Filters for VHS

[zilog jones]

I'm planning on doing a few PAL VHS to DVD conversions, and was wondering what filters you recommend?

Most of it's home-recorded stuff, usually recorded off far from perfect cable/antenna receptions (I often get those scrolling diagonal lines on cable). I don't have the best of VCRs either for the transfers - it's one of those new really cheap 'n nasty JVCs made in Indonesia, but it's the only 4-head (hi-fi+LP) deck I have. I suppose the heads will be clean at least.

I assume GuavaComb and CNR2 would be good to start off (I'll have to put up with composite video), but what else? Most of the stuff I want to transfer is film.

What would be the best way to set my VCR? There's some basic sharpness settings on it (JVC give some TLA like "EPC" or something like that, so it may be more than just sharpness?) - soft, normal, and sharp. If I have it on sharp, would it be possible to gain more quality out of a pretty good recording after some filtering?

There is a special case I want to see if I can do anything about - it's some junk recorded in 1989 (the oldest tape we have) - there's not much I want from it except for a few hilariously crappy ads. Only problem was they were recorded with a pretty snowy reception (no ghosting or anything, though). And the tape's 15 years old! If I set the VCR to "soft" the snow is is nearly gone, but it's quite blurry. However if I put on sharp, it's horrendous. Should I just leave it normal and use a lot of filters, or just cap it with the "soft" setting and use less filters?

And one more thing - nearly all of this stuff is recorded with non-Hi-Fi VCRs, so you can guess the sound ain't great. Anyone know of any decent programs (i.e. FREE programs) for making it in any way better, or at least do some noise reduction?

[Mug Funky]

if it's for hilariously crappy ads, then i would leave the sound as is, save for a bit of EQing according to taste. you could do that in practically any program..

i'd probably cap on "normal" rather than soft or sharp. sharp will just amp up the high frequencies and make everything compress worse, and i can't be sure that soft is an actual filter, or whether it's the lack of a filter.

in either case, you can mimic the effect of these filters using some masking and the lowpass feature of Fizick's DeFreq. defreq will also kill the diagonal moving lines (that's what it was written for).

denoisers might handle the snow pretty well, but it really depends how bad it is. maybe removedirt or degrainmedian could work wonders here, perhaps followed by peachsmoother or something.

pixiedust apparently is the mother of all denoisers, but i never got loadpluginEx working properly (i could do it i guess, but at the time it wouldn't work and since then i've got lazy :)) so i haven't tried it. apparently it's slow as molasses, but works very well.

remember though, if you're just capping this stuff to have a laugh at how tragic the '80s were, there's no shame in leaving it how it is. the VHS look is very '80s in itself, and if you can spare the bitrate, could actually complement the content (sort of like how hip and trip hop acts will deliberately put vinyl surface-noise in their CDs).

[edit]

btw, can i ask what the ads are? i can barely remember anything from the late '80s. the "expo '88" ads were tragic, i remember that much.

[zilog jones]

Actually, after looking back at the video they weren't really that interesting/funny ad's. There's this diabolically corny Coke ad with a load of kids singing about friendship or unity or some crap, the christmas PG Tips ad (it's tea, advertised by MONKEYS!) that used to be on EVERY year, an ad for Carling Black Label (with a squirrel - it's been on those shows about ads before), a really lame american Wrigley's Spearmint ad, a corny american ad for Radion (washing powder - yeah, remember powder?) hideously badly-dubbed with English voices, an ad for a Hitachi VCR (the last time I ever recall Hitachi advertising on TV over here) showing off its electronic timer function (gasp!), an ad for Scotch video tapes with that skeleton guy (coincidence that it was recorded on a Scotch tape!) and some other junk.

There's also some continuity stuff and ID's for TSW - one of the localised ITV channels in the UK (the South-West one) which hasn't existed in over 12 years, which some may find interesting. Though they also may find test cards interesting...

[zilog jones]

I got Pixiedust to work OK, with great results, though personally I think the default level 5 is smoothing a bit *too* much. But, as you said, it's slow as "molasses" (I assume that's a very slow thing). Instead I was thinking of PeachSmoother and VagueDenoiser - good idea?

Can anyone else recommend what they typically use with VHS cap's?

[Boulder]

I'd give CNR2 a go, just make sure you've got the latest version, v2.61. I use CNR2(ln=25,un=25,vn=25) on all my analog caps.

PeachSmoother is a very good one as it adapts to the noise quite nicely. RemoveGrain and RemoveDirt might also be worth trying.

[kingmob]

I'm very happy with RemoveGrain RemoveDirt on my captures. It gave me similar quality as pixiedust, but at a much higher speed.

