vhs capture

[jagabo]

One of the heads on your current VCR is having problems. That's the cause of the rainbow stripes near the bottom of the frame. It's predominantly only on the top field. It's possible it's on the tape, not just a playback issue. So start by trying a different VCR. Top field on top, bottom field on bottom:



Oh, also turn off the noise filter in your capture device. It's causing terrible ghosting:

[sanlyn]

testt88 almost looks as bad as a really poor encode. There's no way to to repair it. Does the tape play that way on TV? If so, the problem is in the tape or the original broadcast.

[lj01]

No kidding? this is worse than i thought. I guess it could be any number of things. I don't necessarily think it's the VCR (which I bought just two months ago) because other tapes (even 25-year old ones) seem to capture OK (better than this one). The tape itself is about 10 years old, but the taping method was SLP/EP (there are 8 hours on one tape) so that's obviously not optimal. As far as playing on the TV, it doesn't appear as bad (and the rainbow pattern is muted or the TV doesn't detect it or something) - the quality is still not perfect but it's better than this. Is it possible this is some type of macrovision colorbursting/colorstriping that was built into either the broadcast or the cable signal?

Other than turning off noise reduction to reduce ghosting is there anything I can do? As i may have noted earlier, I'm only trying to get about 4 minutes of footage so it doesn't have to necessarily be perfect (which obviously it's far from) but is there anything i can do to mask or lessen the rainbow effect?

thanks again for taking your time to help me out, i appreciate it.

[sanlyn]

I'm not familiar with the Roxio capture device, but temporal noise filters will have that ghost and trailing effect, so jagabo is quite correct. If you're trying to reduce tape grain, the noise filters in most capture devices are not good choices. Post-capture cleaning would be more effective. And I, too, was just about to suggest: your "new" Toshiba isn't a Toshiba, it just has their name on it. I understand it was made by Funai. Today's VCR's are no match for those from a few years ago, and certainly not like the VCR's of the middle to late 1990's. There are many of them around -- I just bought one in excellent condition on eBay, among others I've found there.

You can try a capture without the denoising. IF you did want something like that during capture, you would spend a king's ransom to get a capture device with a better proc amp -- many times the cost of even a "better" card.

[Evil_Burrito]

lj01, you should send Sanlyn major thanks + a gift card for being so nice, detailed, and responsive.

Very good tip, "only one encode." Meaning, keep the video lossless until you have addressed all the problems. Once you have a good properly captured video, a hand written avisynth script is the only way to apply the necessary filters. Although you probably knew that.

The filters... Your source needs a lot of them. Deinterlacing, de-rainbowing, denoising, cropping, resizing, and (depending on the destination aspect ratio) black bars. If you are new to avisynth, it could take days to learn everything you need to know to fix your source and this could become a very long thread.

Just so you know, fixing rainbows is frustrating and difficult. It is possible to make them less annoying/visible; it is impossible to "fix" them. Unless the tape you have is extremely special, I would recommend buying a new copy on dvd or finding a digital version to download.

p.s. I will check back on this thread tonight or tomorrow.

[jagabo]

I don't necessarily think it's the VCR (which I bought just two months ago) because other tapes (even 25-year old ones) seem to capture OK (better than this one).

I would still try another deck. Sometimes particular tapes don't get along with particular VCRs.

Other than turning off noise reduction to reduce ghosting is there anything I can do?

Yes, there's lots of stuff you can do. You could use the chroma channels from the bottom field on the top field. That would give you much cleaner color. Then you can run the usual temporal filters on the video to clean it up. Attached is a quick encoding just cleaning up the chroma noise a bit.

But you really want to get rid of that ghosting first. I doubt that's on the tape.

[lj01]

ok, i'll see what i can do to scrounge up a better VCR. I don't think the Roxio device is anything great either but I'll keep at it. Thanks again for your help.

