VHS Capturing noob - what do I need to own and know?

[jagabo]

Do you have a video source playing (your VCR)?

[koberulz]

Yes.

[jagabo]

All I can suggest is you go through each input and output pin and examine the properties. Make sure you're set to capture with the right frame size, frame rate, sample type, etc. Are there any other Hauppauge filters available? Maybe you need to add another one to the graph.

[koberulz]

...I still had VirtualDub open in capture mode. Closing that got the video preview working in GraphStudio.

MPC is now giving a 'DirectShowSource: unable to determine the duration of the video' error.

[jagabo]

Media players may need a video length. You can add that to your DirectShowSource() arguments:

DirectShowSource("graph.GRF", FrameCount=10000)

[koberulz]

Success! Although there's a weird green area at the bottom, and all I can get in VDub is whatever frame it happens to be on when I open the AVS, so this took a while to pull up.

ETA: It doesn't matter what I do with the proc amp settings, there are no superblacks. There are, however, superwhites very briefly during the transition from the wrestling to Hot Property, and if I pump brightness and contrast way up, they appear throughout the rest of the tape as well.

[jagabo]

It looks to me like you have a 720x480 picture in a 720x576 frame, ie an NTSC vs. PAL issue. Maybe you have the frame size set wrong somewhere.

By the way, you do have super blacks but I'm pretty sure it's the green bar at the bottom of the frame. You could use Crop(0,0,720,480) before Histogram() to eliminate that.

[koberulz]

Ah, yeah, there was a GraphStudio picture setting which I'd set to 'Unknown' when I was having issues with the AVS, setting it back to PAL_I got rid of the green area and the superblacks (which slipped past me thanks to never moving at all, no matter how much I played with the proc amp or what was on the screen). Now it's as I said, no superblacks, occasional superwhites, fiddling with the proc amp can get me more superwhites but can't introduce superblacks.

So am I supposed to make sure the whites are as high as they can get at this stage, or should I just make sure everything is inside the black and worry about the rest of it in post? I upped the brightness until the whites were as white as I could get them, I've attached a sample capture.

[koberulz]

I figured out the laptop issue: I had the wrong audio device selected. I've got VDub, GraphStudio and Lagarith on there at the moment. I'll obviously need AviSynth...is there anything else I'll need on the laptop to get it doing what the desktop is doing?

[jagabo]

So am I supposed to make sure the whites are as high as they can get at this stage, or should I just make sure everything is inside the black and worry about the rest of it in post?

In general, you want to keep the histogram in the black area. With the darkest darks just above the bottom brown area and the brightest brights just below the top brown area. But VHS is prone to a lot of faults so you have to use your judgement a bit. For example in your testcap3.avi:



Notice how there are oversharpening halos at the transitions from dark to bright or bright to dark. Some of the bright halos extend into the super brights. And at the other end there would have been some overshoots into super darks but your capture device has clipped them. After reducing those halos with dehalo_alpha(rx=6, ry=1, brightstr=0.9) you get:



Those sharp overshoots are very much reduced. My guess is the bright white areas were originally very close to Y=235, right below the top brown bar. And the darkest blacks were just above the bottom brown bar. The remaining humps at the left side of the peaks are probably another defect of the VHS deck, or possibly from multigeneration copying. So the original broadcast probably had levels more like:



In a case like this you don't mind the peaks protruding into the brown bars because you are going to fix them later. Even if you don't plan on fixing them they are a defect that you don't care about, not a real detail of the image.

[koberulz]

Any particular reason it would be clipping the blacks but not the whites?

The other thing in the doom9 guide I'm not sure about is the "active capture window" thing. All the numbers and references and such kind of lost me; I'm not sure what size/area/whatever I should be capturing?

[jagabo]

I don't know why but a lot of capture devices clip at Y=16 or thereabouts.

All you really need to know about the active capture window is that you want to capture 720x576 or 704x576. With an analog PAL source the active picture of a rec.601 cap is about 702x576 pixels. That represents the 4:3 or 16:9 image. The extra width of the cap is just to make sure you get all of the picture in case it's broadcast or captured off center. The extra pixels are usually black -- hence the black borders at the left and right edges of all your caps.

Pretty much every PAL DVD made from analog tapes doesn't worry about the difference between the DVD spec (the full 720x576 frame is scaled to the final aspect ratio) and the rec.601 spec (the inner 702x576 pixels of the 720x576 frame are scaled to the final aspect ratio). They just capture with standard rec.601 devices and burn the resulting 720x576 frame to DVD. If you're a real stickler for aspect ratios you can crop your 720x576 frame down to 704x576 (still a valid frame size for DVD).

