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View Full Version : Vdub adding artifacts to encodes?


t0ad
12th May 2002, 10:39
I'm not sure what to make of this problem since i've never seen it anywhere else, but here goes. See this picture.

http://www.theforumisdown.com/uploadfiles/050102/vdubproblem.jpg

what this shows is an encode i took with my MSI GeForce4 ti4400 through s-vid from my directv in uncompressed avi, 29.97 fps. In virtualdub, all i've done is open the uncompressed avi, and skipped ahead to a frame. On the right is the exact same file opened in AviUtl and seeked to about the same frame. Now .. what is up with all the artifacts in virtualdub? It's like its actually ADDING noise and macroblocks to the *uncompressed* avi! I have no idea how to explain this one .. it looks just fine in media player and AviUtl, but in Vdub it looks plain nasty. I've noticed that when i open ANY video file in vdub it looks noticeably worse. After I compress it in vdub, even with uberhigh quality divx settings, it looks just like the preview, very nasty. Encoding it in AviUtl results in waaay better quality.

I've tried different versions of vdub (using 1.4.10 now) but it still opens the file and magically adds artifacts. I capped it via vdub btw. I've uninstalled all of my codecs and reinstalled them all, but the problem is still there. This is a total pain because I have to use vdubs avi splitting to encode in uncompressed avi initially.

I tried using aviutl to splice all the 2 gig avi chunks together and just forget vdub all together, but the pieces somehow dont join together correctly unless i use vdub. theres a couple seconds of black with only audio where they join when i use aviutl.. but NOT in vdub. -_- anyway .. don't know what to make of this, any help is appreciated..

LordDethstar
12th May 2002, 13:38
That's VirtualDub outputting the video in 16-Bit mode for performance reasons. The video is still okay. If it bothers you, go to Options->Preferences and select a different output color depth.

t0ad
12th May 2002, 18:51
..you know, that appears to have fixed it. Don't have the time to test it on new encodes seeing as how i gotta get to work, but the video actually looks like it does in media player now. dunno if it was a bug with vdub or what, but the way that setting was in there it applied itself to the finished products as well, making them all an ugly 16 bit.

Thanks a lot though .. this looks like it worked :D