Improving old VHS ¿What to expect?

[Marto2008]

Hi to all. I'm capturing some old VHS (20 to 30 years old) and I would like to know what kind of improvement can I expect.

My capturing system:
Core i5 4gb 7.2K RPM HDD
ATi 650 USB
VirutalDUB 1.9.9
Lagarith Lossless codec.
Samsung SV-K182P standard VHS (6 head)
And probably this converter/TBC http://www.dcacpower.com/product/video.html

I've been trying some VirtualDUB filters and some AVISynth scripts ("the power of avisynth which is not for vhs, right?) but there is something that does not convince me, maybe I'm expecting too much with too little hardware or maybe I'm not doing things right.

UPDATE: I also tried the script that johnmeyer recommends here:
https://forum.videohelp.com/threads/308840-old-VHS-restoration/page2
But I could not make it work, getting error: "There is no functional named SetMTMode"

Video 001 = captured no filters
Video 002 = captured and deinterlaced with ffdshow cubic interpolation

One problem I notice is the "warping" on vertical things... like ilumination post or trees, also some "greenish" ghosts (what is that?)

Hope you can enlightme.

[Gavino]

I also tried the script that johnmeyer recommends here:
https://forum.videohelp.com/threads/308840-old-VHS-restoration/page2
But I could not make it work, getting error: "There is no functional named SetMTMode"

You need the special multi-threading version of Avisynth to use SetMTMode.
The easiest solution is just to remove those lines from your script - it should still work, though possibly slower.

[Marto2008]

Yes, thank you for your asnwer I already made that script work with MT and without (just like you say taking out those lines).

[2Bdecided]

Your captures don't look that bad (though the deinterlacing in 002 is poor).

The levels probably aren't right.

Lagarith Lossless codec.
Samsung SV-K182P standard VHS (6 head)

You're losslessly capturing a poor signal. If you want it to come out better, start with something better - i.e. a better VCR.

And probably this converter/TBC http://www.dcacpower.com/product/video.html

Is this a TBC? Is this really going to improve the quality of the signal? I have my doubts.

I've been trying some VirtualDUB filters and some AVISynth scripts ("the power of avisynth which is not for vhs, right?) but there is something that does not convince me, maybe I'm expecting too much with too little hardware or maybe I'm not doing things right.

I don't think the 8mm film script is the right place to start at all. Figure out what you want to fix, then find things to fix it - don't start with something so complicated.

One problem I notice is the "warping" on vertical things... like ilumination post or trees

A suitable TBC (in a high end VCR, or in certain DVD recorders in loop-through mode, or in certain DV camcorders' analogue inputs) should fix this.

also some "greenish" ghosts (what is that?)

No idea what you mean - if no one else knows, maybe post a screen cap showing this?

Hope this helps.

Cheers,
David.

[jagabo]

As has been pointed out, you need a TBC to fix the horizontal squiggles. A used Panasonic ES10 or ES15 DVD recorder in passthough mode will work pretty well. There is a software TBC for AviSynth but it doesn't work very well It will likely make your problems worse, not better.

Look into VirtualDub's Chroma Noise Reduction filter by Gilles Mouchard. That will reduce the flickering in the chroma channels.

You may need to shift the chroma channels left by a few pixels. Flaxen's VHS filter in VirtualDub can do that. Or ChromaShift() in AviSynth.

You have some very hard clipping of darks and brights (at the top and bottom of the wave form monitor):



Look into your capture process and see if you can eliminate that. Doing so will get you more detail in the bright and dark areas.

[Marto2008]

First of all thank you for your answers.

2Bdecided: I'll look for a TBC (Datavideo TBC-1000 is suitable for my needs?) If I do not get better results I'll get a better VCR.

Jagabo: How can I eliminate the clipping? Already trying Chroma Noise Reduction thx.

Any suggestion on the deinterlacing??

Best Regards.

[jagabo]

How can I eliminate the clipping?

Set your capture device to output YUY2 video. If you capture device has any options for clamping illegal luma and chroma values disable them. Don't let VirtualDub (or any other software) convert to RGB while capturing (don't use any filters while capturing). Set Lagarith to work in YUY2 mode.

Any suggestion on the deinterlacing??

Don't deinterlace unless you really have to. DVDs and TVs support interlaced video. If you really need to deinterlace (for uploading to Youtube for example) the best for most material is AviSynth's TempGaussMC_beta1mod() but it is very slow (a few fps on a fast computer). Yadif() (both in AviSynth and VirtualDub) is pretty good and not so slow.

[Marto2008]

Thanks again for your answers.

I do capture in YUY2, it is the only option available when I use the ATi 650 in Windows 7. I also use YUY2 in Lagarith codec. Am I not seeing something??

Will try TempGauss, it seems that I need more script knowledge as I do not know where to start.

I may buy this SVHS = JVC HR-S6800U, do you think it is up to the task?

Best Regards.

[jagabo]

The line TBC in the JVC S-VHS deck should help with the horizontal jitter.

Just getting to the point where you can use TempGaussMC_beta1mod() is bit or work. Assuming you already have AviSynth installed, start here:

http://avisynth.org/mediawiki/TempGaussMC

That page has links to the filters it requires, MvTools, etc. Download each of the filters and extract the DLL, AVS, and AVSI files to AviSynth's plugins folder. You might also extract any TXT or HTML help files to there too.

