View Full Version : Chroma Flare Removal
matrixtj
17th October 2016, 08:03
Hi Everyone
I'm trying to get rid of unusual chroma problems from a 34 year old video tape. Every second or two (perhaps more sometimes) the colors seems to flare at the entire frame and in most cases, most of the colors behind the flares are lost. I use Cnr2 to somehow reduce the flare quite a bit but still the flare is present. When the frame is converted to grey scale, the flares are gone (as well as the colors). I'm also not sure how to bring back the colors to the frame after the flares are gone. Another solution I though of was to use both Cnr2 and Ccd to more effectively reduce the flare, but I loose more of the original colors that's left due to colorspace conversion. Sadly, I tried to re-record the video tape with a TBC, but after the first recording, the tape quickly deteriorated. The video tape also has some other artifacts such as dot crawl and color flickering. Here's a short clip of a show intro.
https://youtu.be/fchXm1qddSQ
LemMotlow
17th October 2016, 21:41
That attachment has been re-encoded and otherwise degraded by UTube. You apparently have DGindex, so why not use it to make an unprocessed short clip we can work with? YouTube sucks.
StainlessS
17th October 2016, 23:08
As per LemMotlow suggestion:
In DGIndex, mark a section of about 20 -> 30 secs with movement, using the Start '[' and End ']' buttons.
Then select File Menu, "Save Project and Demux Video".
Upload the result m2v to eg MediaFire or SendSpace.
Or just cut using some other cutter if not DGIndex cuttable file.
matrixtj
18th October 2016, 03:28
Alright. I've re-uploaded the video file in google drive. The original clip is in m2v but the processed video (the avi file) is best to leave as it is, otherwise the time stamps get screwed and you wouldn't be able to sync throughout the video.
Original video: https://drive.google.com/file/d/0B9u3xDRrptR0cnk4OTk4OWFDOWs/view?usp=sharing
Processed video: https://drive.google.com/file/d/0B9u3xDRrptR0bzg3N21wcVMzbmc/view?usp=sharing
StainlessS
18th October 2016, 04:41
The experts on-site are only interested in seeing the unprocessed clip, m2v cut in DGIndex would be just fine, AVI not necessary.
(Just for future reference, save you uploading something that nobody is gonna look at).
matrixtj
18th October 2016, 08:17
The original video is the unprocessed video in m2v, the processed one is the video generated by Avisynth. Both videos are 28 seconds. I just wasn't quite sure because I am a newbie.
matrixtj
18th October 2016, 15:13
Here's the 'shorter' unprocessed clip.
https://drive.google.com/file/d/0B9u3xDRrptR0RjFhSDhXVTY1TVE/view?usp=sharing
LemMotlow
19th October 2016, 03:20
You say your problem is "chroma flare"? Whether you're new to video work or not, surely your eyes are better than that. It's bad tape, played with a bad player, horrible vertical jitter and line timing errors with no line tbc, serious mistracking, , etc., etc., etc., all of it worsened by recording to a lossy codec. If you no longer have the tape and can't even get a decent VCR, I'm afraid you're stuck with garbage from too many previous mistakes.
:(
matrixtj
19th October 2016, 12:15
When I recorded the video tape the second time with a standalone TBC (bought it recently), the audio wasn't as good as in the previous recording and it had more errors and physical damage. The TBC did get rid of the vertical lines, made the picture still and eliminate color flickering, but it has a lot of ghosting and there is something weird at the top of some frames. I still have the tape but I don't think it's gonna be any better. If you have any suggestions to make any improvements (even minor), I'll be satisfied.
LemMotlow
19th October 2016, 12:39
I mentioned a line-level tbc, not a standalone frame-level tbc. No one knows where this tape came from or what player or capture device was used for the recording. The video has field or frame blending which smears and distorts color to begin with and can't be repaired. It has lossy compression artifacts that won't go away. More processing, even if you had filters that could address those problems, will only make it worse.
matrixtj
19th October 2016, 14:07
Alright. I'll try to buy an another VCR that has an inline TBC and re-record the tape. I hope the everything is going to be fine.
Thanks for replying.
LemMotlow
19th October 2016, 18:08
Alright. I'll try to buy an another VCR that has an inline TBC and re-record the tape. The proper term isn't "inline", it's line level". For short, these are often called "line" tbc's. A line tbc corrects bad scanline timing within frames, combats vertical jitter and "wiggles" on angular lines and borders (look at the notches and wiggles in the side borders of your video sample). A "frame" tbc, usually an external unit, corrects frame sync timing but has no effect on scanlines within individual frames. For bad tapes a frame tbc prevents dropped frames, bad audio sync, and often frame hops. They are two different types of tbc.
A vcr with builtin line tbc will cost a pretty penny, and finding one that hasn't been burned up by pros or hubbyists is difficult. You might be better off finding a consumer vcr that's still in decent shape that can track a tape better than the one you're using now. For line tbc you can find a used Panasonic DVD recorder that can be used as a line tbc "pass-thru" device between the vcr and the capture device. http://forum.videohelp.com/threads/319420-Who-uses-a-DVD-recorder-as-a-line-TBC-and-what-do-you-use .
You haven't revealed any history of this tape. It looks like a multi-generational tape to me, or at least a video that's gone through previous processing. If it's a tape dupe, you won't get rid of those line sync errors--they're a permanent part of a tape duped to another tape without a line tbc.
If you expect to do any repair or restoration work, never copy to lossy codecs. If you don't know what lossless capture is, you need to find out. MPEG (DVD), h.264, etc. are not designed for repair or edits. As it looks from here, that tape would be a very rough restoration project. Good luck. I'm not holding out much hope, but do what you can with a better player and capture device. IF there's no improvcement you can always sell the hardware -- people everywhere are dying to get their hands on good players and capture cards.
matrixtj
20th October 2016, 14:48
I'll do some know the history of the tape. The tape has been re-recorded between 1982 and 1984. The tape is an Australian Palsonic E-180 Hi Image and definitely not a very high grade video tape. How the tape looks like:
http://goughlui.com/the-vhs-corner/vhs-cassette-library/palsonic-hi/
I'll definitely buy a better capture card, get better software for capture and a DVD recorder with a line TBC. That will take a while.
I now understand the errors I've got and the difference between line and full frame TBC.
Thanks again.
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