Quantcast PAL60 capture, intermittent greenish tint? - digitalFAQ Forum
  #1  
03-21-2020, 10:50 PM
whysleep whysleep is online now
Free Member
 
Join Date: Mar 2020
Posts: 2
Thanked 0 Times in 0 Posts
Hello,

This is my first post here, and I'm in need of some help.

I've recently purchased an Elgato Video Capture usb device, one that accepts PAL60. I'm still getting the hang of it, so I apologize if this has been answered already, but honestly I couldn't find a similar situation.

I'm using a simple PAL vcr, no tbc. It's connected with composite cables, with a scart adapter on the vcr side. Still, I'm pleased with the results, so far, it gets the job done.

However, when capturing NTSC tapes, in PAL60 format, there's an intermittent, soft greenish tint. I don't think it's Macrovision, at least it doesn't look like it, and I believe the tapes in question are too old for it. This doesn't happen when I connect the vcr to my tv, so I guess that rules out both the vcr and the tapes. It does happen with both Elgato's software and VirtualDub, which I prefer. Naturally this doesn't happen with PAL tapes, only NTSC ones.

Here are a couple of caps, from the same scene, illustrating how this changes from one frame to the next.

Normal:
Normal.png

Green:
You must be logged in to view this content; either login or register for the forum. The attached screen shots, before/after images, photos and graphics are created/posted for the benefit of site members. And you are invited to join our digital media community.


This is especially noticeable in skin tones. In other scenes, with strong reds and oranges, I get purplish horizontal lines, equally intermittent.

Normal:
Green.png

Lines:
You must be logged in to view this content; either login or register for the forum. The attached screen shots, before/after images, photos and graphics are created/posted for the benefit of site members. And you are invited to join our digital media community.


Does anyone have any ideas, maybe some VirtualDub filter...? Is there still hope to make it work with this hardware?
Thanks in advance



Last edited by whysleep; 03-21-2020 at 11:42 PM.
Reply With Quote
Someday, 12:01 PM
admin's Avatar
Ads / Sponsors
 
Join Date: ∞
Posts: 42
Thanks: ∞
Thanked 42 Times in 42 Posts
  #2  
03-22-2020, 02:08 AM
lordsmurf's Avatar
lordsmurf lordsmurf is online now
Site Staff | Video
 
Join Date: Dec 2002
Posts: 8,970
Thanked 1,503 Times in 1,312 Posts
Quote:
Originally Posted by whysleep View Post
I'm using a simple PAL vcr, no tbc.
It's connected with composite cables
I don't think it's Macrovision
Macrovision is anti-copy, and all analog anti-copy are artificial video errors. What you're seeing a classic error due to no TBC in the workflow. So, in a way, it is the same as Macrovision, just not MV specifically.

Composite isn't helping matters.

It's a hardware workflow problem. You need TBC, it's not optional for capturing.

I just linked this for another poster: http://www.digitalFAQ.com/editorials...g-workflow.htm

Especially this part:
Quote:
A basic/minimalist/essential workflow is
  1. the tape player or camera
  2. something that does timing correction and/or frame sync
  3. digital device (computer capture card, DVD recorder, DV capture box/camera)
Again, workflow = sequential steps. The analog signal is played, then corrected/prepped for digital acquisition, and then captured, in that specific order. And the middle TBC step is required, not optional.

- Did my advice help you? Then become a Premium Member and support this site.
- Find television shows, cartoons, DVDs and Blu-ray releases at the TVPast forums.
Reply With Quote
The following users thank lordsmurf for this useful post: whysleep (03-22-2020)
  #3  
03-22-2020, 02:18 AM
whysleep whysleep is online now
Free Member
 
Join Date: Mar 2020
Posts: 2
Thanked 0 Times in 0 Posts
Thanks for your reply.

Yeah, unfortunately, given the tapes I want to capture, getting a tbc is out of the question, I really don't want to spend the money, and I wouldn't even know where to get one, or which one to get.

Like I mentioned, though, when it comes to PAL tapes I'm finding the result pretty satisfactory, so I guess I can consider a tbc relatively optional in that regard, given the circumstances. Unfortunately the same doesn't seem to apply to PAL60...

By the way, and I'm sorry if it's a stupid question, but... composite isn't helping, even though it's all I have, but a scart adapter with S-Video output wouldn't make any difference, would it? Considering the vcr itself doesn't have an S-Video output, and the tape isn't an S-Video one...
Reply With Quote
  #4  
03-24-2020, 07:32 PM
msgohan msgohan is offline
Free Member
 
Join Date: Feb 2011
Location: Vancouver, Canada
Posts: 1,084
Thanked 235 Times in 207 Posts
Using a SCART adapter with S-Video output would actually be worse in this case. An additional crosstalk artifact would be added.

In addition to the color issues, we can see lack of line TBC in the screenshots posted. The borders of the image should be straight; yours are bent and wavy. Everything within the image will also be affected, but in these still shots without any columns it isn't obvious.

I suggest hunting for info on which DVD recorders can function decently as passthrough TBC while supporting PAL60: https://forum.videohelp.com/threads/...=1#post2574731
Reply With Quote
  #5  
03-24-2020, 08:51 PM
hodgey hodgey is offline
Free Member
 
Join Date: Dec 2017
Location: Norway
Posts: 670
Thanked 149 Times in 127 Posts
Quote:
Originally Posted by whysleep View Post
By the way, and I'm sorry if it's a stupid question, but... composite isn't helping, even though it's all I have, but a scart adapter with S-Video output wouldn't make any difference, would it? Considering the vcr itself doesn't have an S-Video output, and the tape isn't an S-Video one...
That will only help if the VCR has S-Video output over scart. S-Video out is pretty only found on SVHS VCRs and certain DVD-Recorder combos that digitize the video internally. (Pretty much all DVD/VCR combo units have S-Video output, but only for the DVD portion.) It's easy to be confused by SCART connectors, since the same connector can provide different functionality depending on the device. Even more so with S-Video over SCART as it's a bit of a hack that has to be set manually by both devices connected together. A normal VHS vcr will only have composite + audio in/out from the VCR itself over a SCART connector (and in some cases maybe AV.link/control stuff but that's not relevant for capturing). They will usually be able to pass through other signals like RGB from the scart input connector to the scart output connector though.

The lines you are seeing is leftover color signal that the capture device has not been able to filter out. I'm guessing the Elgato uses the conexant chips similar to the Diamond VC500 and hauppauge capture dongles, which are not very good at separating the color and brigtness from a composite signal.

I second msgohans suggestion.
Reply With Quote
Reply




Similar Threads
Thread Thread Starter Forum Replies Last Post
Panasonic AG-4700 weird intermittent picture issue? rocky72 Video Hardware Repair 8 11-26-2018 06:51 AM
Way to automatically control intermittent overexposure issues? stevevid Restore, Filter, Improve Quality 13 09-14-2018 09:15 PM
BVP4+ intermittent signal issues (c/s switch?) bilditup1 Restore, Filter, Improve Quality 13 09-22-2015 04:12 PM
How to remove redness from picture - Fix color cast or tint problem admin Photo Processing, Scanning & Printing 1 01-23-2011 05:44 PM

Thread Tools



 
All times are GMT -5. The time now is 11:55 AM