CU-SeeMe Bugs and Tips

NETWORK is the bug word of the day! Most of the new problems mailed to me and asked about online end up being network related. Check out my Network page for the latest info. A lot has changed in CU-SeeMe since this page was the primary focus of this website. Now it's just a small part. I keep it as some have directly linked to it and search engines have it as well. I 'll update it from time to time but please check elsewhere on this site for what your looking for FIRST.

Proper Etiquette

Feel free to speak your mind or to display whatever you wish to display, but please show respect for others. Try not to be abusive or rude to others. Openly harassing other users will generally get you hated/banned at least or at most force those person(s) from CU. This would be a loss for all of us! Guys please remember to think with the brain on top of your shoulders, the ladies are not on the internet as your personal sex objects!

DC - Direct Connection

Also known as 1 on 1. This is where two users connect for private conversation. The IP is typed directly in the Phone Book dialog "Address" field without clicking on a reflector. Then click on connect. It is considered extremely rude to attempt a DC without asking permission FIRST !! Video can be set differently in this case to a larger size (320x240), higher quality (30-40%) and higher Tx/Rx rates (Tx 30 Kbps with 33.6/56 K modem) to support a more NetMeeting like connection. Audio is a lot better on a DC as well.

  • Camera Quits Functioning in CU-SeeMe after a short time.
  • What to do if you get the error: "Your IP address is incorrect, restart CU-SeeMe..."
  • A very good tip for White Pine Lockups and system optimization. This is a chronic problem with White Pine CU-SeeMe as the program uses virtual memory for video frame storage.
  • How to disassemble a Connectix B&W Quickcam

    When I try to open CU-SeeMe it says "...the trial period for the add-on multimedia codec expired......"

    Users of this codec will, after a time, get an error message that says "...the trial period for the add-on multimedia codec expired......" This error message means the Shareware trial period is over. Either a replacement codec from a different vendor or a newer version of the same codec has to be installed. See the Codec Information page for more details.


    Some Cornell CU-SeeMe users have reported that it took 2 or 3 times of making these changes before it "took" and the error went away. Please keep in mind that as long as you are getting that error you cannot connect to a reflector since you are not actually sending out video. You MUST re-start the CU program before you can connect to a reflector. If this error persists it is more than likely the camera is NOT supported by the Cornell version of CU-SeeMe (your camera is not providing RGB video in MS Video format). You may need to use the White Pine Enhanced CU-SeeMe instead.

    Most RGB cameras will work with both the Cornell and White Pine versions of CU-SeeME. The cameras that only output IYUV video streams will only work (un aided) with the White Pine version. An add on program called Softcam from Luminositi has allowed some cameras to work with the Cornell version though.

    If you receive this error the fix is twofold:

       1) Verifying that the M-JPEG codec is selected under View, Preferences, Video Tab Codec section.

       2) verify Millions (24 bit) colors is set under View, Preferences, Video Tab, Video Format.     Color section.

       3) Change the sending video Size from QCIF (the default for most USB cameras ) to 160 x 120. Hit Apply and then OK. Shut down and restart the program.

    Indeo codec --- This guy has a picture of a paper note on camera!

    Actually this is a symptom of the Indeo codec being in use (instead of the M-JPEG codec) by the sender. Below are two pictures that show how the video opening screens differ. Once the video comes in a person usually appears.

    M-JPEG codec    Intel Indeo codec

    The Intel Indeo version 5.0 codec can look quite good at quality settings of 25-30% ---- the M-JPEG is superior at quality settings of 15-25% only because the frame size is smaller, also giving a faster frame rate. The Intel Indeo version 3.2 codec video looks like it's being filtered by a vertically lined etched glass, the version 5.0 codec has a much less severe line problem and to many is indistinguishable from the M-JPEG image.

    M-JPEG codec
    Intel Indeo 3.2 codec

    Intel Smart Video Recorder

    Users have reported that the ISVR works with White Pine Software's Enhanced CU-SeeMe. Intel Technical Support has verified that both the ISVR and the ISVR PRO works with Enhanced CU-SeeMe. Not sure if the free Cornell version of CU-SeeMe works with these cameras.

    To configure White Pine Enhanced CU-SeeMe:

    1) Click on Edit; click on Preferences
    2) Select the Video tab
    3) Under the Capture Device box, click on FORMAT
    4) Set the Video Compression Method to Intel Indeo(TM) RAW Video

    where did my typed text go???