[lj01]

yes, i agree - i do owe sanlyn a major thanks + gift card. It's very kind of him/her to help out a VERY clueless person like me. I've always gotten great advice from this site, and this is no exception - unfortunately, this one is a little more complicated than i'd like it to be.

as i said, i'll work on getting a different VCR but in the meantime is there anyway anyone would mind explaining how i can use the chroma channels from the bottom field on the top field? Of course then I'll come back and ask how to run the usual temporal filters but first things first.

and i'm again - really sorry for taking up your time and much appreciate the advice, but i don't want to cause anybody any headaches - sorry about all this, it's really not that big of a deal, i guess i just never imagined it would be this complicated.

[jagabo]

is there anyway anyone would mind explaining how i can use the chroma channels from the bottom field on the top field?

This is a quick hack. The technique isn't perfect because sometimes the frame will contain fields from two separate film frames.

AviSource("test88.avi") 
AssumeTFF()
SeparateFields()
odd=SelectOdd() # bottom fields
evn=SelectEven() # top fields
evn=MergeChroma(evn, odd) # apply chroma from odd fields to even fields
Interleave(evn,odd) # back into a single stream
Weave() # weave them into interlaced frames again
ConvertToYV12(interlaced=true)
TFM()
TDecimate()
MergeChroma(last, McTemporalDenoise(settings="very high"))

I added a sample video to my previous post.

[lj01]

awesome - thanks! back to my clueless rambling, but do i run this from the command line prompt? I assume this is an avisynth script - do i just go from command line into the avisynth directory and run the code or does it happen somewhere else?

again, sorry for my cluelessness.

[lj01]

actually, i think i get it, i would do this in notepad and save as a .bat file, is that correct? otherwise, i think i can figure it out.

[manono]

No, do it in Notepad and save as an AVS, as in something like 'Video.avs'. Then open it in VDub or your encoder or favorite player as you would any video.

Most of the filters used are built into AviSynth. Except for TFM and TDecimate which are part of the TIVTC filter which has to be loaded into the script and can be found here:

http://avisynth.org/warpenterprises/

Oh, and MCTemporalDenoise:

http://avisynth.org/mediawiki/MCTemporalDenoise

Good luck getting that one going.

[lj01]

gotcha - so i save the script as avs and then open the avs file in vdub? makes sense. i'll give that a try. thanks again everyone!!

[sanlyn]

Well, some study ahead of you. Take it a step at a time. Look at it this way: if a klutz champ like me can learn this, you can. A struggle at first, but what isn't? My first DVD was a 15-minute capture off antenna into my PC. Was proud of myself. Inserted the disk into the player. The player thought about it for a few seconds, then spit it right back out.

No gift card, please, but thanks. Regulars like jagabo and manono are more advanced than I, but I keep tabs on 'em and learn from them. Being crazy enough to defy the laws of physics helps, too.

[jagabo]

gotcha - so i save the script as avs and then open the avs file in vdub?

Open the script in VirtualDub with File -> Open Video File, not File -> Run Script. The latter is for VirtualDub scripts, not AviSynth scripts.

[lj01]

ok, i'm back at it and i have in fact figured out a few things for myself, but have gotten to that point where i can't figure it out.

I believe I put the plug-ins in the right place and installed and all that correctly.

I copied the jagabo script above somewhat verbatim and it tries to open in vdub but then gets stuck on line 12, and is telling me Script Error: there is no function named "MSuper" which is in line 712 of the MCTemporal script. I read something that indicated MSuper was part of mvtools plugin so I moved that one into the plugins folder but still get the message.

Any thoughts?

Again, much thanks for helping me through this.

[manono]

I read something that indicated MSuper was part of mvtools plugin...

Do you mean MVTools2? Because that's the one you need. It's listed as one of the required filters in the MCTemporalDenoise link I gave you earlier.

[lj01]

yes - that's a bummer, that was it. it (i believe) worked when i fixed that. i came so close to almost being able to do it on my own.

ok - so once that loaded, it then came up with the split screen sort of thing in vdub. Do I save as an avi at that point? I did just to check it out and it looks cleaner of course, but the file size went from 29MB to 111MB. I'm guessing there's something else i should be doing but not sure what that is.

anyway, on the other front, i believe i'll be able to try this in another vcr tomorrow so maybe that'll fix a few things as well.

as always, thanks again for all the help.

[manono]

Do I save as an avi at that point?

