Problem with correcting hue on older VHS tapes.

[spudhalvorson]

Greetings all - I searched the forums, but couldn't FIND the solution I was looking for. I would be grateful to anyone who redirects me.

I am restoring a number of different mediums. For my VHS transfers I use a JVC HR-S9911U. Whenever possible, I run VHS transfers through my Sony HVR-M25U MiniDV and record out on firewire through my PC. The below video was captured in this way, but a separate capture using a S-video Elgato resulted in the same effect.

I have a few tapes from the early 1980s, which I know where recorded using a camcorder that ran a heavy cable back to a shoulder unit assembly with a VHS machine. Presumably, some of these videos struggled with the provided power, and there were intermittent problems in signal delivery.

I have shortened this attached video to 6:30 for reference (https://drive.google.com/file/d/1IYc...ew?usp=sharing). I have the video in an uncompressed file format also.

In the video at the 20 second mark the inside scene is overly magenta, but then corrects to a better (albeit faded) balance at the :58 mark. At 2:07 scenes in the kitchen are slightly yellow, but color is snapped back to normal outside at 3:16. At 4:45 the tint goes supremely wacky to a deep green, but then corrects back by 6:08.

I don't know how to implement some of the coding scripts for adjustment in VirtualDub, but I already use that program a lot. I wouldn't expect an easy one-pass solution this, and am willing to chunk the video in separate parts, color correct as per separate needs, and then re-amalgamate into a finished video.

The video only has so much resolution to start with, but I greatly would like to know how I might address these more-sensitive instances to make them look better.

*Due to the size of uncompressed, .avi files, I would love to find a good compression codec to use. Unfortunately, my experience with Lagarthic has resulted in skewed hue/tint ruining the video. Any tips for lossless compression (outside of lossy mp4/mkv) would be greatly appreciated. In time I would expect to put these files into an AV1 container, but we're not there yet.

*Yes - I know there are some aspects of jigger intermittently throughout the video, but outside of my standard TBC, I'm not sure there is much to do about that.

Thanks!

[timtape]

Quote:

Originally Posted by spudhalvorson

...In the video at the 20 second mark the inside scene is overly magenta, but then corrects to a better (albeit faded) balance at the :58 mark. At 2:07 scenes in the kitchen are slightly yellow, but color is snapped back to normal outside at 3:16. At 4:45 the tint goes supremely wacky to a deep green, but then corrects back by 6:08...

Welcome to the forum. Cameras are more sensitive to lighting color changes than is the human eye. The magenta hue inside the sitting room is probably the lighting in that room. Similarly with the yellow/green hue in the kitchen, possibly due to flourescent lighting. The video camera was probably set for outdoor sunlit color balance. Given the lack of strong shadows, the outdoor scene appears to be shot on a somewhat cloudy day, probably explaining the better color but slight bluish cast.

Others will comment on the green cast appearing on the outdoor scene.

The audio has a muffled sound probably due to a small "azimuth" misalignment of your deck to the recorded tape. The giveaway is a small improvement at camera edit points as the playback alignment momentarily improves (eg: 00:23 and 01:13) and the woman's voice becomes momentarily a little clearer but then reverts to the previously more muffled sound.

There is also a constant high toned whistling in the audio. Since it doesnt change at the camera edit points like the voices do, it is probably not on the tape but has been introduced by the playback VCR. This occurs with some VCR's even though they can have excellent picture playback.

[timtape]

To add, I see what you mean about the early overly magenta look seeming to correct itself. The early magenta cast seems to be more than just the room lighting as early on it's also magenta outside the room, seen through the large glass door.

[spudhalvorson]

Quote:

Originally Posted by timtape

Welcome to the forum. Cameras are more sensitive to lighting color changes than is the human eye. The magenta hue inside the sitting room is probably the lighting in that room. Similarly with the yellow/green hue in the kitchen, possibly due to flourescent lighting. The video camera was probably set for outdoor sunlit color balance. Given the lack of strong shadows, the outdoor scene appears to be shot on a somewhat cloudy day, probably explaining the better color but slight bluish cast.

