost all reflectors.
Color Quality Setting - Cornell 1.0
The Cornell CU-SeeMe Quality slider control does not have a quality % label. Use these graphics below as a guide. The right picture is the slider aligned with the Y in Quality. Some people prefer to set the slider between the Q and u (left picture) of the Color Quality label. Setting the slider between the Q and u is a less preferred setting. This is right at the edge of where the video begins to have a pronounced square (alligator skin) artifact overlaid upon it (see left image below). Somewhere between these two point is what most people use.
|slider between the Q and u
Color Quality Setting - White Pine 2.1.1 and 2.1.2
White Pine Enhanced CU-SeeMe has a Quality setting that gives % readout. Set the Compression by going to the menu item Edit, then click Preferences, and finally select the Video tab. Make sure the M-JPEG codec is selected as the "compression codec" and then set the Quality slider to 20%
Color Quality Setting - White Pine 3.x.x
White Pine Enhanced CU-SeeMe has a Compression setting that gives % readout. Set Compression by first clicking the Test Setup button.
Then on the Test Setup tab make sure the M-JPEG codec is selected in the "Codec"" pull-down and the Compression slider to 20%
Video breakup - also known as too many video windows open
Trying to view more than the practical amount of video windows is many times the cause. This forces the reflector to slow all of the windows you have open. The Communications Rates page has the maximum recommended number of windows that can be opened based on the modem's connection speed.
Lets say for example your maximum receive is set to 30 Kbps. Also lets say that all users on this reflector are sending at 15 Kbps.
Open two windows. The Actual Receive is now reported as 30 Kbps. (15 Kbps + 15 Kbps = 30 Kbps). All OK so far!
Now open 2 more videos for a total of 4 videos.
Now the Actual Receive reported could be (15 Kbps + 15 Kbps + 15 Kbps + 15 Kbps) = 60 Kbps but instead it stays at 30 kbps. Why?
Well, since your Maximum Receive is set to 30 Kbps the reflector adjusts downward all videos rate to achieve a total Maximum Receive rate of 30 Kbps.
So what happens now? All video's become much choppier, break up, some or all freeze and newly opened windows never change from black to an image.
This is because they are now at 1/2 of the rate they had been at when only two were open.
The cure is to either not open as many videos or establish a correct Maximum Receive Rate. Go here for more information on Maximum Receive Rate Setup.
Video breakup - Cornell version 1..x
I strongly suggest turning off automatic opening of remote video windows. Do this by clearing the Open Video Windows Automatically check box at Edit, Preferences, Video Tab, Options section.
Video breakup-White Pine Enhanced version 3.x.x
I strongly suggest turning off automatic opening of remote video windows. Do this by clearing the Auto-open new participants check box at Edit, Customise..., General Tab, General section.
Video breakup - White Pine Enhanced version 2.1.x
White Pine Enhanced CU-SeeMe v2.1.x does not turn off the flow of video from the reflector of video-windows that you closed. The only way to turn off this video flow is to use the "close-all-windows" command/button (closed eye on the button bar). This is a longstanding bug that causes the majority of complaints about bad/broken video with this version. When the flow of these videos are still present it causes the same problems that having too many video windows open. Video slows, becomes choppier and motion gets jerky. In extreme cases previously opened windows will "freeze" and the just opened video window will remain black.
I strongly suggest turning off auto-open of remote video windows which will help immensely. Do this by clearing the Open and check box at Edit, Preferences, Conferencing tab, Remote Video Windows section. See the picture below.
NOTE: The Close All button usually has to be hit multiple times to kill all of the video streams. Watch your local video window to see the actual
Receiving: rate drop as you hit the button. You WILL have to hit it MANY times and wait a while, be patient!!
Video breakup-B/W video "pixelation" fixes
This more of a bug with White Pine 2.1.x than Cornell CU-SeeMe software. B/W video when it initially comes up has many grey areas around the image where no information from the reflector has been received yet. Seen in the left image below. No fix for that, sorry! Also older Parallel port B/W cameras have much choppier video than a capture card or USB camera. Please don't complain to the user that their video is bad, as there is nothing they can do, and they know already of what your seeing!! There is no adjustment to minimize this for the viewer but sometimes the sender by sending too fast increases losses and makes the video choppier.
The right hand window shows a curable video distortion. When using White Pine CU-SeeMe 2.x.x. most times it can be fixed by clicking on the individual's video window right most button (Info) a few times. In severe cases it's caused by too high a sending rate (Maximum Transmit Rate) causing excessive packet loss in the uplink to the reflector.
Back to Hoople's Home Page
Comments? Send them to Hoople <email@example.com>
All contents © 1997-2002 by Hoople
Last modified Thursday, December 16, 1999 6:09:32 PM