Re: New version supporting PAL

Jason Williams (streak@ccwf.cc.utexas.edu)
Thu, 5 Mar 1998 09:58:31 -0600 (CST)


On Thu, 5 Mar 1998, Adrian Close wrote:
> This is purely an issue with your capture card, and not really anything to
> do with CU. Your capture card converts the analog video signals to a
> digital data stream.
>
> CU just gets digitised video via hardware driver from the capture card -
> it doesn't know or care what the capture card's input was.

I don't believe this to be true.
>From http://cu-seeme.cornell.edu/V32X/capturecards.html:
A Note on Cameras

Currently, this version of CU-SeeMe only supports NTSC cameras. I
know, the Win16 version did PAL, but PAL support, for both big and
small video will be forthcoming.
--------------------------------------

The version of CU has to change each format from a card into another
format. If this wasn't the case, then ANY capture card using ANY
format would work with the Cornell version.

I don't know the details, but I believe PAL standards have different
resolutions than NTSC, so that also has to be dealt with to get it to
160x120/320x240/etc... I could be off though.

That would lead me to believe that it's a function of the software.
Afterall, the software is what has to convert the video format into
something acceptable to CU. (ie: it has to convert a lot of formats into
what CU uses). I believe DirectX/ActiveX changes this notion, but I don't
really know.

> So yes, effectively CU supports both NTSC and PAL input, and users with
> NTSC and PAL format video input can talk to each other...

If the software supports both NTSC and PAL formats, then communicating
with the opposite format should be transparent.

--
streak@ccwf.cc.utexas.edu    * Jason Williams -- Austin, Tx.  |     |
streak@mail.utexas.edu       * University of Texas at Austin  | ___ |
streak@cs.utexas.edu         * BS Computer Science             \_|_/
*************** http://ccwf.cc.utexas.edu/~streak/ **************|