[zilog jones]

So you think I should use those two instead VagueDenoiser, then?

I was trying CNR2 last night, but it didn't seem to be doing anything at all for some reason. Same goes for GuavaComb, which I was testing while capturing with the VCR's OSD on (it was rainbow-tastic!). The video was in YUY2 - what could have caused them to not work?

I'm pretty sure I was using CNR2 2.61, I'm using AviSynth 2.55, and it was just normal progressive PAL... oh, wait it was 696x576 - could that be the problem? I forgot about the whole mod 16 thing...

[Mug Funky]

i haven't yet found something i like for VHS caps. i'm cooking up something with MVtools and removedirt/degrainmedian/whatever else. i'm not happy with it yet, and it crashes without warning...

oh, btw:

http://dictionary.reference.com/search?q=molasses

:)

treacle, basically. hmm... bit of an americanism i guess, because i only ever say "molasses" in that phrase. heh.

[zilog jones]

Yeah, it's one of those phrase words I hear a lot but never bother finding out what it really means :D

Thanks for the help, people. I'll try out these filters (after first making my videos a non-silly resolution ^_^), and will probably be back on Monday complaining how something still doesn't work ;)

[Boulder]

Originally posted by zilog jones

I was trying CNR2 last night, but it didn't seem to be doing anything at all for some reason. Same goes for GuavaComb, which I was testing while capturing with the VCR's OSD on (it was rainbow-tastic!). The video was in YUY2 - what could have caused them to not work?

If you want to see the effects, it's a good idea to use Subtract().

AVISource("path\crappy_clip.avi")
a=last
b=last.CNR2()
Subtract(a,b)

[zilog jones]

I was comparing it to the same script, just without CNR2, and had them opened on two separate VDubs. They looked identical. But as I said I think the screwy resolution could have caused it not to work (many things require resolutions divisible by 16), so I'll pad it to 704x576 and try again.

Thanks for the subtract thing - I never thought about using that to compare stuff.

[Boulder]

With CNR2 the changes are very subtle as you can see if you use Subtract. You can make it more aggressive but risk getting chroma ghosting, which is very annoying.

[zilog jones]

It turns out CNR2 was working all the time - it was a lot more noticable on a non-pre-recorded tape, especially at the start of recordings where it goes all funky.

But GuavaComb doesn't seem to be doing anything! I tried everything I could think of, and it's not doing anything at all. My script was (for PAL 696x576 Huffyuv):

avisource("g:\cap\cap1.avi")

Letterbox(8,8)
addborders(4,0,4,0)
telecide(order=1)

GuavaComb(mode="PAL")

GuavaComb did NOTHING! I tried putting converttoyuy2 before it - I even tried doing it the interlaced way and it didn't work either. Something hates me...

[zilog jones]

Hey, could someone give me an example script of how you would use RemoveGrain/RemoveDirt/PeachSmoother/whatever with typical VHS captures? I don't even know where to start...

I'm currently getting good results with PixieDust(limit=2) (I think the default smooths a bit *too* much), but QuEnc's predicting over SIX HOURS for a half-hour 704x576 MPEG-2 encode! I suppose that's a Pentium III fer ya, but if I ever want to do any films I'll have to think of something quicker.

[Boulder]

This is my script for a Sherlock Holmes-capture I did today:


MPEG2Source("c:\temp\captures\holmes.d2v",idct=7)
#audio=WAVSource("g:\temp\captures\holmes.wav")
#AudioDub(video,audio)
#DelayAudio(-0.044)
Trim(575,74850).FadeIn(5).FadeOut(250)
FieldDeinterlace(blend=false,full=false,threshold=100) # Subs are sometimes combed!
ChromaShift(C=-2,L=2)
RemoveGrain(mode=2)
Crop(16,2,-16,-6,align=true)
ColorYUV(off_y=5,gain_y=-16) # see the analog capture guide for this
CNR2(ln=25,un=25,vn=25)
TemporalSoften(2,4,5,15,2) # or RemoveDirt(cthreshold=30)
UnFilter(-3,-3) # slight blurring to clear some temporal cleaning artifacts
BilinearResize(656,544)
Limiter()
AddBorders(24,16,24,16) # 2 blocks overscan, values from FitCD
ConverttoYUY2() # not needed for QuEnc

[kingmob]

This is what i used last. I used it to try out iip with removedirt, so it's slow as hell (yet faster than with pixie ;)). I'd normally use limitedsharpen instead of iip.
The funkydenoise script is there for making peoples skin look nicer, it blurs a lot though. If your interested in it, i suggest you use the search.