Others will comment on the green cast appearing on the outdoor scene.

The audio has a muffled sound probably due to a small "azimuth" misalignment of your deck to the recorded tape. The giveaway is a small improvement at camera edit points as the playback alignment momentarily improves (eg: 00:23 and 01:13) and the woman's voice becomes momentarily a little clearer but then reverts to the previously more muffled sound.

There is also a constant high toned whistling in the audio. Since it doesnt change at the camera edit points like the voices do, it is probably not on the tape but has been introduced by the playback VCR. This occurs with some VCR's even though they can have excellent picture playback.

I would agree that especially the older cameras (and this was from a very old consumer VHS capture camera) could contribute to lighting changes. However, as I mentioned (at least in the first sence), the color corrects in the same scene away from the magenta, albeit not in the later kitchen scene.

Notably, while the audio is not perfect - there is not whirring on my original avi file; somehow this was introduced when I created an .mp4 for sharing on the forum - I used OpenShot video editor for this ~ I wasn't sure how to save to a different file type in VirtualDub.

[traal]

I have a home video with the same problem. Unfortunately, it's a copy and the original is long lost, so it's possible that the process of copying introduced the problem which is now baked in. Is yours a copy also?

I'd like to think that capturing the original tape through a proper TBC would fix the problem, but someone with more experience would know for sure.

Otherwise it's going to be scene by scene color correction which is a pain.

[timtape]

Re the magenta hue in the first shot , possibly the camera used a tube sensor as the early ones did, and at first it hadn't quite warmed up and stabilized in color.

[spudhalvorson]

Quote:

Originally Posted by traal

I have a home video with the same problem. Unfortunately, it's a copy and the original is long lost, so it's possible that the process of copying introduced the problem which is now baked in. Is yours a copy also?
I'd like to think that capturing the original tape through a proper TBC would fix the problem, but someone with more experience would know for sure. Otherwise it's going to be scene by scene color correction which is a pain.

I believe my tape (still on hand) is the original copy, but I believe the only way to correct is scene by scene - which I am more than willing to do, I just need some guidance. The sound is fine on the original master to avi., and the minor glitches throughout the captured event are tolerable - I don't believe a better TBC machine will correct those, and my own machine is a pretty good one. I also doubt better TBC will correct the skewed color sequences, but I could be wrong on that.

[spudhalvorson]

Quote:

Originally Posted by timtape

To add, I see what you mean about the early overly magenta look seeming to correct itself. The early magenta cast seems to be more than just the room lighting as early on it's also magenta outside the room, seen through the large glass door.

Yes, except the entire start sequence was longer (clipped for the sake of illustration). After a minute or so the camera focused on the two elderly subjects, and remained magenta, then suddely, the color stabilized. As another commenter mentioned, this could be a warm-up and stabilization factor with the earlier tube capture camera.

[timtape]

Quote:

Originally Posted by spudhalvorson

...*Yes - I know there are some aspects of jigger intermittently throughout the video, but outside of my standard TBC, I'm not sure there is much to do about that.

Thanks!

Yes I noticed the horizontal jittering. Are you sure the tape path is very clean? The first thing I would do as a technician is inspect and if needed thoroughly clean the VCR's tape path and ensure the machine is in very good condition mechanically. A TBC can only do so much. It relies on the VCR itself having a minimum level of mechanical time base stability. Even small bits of sticky dirt on the spinning drum can mess with time base stability.

Quote:

Originally Posted by spudhalvorson

Notably, while the audio is not perfect - there is not whirring on my original avi file; somehow this was introduced when I created an .mp4 for sharing on the forum

I dont understand how that would be possible. If you recheck the avi file audio I think you'll find the tones are there in the avi (the worst ones are at about 7kHz and 10kHz), if anything a little louder than in the mp4.

[themaster1]

I think your a good client for this kind of plugin: https://www.youtube.com/watch?v=vWcoGuw3Z_I
assuming you want to fix all these frame quickly/efficiently. An avisynth pre process might be best