I don't know. What's your final output format? If it's an XviD AVI, then choose it as a codec and configure it. To choose your codec you go Video->Compression. If for DVD or some other format, maybe choose to save as a lossless AVI (Lagarith or UT Codec or Huffyuv maybe) and save that for further filtering or for using in another AviSynth script with AviSource to encode for your final destination.

...but the file size went from 29MB to 111MB

The final size is entirely dependent on the bitrate. You have to select a codec and configure it. A lossless codec won't have a bitrate choice but isn't intended to be the final product either. If you choose nothing you get uncompressed with huge filesizes.

[jagabo]

By the way, you should probably use less heavy filtering in McTemporalDenoise. Try changing settings="very high" to "high", "medium", "low", or "very low". The result will be less plastic looking. You may have to go higher again if you get captures without the ghosting from too much "dumb" temporal filtering.

I use VirtualDub to view the results of my scripts. You can also use a media player or other editor that supports AviSynth scripts. You can save the results using any editor/converter that supports AviSynth input.

[sanlyn]

I copied the jagabo script above somewhat verbatim and it tries to open in vdub but then gets stuck on line 12, and is telling me Script Error: there is no function named "MSuper" which is in line 712 of the MCTemporal script.

Sorry I was out for a while and missed all the action. To add to manono's advice earlier, I looked up an earlier ZIP compilation of files required by MCTemporalDenoise (MCTD for short) and attached it. Likely you have it going by now. The ZIP has 3 folders inside -- Avisynth plugins, some documentation on then, and a copy of FFTW3.DLL . Many of these plugins are used by other scripts.

MCTD is a tuned, orchestrated collection of filters that can also be used as standalones. It comes as an "avsi" (autoloading) script, which is a text file. The most current documentation is the avsi itself, which you can open in Notepad. Expand Notepad's window horizontally, because the top half of that long script is commentary, lists, and tables. Fun stuff, huh? The script itself is the Bible for MCTD -- the wiki web page on the internet has errors.

[lj01]

Thanks everyone. I'll be picking up an older (mid-90s as you suggested) VCR later and giving it a try with a longer piece of material. I'm hoping I won't have any further questions but I would say it's possible and/or likely I will, but I hope things are at a stage where I can work these things out on my own.

Once again, just want to point out that I really appreciate everyone who has taken the time to advise me, I know sometimes it's hard to be patient with a beginner who wants a quick easy fix, but everyone has been great and it's awesome that you take time to help people out. This stuff is amazingly more complex than I ever imagined, and I still don't know what 90% of it means but this has been some great help, and I much appreciate everyone who has chimed in.

[lordsmurf]

It's just chroma noise.
The VCR or tape is to blame.
Don't deinterlace.

[lj01]

ok, i'm back. couple questions:

in running the script, i notice that my original 29.97 fps is output to 23.976 fps. Should I encode at 23.976? And/or would it matter if I'm going to end up authoring at 29.97 anyway? and/or is there a way that the script could churn out a 29.97 or would that not produce the desired effect?

everything's working great, by the way, thanks to everyone.

[manono]

in running the script, i notice that my original 29.97 fps is output to 23.976 fps. Should I encode at 23.976?

Yes.

And/or would it matter if I'm going to end up authoring at 29.97 anyway?

Yes, it matters. You want to encode at progressive 23.976fps and apply pulldown either with your encoder, or later with DGPulldown. This assumes you're making an NTSC DVD.

...and/or is there a way that the script could churn out a 29.97 or would that not produce the desired effect?

You don't want the script to be for 29.97fps. That's what the IVTC did (the use of TFM.TDecimate), restore your hard telecined interlaced 29.97fps video to its original progressive 23.976fps.

[lj01]

i see - so I can encode as separate mpg streams and use dgpulldown to convert from 23.976 to 29.97 - that will work? thanks.

[manono]

i see - so I can encode as separate mpg streams and use dgpulldown to convert from 23.976 to 29.97 - that will work? thanks.

Yes, it will work. That's what 3:2 pulldown is - flags added to the video stream so progressive 23.976fps is output as interlaced 29.97fps (or, more accurately, 59.94 fields per second..