SetMemoryMax(128)

Avisource("capture.avi").ConvertToYv12()

LoadPlugin("D:\AviSynth 2.5\plugins\undot.dll")
LoadPlugin("D:\AviSynth 2.5\plugins\masktools\MaskTools-v1.4.16.dll")
LoadPlugin("D:\AviSynth 2.5\plugins\WarpSharp.dll")

#Import("D:/avisynth 2.5/plugins/limitedsharpen.avs")
Import("D:/avisynth 2.5/plugins/iip.avs")

Telecide(order=1,post=2)
Crop(8,2,0,-2).Removegrain().RemoveDirt()
Funkydenoise(radius=10,cut=0,rolloff=15,gamma=4)
iip(dest_x = 640, dest_y = 480, duststr = 0, dustweight = 0)

The only important thing for removedirt is that you use it as soon as possible. Defaults always seem to work fine for me. It is important though to crop before removedirt, as describes in it's tutorial.

[zilog jones]

Thanks! I got pretty good results using something like Boulder's (sorry I didn't see the other one till today), except using RemoveGrain(mode=5) (I found 2 a bit too blurry) and RemoveDirt(mthreshold=70) (I assume "cthreshold" was a typo?). I got very similar results to PixieDust(limit=2) in half the time!

Only thing is I'm getting slight blockyness around moving objects in front of still scenes. I don't know if this is a side-effect of RemoveDirt or if it's digital noise that was originally in the recording (my crappy analogue cable is mostly sourced from digital satellite - and not always the best of digital receptions either)?

Also, what's the best way of getting rid of that horizontal wobbling of the picture on VHS tapes?

[Boulder]

RemoveDirt(mthreshold=70) (I assume "cthreshold" was a typo
No typo there. I've raised the threshold for chroma because blocking can't be seen as easily as in luma.

[zilog jones]

But there is no "cthreshold" :confused:

I can't see anything about it in the html file that came with it, and AVISynth said it wasn't right either...

[Boulder]

It's a known bug in RemoveDirt. Sometimes it accepts it, sometimes it doesn't. It is mentioned in the documentation, by default it is the same as pthreshold (luma) = 20.

[zilog jones]

OK, here's that tape from 1989 I was talking about:

http://www.skynet.ie/~zilog/pics/crappy_original.png
As you can see, it ain't great. But it's mostly not the tape - there's a recording from a different channel after this on the same tape and it looks pretty good.

I use the filters we were talking about before (RemoveGrain(mode=5), RemoveDirt, UnFilter(-3,-3)), and I get this:
http://www.skynet.ie/~zilog/pics/crappy_filtered.png
It's kinda better, but still quite noisy. I tried PixieDust(limit=7) instead of RemoveGrain/RemoveDirt and it was a lot worse. Basically how do I make RemoveDirt just generally stronger? There's too many confusing parameters for my simple mind!

I don't care about compressibility at this stage - I just want to try and make it look as good as possible without removing too much detail.

Also, are there any other filters which could help do a good job at removing all this noise? There seems to be slight ghosting to the right, too - what could I do about that?

[Boulder]

There's not much you can do if the noise is very strong. It will look better a bit noisier than with a very blurry image. You could try PeachSmoother without any parameters and see what happens. Also try ReduceFluctuations(limit=x) in which x is an integer. The filter is included in the RemoveDirt.dll.

[zilog jones]

OK, I'll try those out. I know trying to get a perfect picture out of this is like trying to make to make democracy perfect, but I can try :D

[leonid_makarovsky]

I'm also looking for filters for VHS.

I have a PAL VHS that was manufactured in 1994. It had been sealed in a shrink wrap and never been played until yesterday. I put it in my VCR and the image quality was amazing. However, I'd like to first remove this blue-ish noise that usually appear when image is darker. (Is it what is called "spatial noise"?) And then I'd like to sharper the image. So what would gurus here recommend for sharpening the image and the removal of those blue-ish thing?

The thing is that the DVD of that footage exists. However, the DVD is missing about 40% of the footage. That's why I'd like to have the whole thing. Comparing DVD and the VHS, I noticed that the DVD most likely was recorded from the VHS. It does look just a bit sharper, but not much. I'm pretty sure I can achieve the same sharpness applying AVISynth external filters. Thanks in advance.

--Leonid

[tsp]

Zilog jones: You could try my ml3dex filter. It's included in the medianblur filter download here (http://forum.doom9.org/showthread.php?s=&threadid=84636)

use it like this:

ml3dex(thSCD1=1500)

It should remove some more of the noise.
just remember to get MVTools also.