avi to anything else switches to B&W??

[matroxg200]

Hello everyone!

I am experiencing a very strange problem converting an avi (mjpeg that I recorded myself) to other formats (I tried VCD, Mpeg1&2 and DivX with LSX and Panasonic but they all give me the same result).
The source avi is ok, the colours are ok from beginning to the end.
When I encoded it though, after a fixed amount of time (it's the same with all the codecs I tried) the playback of the resulting file switches to black&white and remains b/w until the end of the file.
Any idea of what could be happening?
Other avi's don't cause this encoding problem.
(I'm using the latest RRG/G400 drivers on a p3b-f mainboard with the latest driver and Win98)

[dchip]

I recall a lot of posts about this in the past. It is some sort of driver/codec issue. Try using search function in this forum and search words "black & white" (without the quotes) and you'll probably find some answers.

[matroxg200]

Hello again,

Yes, I looked at the threads talking about the black&white problem while encoding but they are threads dated back at end of 1999-beginning of 2000 and then it looked like it was a driver bug which would have been soon corrected.
Someone hinted it might be a bug related to ultradma66-33 hd's but I'm using an ultra2 scsi hd for captures so this kinda prunes the tree of the possible causes.
Now it's end of 2000 and, if it was a driver's bug, the bug is still here.
But if it wasnt a bug..what else could it be since it keeps behaving this way?
The only solution posted then was to replace the matrox hw codec with morgan's or picvideo's one which is not exactly what I wanna do now.

Sorry for the free rant

[LuSiD]

That's exactly what you want to do. Otherwise you'll be fighting corrupted captures as long as you use this hardware.

Save yourself the aggrevation and get the Morgan codec installed. It's an inexpensive solution to a problem that Matrox either can't or won't fix.

Here's a little trick you can use to identify bad captures before you spend 8 hours converting them:
Open a capture using the matrox software and pause the video, then open the file you want to check in media player. The paused video keeps the hardware codec busy, forcing the one in media player to use the software codec (the one used for recompression in other apps). Then scan through the file looking for B&W sections.

[matroxg200]

Hello,

it's easy to see if it switches to B/W by opening the avi in tmpeg encoder, clicking in configure, then advanced and then source frame range and quickly moving the cursor towards the end of the avi.
You can even see the "bad" frame (I never had more than one per file but I must admit I never recorder clips longer than 15-20 mins either)
The fun thing is:
if I move the cursor forward and I pass through the bad frame I usually see two completely scre..ehm.. messed up frames and then all the following ones are BW but if I move backwards from BW frames to colour ones I pass through NO bad frame, ie it simply switches back to colours where there should have been the first bad frame.
An mpeg encoder encoding from the end of file to the beginning might work then