[koberulz]

But that guide seems to indicate different devices capture different widths? So if I capture 720x576, it's capturing some random number of horizontal pixels and stretching/squashing to 720?

[Brad]

That was a problem with some early capture devices. The guide is old. Even cheapo devices tend to get it right these days.

[koberulz]

Assuming I'll need S-Video cables, is there anything I need to know before buying?

[jagabo]

Assuming I'll need S-Video cables, is there anything I need to know before buying?

Don't go super cheap. On the other hand don't waste your money. About US$10 will get you decent 6 foot s-video cables.

[koberulz]

The VCR arrived today. Plays the tapes fine - and the line TBC has done wonders - but when not playing a tape, it's pretty useless.

Navigating the menus is hard enough already (they're in German), but with this it's basically impossible.

EDIT: I also can't open the AVS file in MPC on my laptop...is there a codec or plugin or something I've missed?

[koberulz]

Apparently I can't edit an attachment into a post.

[Skiller]

It's probably because the VCR outputs it's menus in "LDTV" mode; meaning it's PAL but basically without interlace (288p). This is to prevent the menus from bobbing up and down by one scanline 50 times a second. Using LDTV they appear rock solid and steady on a CRT but capture devices often struggle with this slightly non standard PAL.

You should be able to view the menus properly on a TV though.

[koberulz]

There's no composite video out, and my TV doesn't have S-Video in, so I figured that was my only shot. But digging around in a box of old cables I found a SCART to RCA cable, and yeah, it looks fine on TV (apart from still being German, but that's to be expected).

Any ideas why I can't open the avs file in MPC?

[koberulz]

In the meantime, here's what the histogram looks like with the capture device on default values coming through the new VCR:

[jagabo]

In the meantime, here's what the histogram looks like with the capture device on default values coming through the new VCR:

No dot crawl artifacts. But crushed blacks. See if the proc amp can bring those up.

[koberulz]

Is crushing the same as clipping, or is that a different thing?

What's the peak on the left?

[jagabo]

Is crushing the same as clipping, or is that a different thing?

Same thing.

What's the peak on the left?

That's an oversharpening artifact -- probably from the VHS deck that recorded the tape (since it also happens with playback on your other VCR). Notice how there is also a very bright vertical bar in the image below the peak. If you look closely you'll see excursions into super brights everywhere there's a horizontal transition from back to white.

[koberulz]

If it's the same thing, haven't we already established that the capture device is clipping it and there's nothing the proc amp settings can do?

[jagabo]

If it's the same thing, haven't we already established that the capture device is clipping it and there's nothing the proc amp settings can do?

That was with a different VCR. Trying different settings with this deck may give different results, depending on where the crush is happening.

[koberulz]

The AVT-8710 arrived today. Still only have the one S-Video cable, so I ran S-Video between the Philips and the AVT, then composite from the AVT to the USB-Live2. Capture mode in VirtualDub works fine, but the AVS file gets a timeout error waiting for the graph to run. I get a black screen when trying to render the Capture pin in GraphStudio.

I also got ghosting on the VCR menu at one point, which means the AVT is probably faulty. Fantastic.

[PuzZLeR]

I also got ghosting on the VCR menu at one point, which means the AVT is probably faulty. Fantastic.

The AVT-8710 can have multiple problems with VCR menus. It misinterprets the signal, and goes out of sync, and can even emit a checkerboarding artifact pattern layered over the captured video much like crosstalk.

Best to just power cycle it and try again, but this time completely avoid the start of any filtering with it until you are away from these menus.

I'm still undecided as to whether such AVT-8710 quirks are from it being "faulty" or "flawed" (which are not synonymous), or maybe a combination of the two.

[koberulz]

There's a discussion about it on DigitalFAQ and they've confirmed that problem units have a different chip to the properly functioning ones.

Further testing has confirmed mine is faulty, so I've had to get it replaced.

[PuzZLeR]

There's a discussion about it on DigitalFAQ and they've confirmed that problem units have a different chip to the properly functioning ones.

Further testing has confirmed mine is faulty, so I've had to get it replaced.

I'd say it's more flawed, not faulty then.

It's not that the odd unit is problematic anymore with this model, it's the whole MFG line itself. I doubt your next one will be any better. Not to be negative, but I read those threads too, and even experienced said problems, and have since investigated and adopted other options.