Your script will look something like:

AVISource("001.avi") #open the source video
AssumeTFF() #your video is top field first
ConvertToYV12(interlaced=true) #TG requires YV12 (it comes out of AviSource as YUY2)
TempGaussMC_beta1mod() #produces a 60 fps video, each field of the source becomes a frame
SelectEven() #cut it down to 30 fps (if you want)

TG did a little better but the thin line on the side of the car is still a little jagged:

[Marto2008]

Thanks Jagabo

I managed to get TempGaussMP script working, lot to learn still but the results are great.

My capure device has a 3d Com Filter and a Noise Reduction Filter, these are "options for clamping illegal luma and chroma values"?? I'll try disabling them and see If I get any better results.

Best Regards

[jagabo]

My capure device has a 3d Com Filter and a Noise Reduction Filter, these are "options for clamping illegal luma and chroma values"?

Not specifically. But many programs convert YUV video to RGB for filtering. That process can result in clamping. So definitely run a few tests with the filters off. You can use AviSynth's Histogram or VideoScope filters to see luma levels of YUY2 video.

[Marto2008]

I've been trying all sorts of configurations.

My capture PIN and my Lagarith options both say YUY2.

Now I'm using Avisynth Videoscope but it is really over my knowledge as I do not know how to identify LUMA clamping.

My script:
AviSource("original.avi")
#ConvertToYUY2()
Tweak(sat=0.8)
VideoScope("both", true, "U", "V", "UV") # frame 3871

Sorry for my lack of knowledge, maybe you can suggest me a guide on luma and chorma for dummies.

Best Regards.

[jagabo]

In the Videoscope image I posted earlier, look at the top of the graph. Notice how it is all empty (all black, except for the tick marks)? And just below the empty area are some very bright horizontal line segments. Those bright spots are caused by luma peaks that should have been in that empty area but where squished down to fit below Y=235 (IRE 100). Video isn't supposed to have luma values above 235 but in practice often does. Camcorders and VHS tapes in particular.

At the bottom of the graph there is another empty area with some bright segments just above it. That is the same thing happening at the bottom of the luma scale. Video shouldn't have luma values below Y=16 (IRE 0) but your did have a little.

The cutting off of the peaks and valleys like this is called coring or clipping. I see in the config dialogs you have a noise reduction setting with "Luma coring". That may be where the coring was happening.

Optimally, what you want is for the darkest parts of the video to be at Y=16 without any clipping, and for the brightest parts to be at Y=235 without any clipping. Are there any processing amp settings where you can adjust the brightness and contrast of the picture before capturing? Of course, not every frame will have the full excursion from Y=0 to Y=235. Adjust the the proc amp so that the brightest spots in the brightest shots are at 235, and the darkest spots in the darkest shots are at 16.

[2Bdecided]

Any suggestion on the deinterlacing??

Don't deinterlace unless you really have to. DVDs and TVs support interlaced video. If you really need to deinterlace (for uploading to Youtube for example) the best for most material is AviSynth's TempGaussMC_beta1mod() but it is very slow (a few fps on a fast computer). Yadif() (both in AviSynth and VirtualDub) is pretty good and not so slow.

I know the common advice for faster-than-tgmc-but-still-quite-good is to use Yadif or YadifMOD, but have you seen this...

http://forum.doom9.org/showthread.php?p=1374359#post1374359

...that's TGMC with settings to disable most of the slow stuff, making it faster and better than YadifMOD.
(see the next post in that thread for a visual comparison)

tempgaussmc_beta1u(1,1,0,0,0,0,edimode="--",SVthin=0.0,pelsearch=1)

Hope this helps.

Cheers,
David.

[jagabo]

I saw mention of that a few days ago but haven't had a chance to try it out.

[Marto2008]

Jagabo, thankyou for your Videoscope explanation, I'll try to learn from that. Sadly my ATi650 does not have any "processing amp" when I run it on Windows 7, in Windows XP I do have, contrast-brightness-sharpness-etc... will try XP for capture.

2Bdecided, with that settings and downloading TempGaussMC_beta1u I'm getting around 12fps (5fps with the normal script) It's quite good but I think I'm not setting it for multithread...

Best Regards

[jagabo]

I tried a quick test with TempGaussMC_beta1u(1,1,0,0,0,0,edimode="--",SVthin=0.0,pelsearch=1). It was about 5 times faster (no other filtering) than TempGaussMC_beta1(defaults) but it left more artifacts. Yadif() was an order of magnitude faster than beta1u and left even more artifacts. This was on some anime where the artifacts are most noticeable.

[creamyhorror]

If the fast TGMC settings are both faster and better than Yadifmod+NNEDI2 (as Didee's tests seemed to show), then I'd personally consider those a prime choice for deinterlacing.

[Marto2008]

Jagabo,

I've installed Windows XP so now I have some Procamp to adjust Contrast and Brightness before capturing...

I also tried Avisynth's Histogram so seek the right Contrast / Brightness and I would like to ask you If I'm right with my findings.

This is my conclusion (after your advices and some Doom9 guides):
I have to adjust Contrast so I don't get "yellow" dots on the left vertical brown line but also to get the closest to it.
I have to adjust Brightness so I don't get "yellow" dots on the right vertical brown line but also to get the closest to it.

Maybe it is just my imagination, but I think i get a better image doing this...

Best Regards.

[jagabo]

When capturing VHS you have to consider all the noise and overshoot from the players sharpening filters. It's OK to have a little picture in the yellow bars. You want to avoid having too much. You also need to consider that not every shot has to reach the extremes. Some won't have the darkest shades, some won't have the brightest. So you have to scan through your video looking for a variety of shots.

That particular shot looks very washed out to me. There are no blacks.

[Marto2008]

Thanks again for your advices, I'll lower a little contrast and give a little more brightness.

Best Regards.