Hybrid input scan type, bottom field first?
 

Hi there. I've noticed that all of my VirtualDub-captured AVI video files, when plopped into Hybrid for encoding, are detected as being interlaced "bottom field first."

I understand that virtually everything should be top field first except for DV formats. So I'm wondering if I have a setting wrong in VirtualDub or something? When I deinterlace my video, it looks pretty decent, but sometimes certain types of on-screen graphics don't look *quite* right, compared to when the tape is viewed on a CRT. And when I try to use "Bob," I get a weird field-swapping effect that is noticeable when certain graphics are shown on-screen (I can upload samples if it's helpful). I assume this is because the fields are being deinterlaced in the wrong order... ? I try selecting " Overwrite input scan type to: Top field first," but when I'm Bobbing, the fields still seem to playback kinda goofy after deinterlacing.


I'm not sure what information from my setup will be useful in assisting me in figuring this out... So here are a few bits of info, if it means anything to anyone:

I'm using a JVC HR-S7900U VCR to capture video in VirtualDub 1.9.11 via GV-USB2 cable.
Video format settings in VDub are 720x480 YUY2.
Codec is Huffyuv v2.1.1 -CCESP Patch v0.2.2

I'm sure those particular details are all completely irrelevant to this, but I'm not yet sure what other information to offer, and didn't want to make a minimal-effort post asking for help. :laugh:

Thanks for any suggestions!

Nothing is detected, as AVI lacks flags for interlace. Hybrid just defaults to bottom.

As in it looks jittery when the analog (not DV) source is deinterlaced to top field first, and smooth when the analog source is deinterlaced to bottom field first?

Had that happen before where those settings were seemingly swapped, a reinstall of Hybrid fixed that issue for me.

To make sure your deinterlace works correctly, confirm that in VirtualDub's Capture Pin dialog that you also set your Frame Rate to 27.970. That may sound counter intuitive for material you'll eventually render out to a progressive 59.94 FPS, but that's the correct capture setting. Any other frame rate will predictably cause issues.

Note: If you have your Capture Pin set to 720x480 by 29.970 FPS, then every time you open on the Capture Pin settings, VirtualDub resets it to something else. But if you set it correctly and close it, your settings will be used.

VirtualDub usually just drops 29.97 frames, unable to capture 59.94 from the source since it doesn't exist. I've never seen it actually capture 59.94.

I get a weird field-swapping effect that is noticeable when certain graphics are shown[/QUOTE]

On the HR-S7900U - open your menu. Go to FUNCTION SET. Scroll down until you hit the second page. Check the VIDEO STABILIZER - set that to OFF (see attached photo).

From what I can tell, when the VCR detects a solid graphic on screen, it knocks the output down to 240p(?). Shut this off and see if things improve. Once you shut it off, you may notice the effect lingers for a few seconds, but will go away.

Attachment 18598[QUOTE]

I can't say for sure what's happening but the few times I failed to set the capture pin to the proper frame rate, it's jacked up my capture (in VirtualDub2).

Thanks! I checked my settings, and the Video Stabilizer feature was already set to Off. But your post prompted me to look up the manual and do a little reviewing, which I haven't done for awhile. Thanks!

Also, since you also own one of these VCRs, perhaps you can help me with something else - sometimes (somewhat frequently, actually) when I'm playing an older tape that isn't in the best condition (or if there's at least an area on the tape that isn't in the best condition) the VCR puts out a rapid, rhythmic pulsing sound. Like an electronic synth bass drum pounding in a fast, even rhythm.

I've always sort of assumed it's going through some sort of auto-tracking process or something... but often the picture looks fine, and it'll still make this noise. And I'm fairly certain I have the auto-tracking feature turned off. Is this anything you're familiar with? I'm hoping it's not a symptom of something wearing out in the VCR... :confused2:

I don't own that exact model but I have two other JVCs, and tested that Video Stabilizer several times, always with the same results - it whacked vertical resolution at teh presence of on-screen text.

The other feature which could be introducing hocus-pocus on the signal is Picture Control. For capturing what's honestly on the tape, this should be set to EDIT. It's the second menu item on the first page of the FUNCTION SET menu. Here's a brief explanation of the feature:

Attachment 18599

My older JVC HR-S5200U has made that thumping noise after a rough patch of tape, but not enough for me to diagnose it. It isn't obvious, at least intuitively to me, what that is.

Solved! After reading this thread, particularly Lordsmurf's advice to move the VCR away from my other devices in my setup, I started preparing to do so... and noticed that when I waved my hand over my router, the thumping seemed to get a bit quieter. So I powered the router off, and the thumping immediately stopped! :laugh:

Thank goodness that was an easy fix. Now to decide whether to go through the trouble of relocating my router... or simply switching it off when capturing those particular tapes that present themselves as thumpers.

Knowing now that it was an electronic interference issue, and not the tape or VCR itself... it's fascinating that it isn't all tapes that produce the sound, or even all areas of offending tapes... just certain tapes and in certain places. :hmm:

Oh yeah - I couldn't remember what it was but reading this jogged my memory. I had the VCR sitting on top of my ES15 DVD recorder and my phone sitting nest to both. Bad idea. :laugh:

I use these on my cables even though my setup is isolated from interference:

https://www.amazon.com/dp/B08BPHCXR3

I tested them out at first by putting a router near my equipment and draping cables over it. Nasty interference as expected. Using those clip-on suppressors made a massive improvement. At that point I figured they're worth keeping on, just as extra insurance against me accidentally getting too close with an interfering device while capturing. Using something like that plus moving your setup to an isolated spot and using a good quality UPS are all helpful.

For your original question, I have some capture gear that creates BFF video, just to say that it is possible even though it's not common. Most people will be getting TFF captures.