    Chat loss is something that is very frustrating effect that varies from reflector to reflector. Many times it relates to the communications settings being incorrect, so it's a "curable bug". Setting the "Maximum Transmission Rate" above 18 Kbps is most often the cause. For a verbose "techie" explanation go here. Sometimes reconnecting to the reflector will produce a better (more chat) connection.

    Have you ever experienced an apparent DC??

    In article <52ran3$,
    Prince Myshkin wrote:
    > Another bug I have encountered is that the MOD will come up, then the ref will
    > not respond. To make it respond, I have to close CU altogether, then reconnect.
    Yep..another PC client bug :) This one seems to happen only when you try connecting to an empty reflector. It shows the MOTD, then times are actually connected to the ref.. the client just doesn't know it...if someone connects to the reflector while you waited and timed out, it will appear they DC'd to you. when actually yall are both on the's a weird bug. Let's hope the new Enhanced version 2.1 fixes some of these bugs. * Jason Williams -- Austin, Tx.

    "Why does my chat follow me from the previous reflector?"

    AKA Chat Drag or Chat Spew. "...the original authors of the Talk and Chat facilities chose to keep the message data around for 15 seconds after the message has been sent. After 15 seconds, the messages are purged ...." (See the fifth paragraph below). The cure is to wait 15 seconds between disconnecting from the "old" reflector and then connecting to the "new" reflector. Some people have said closing the chat window in between reflector connections also does this, but it's not clear if the time delay in closing/re-opening that "fixes" it or the closure itself.

    Typing in chat - undocumented keystrokes

    The Edit menu doesn't work for copy and paste. Instead you must first select the text in the chat window and then copy it by typing Control-C. To paste text in chat select and copy the text from elsewhere and then place the cursor in the chat window. Then hit Control V. Edit the text if needed and press enter to send it out. CTL-ENTER can be used to create separation in unsent text.

    Chat loss "techie" explanation

    Date: Mon, 15 Jul 1996 16:31:56 -0400
    Subject: Re: where'd my typed text go???

    There has been much discussion, some of it recently, about the reliability (or lack thereof) in CU-SeeMe's "Talk" or "Chat" facility. Perhaps a bit of background information might be useful or interesting (or not).

    Talk and Chat are applications of the "Auxiliary Data Transport" facility within CU-SeeMe, a facility that provides "pretty good reliability" for one-to-many and one-to-one data transfer. This facility is separate from, and runs in parallel with, CU-SeeMe's normal video and audio streams. All of these streams use UDP, an "unreliable" transport protocol.

    The Aux Data Transporter includes a series of facilities to provide error detection and correction; the most common error is the "dropped packet", something that can occur at any time with UDP, but something that is probably much more likely to happen in networks involving links of greatly different speeds. A high-speed stream sent to a low-speed receiver, for example, is likely to suffer quite a few "dropped packets".

    In order for the Aux Data Transporter to effect its error recovery processes, it must have the data available to re-send upon request. It is the responsibility of an "Aux Data Application" such as Chat to keep the data around for a long enough period of time for the error recovery processes to be successful. Given that the error recovery packets and the re-tries may themselves get dropped, you can appreciate that the problem is not an easy one to solve.

    For reasons that have never been entirely clear to me, the original authors of the Talk and Chat facilities chose to keep the message data around for 15 seconds after the message has been sent. After 15 seconds, the messages are purged and the Aux Data Transporter can no longer re-send the messages. I would have preferred a longer life-span, particularly since Chat messages are tiny.

    As a part of our continuing (if slow) efforts to improve CU-SeeMe, we will probably be doing several things to try to increase the chances that Chat messages will get through. We will probably increase the message life-span. We may increase the rapidity with which the Aux Data error recovery actions take place, although this is a two-edged sword -- if we send out more "overhead" packets to provide better error recovery, we may end up over-loading certain network links even more, causing additional errors.

    One other detail -- Chat messages currently get only 10% of the available data stream. CU-SeeMe's internal bandwidth management routines will limit each type of stream to a specified fraction of the whole. We may consider increasing the portion available to Chat messages, although that, too, can result in other problems. If you are "chatting" *and* moving around and speaking (or, heaven forbid -- playing music!), then your audio and video will take up almost all of your available bandwidth, making Chat messages even more likely to get dropped.

    When you are trying to put 10 pounds into a 5-pound bag, it usually makes little difference how you divide up the available capacity -- it is simply not enough. For folks who really prefer to "Chat" with others, perhaps a real Chat facility would be a better choice. (Meant seriously and not as a "nastigram"!) ;-)

    Larry Chace (

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    Last updated Tuesday, March 05, 2002 4:09:13 PM