View Profile
View Forum Posts
I've noticed that sharp detail/fonts on this DVD I have consistently twitter (I'm viewing it on my mac), and I don't get it. I thought twittering only happened on interlaced displays.
Try StreamFab Downloader and download from Netflix, Amazon, Youtube! Or Try DVDFab and copy Blu-rays! or rip iTunes movies!
+ Reply to Thread
Results 1 to 17 of 17
Thread
-
-
'twittering' = ringing ?
-
My guess is he means flickering .. ??
-
Bouncing up and down by one scan line? That's from a bob deinterlace. Or possibly some other deinterlacer.
Last edited by jagabo; 12th May 2013 at 18:29.
-
There are dots bordering the outside of the letters of text that go up and down, giving the letters a jagged appearance. It's like a chainsaw sort of effect.
Last edited by 90sTV; 12th May 2013 at 21:30.
-
Is it only on colored edge? Not on grayscale edges? That sounds like dot crawl.
http://en.wikipedia.org/wiki/Dot_crawl -
Yeah, I think that's it.
-
It's just a badly made DVD then.
-
So what part of the DVD creating process would likely be responsible for this?
-
If it's truly dot crawl, then likely it was derived from an analog source. Then the source is the problem
-
Formerly 'vaporeon800'
- Apr 2001
- Vancouver, Canada
Picture vs. thousand words.
-
Is this dot crawl?:
http://postimg.org/image/605rqi5h7/ -
Yes. In a video the dots will be crawling, moving.
-
Twittering/Flickering is common on DVDs that were (incorrectly) created with text and/or graphics that are too sharp for interlaced display. This sharpness results in fine one- or two-line segments that stand out because they don't blend in with the rest of the (natural background) image. In a sense, it's a variation of ALIASING. It should have been avoided by using a 1-to-4 line vertical motion blur (or alternately, a Gaussian blur of 1-to-4 pixels isolated in the vertical domain). The result that you are seeing is the fault of the DVD creator(s).
It can be fixed after the fact, using similar anti-aliasing filtering, but there will be some mild resolution loss throughout the image as a result, but at that point it can't be helped.
Scott -
I've been wondering - what kind of source would DVDs with dot crawl likely be transfers from? Since from what I've read Beta SP is component video, and dot crawl is from composite, what kind of tapes would you see dot crawl on? Umatic? VHS? Seems like it would be strange for them to have come from VHS since I didn't think that was used in professional broadcasting unless they were selling it to consumers...unless that's just what the network had lying around.
-
1991 is most likely from a 1" master, possibly D-2.
-
Could be from any of those masters if the digitizing were done via composite (and a not-so-good one at that).
Quote
Visit Homepage
