vhs capture

[lj01]

Using Roxio USB capture device - I get a red/blue/green wavy line sort of thing going on (see picture - this is the bottom half of a screen) - is this some kind of interlacing problem or something I can filter out?

[Brad]

Rainbow pattern at the start of a program caused by recording over other existing content without a flying erase head?

Or is it throughout your recording?

[lj01]

thanks for the reply - it's throughout. i tried again using virtualdub and applied a chroma filter - not sure if that helped but the result was about 100x better. i was using windows movie maker, capturing as a wmv.

[hech54]

i was using windows movie maker, capturing as a wmv.

Yuk.

[lj01]

yeah, that was probably my first clue.

[lj01]

sorry again to bring this up but is there some way I can rectify this? As mentioned I've been working in virtualdub which has improved things a bit but I'm still getting this rainbow noise/etc in converting. Is it most likely my capture device that's causing the problem? And/or is there any filtering in vdub i can do? it's almost like a wavy pattern of red/green/blue sometimes more intense than other times. Is there something I can run it through post-capture?

any thoughts/help is appreciated - thanks!

[lj01]

hi - does anyone have any thoughts? I just can't imagine this being that uncommon of a problem. I'll give a more complete elaboration in hopes that someone might be able to point me in the right direction.

I have a Toshiba VCR - it's new so even though it's not a great machine, it should be able to do the trick. In fact it plays fine on the TV directly. Tapes are older, but not too old, like 10 years old. The quality is not fantastic, recording was done in XP (6 and sometimes 8 hours on one tape)...

My current method is that I have Roxio cables connected to my Windows XP laptop. I am capturing through virtualdub, and I was applying the chroma filter that comes with it. That improved matters over my horribly misguided first attempt at using Windows Movie Maker as I mentioned but it's still not totally getting rid of the rainbow-ish splotchy colors. I am capturing to a lossless avi (huffyuv) and then encoding but the rainbow/splotchiness appears in the file before I encode.

So...is there anything I can do? In reading, I've come upon stuff that says it could be a simple case that i should fast forward the tape to the end and then rewind back to the beginning to sort of reset the spools - but then if that were the only problem wouldn't i be getting the splotchiness when I view on the regular TV?

Is there some kind of filter I can use, either during capture, or on the AVI file once it has been created? As you can gather, i'm not a professional and my project is pretty minimal - I'm trying to get 4 minutes of footage out of each of several episodes of a TV show taped 10 years ago. I don't want it to look like total crap, but I don't want to spend hundreds of hours trying to perfect it.

Thanks for any ideas or help, I have gotten great advice from this site over the years, that's for sure, so hopefully someone can point me in the right direction. Thanks!

[sanlyn]

I've been working in virtualdub which has improved things a bit but I'm still getting this rainbow noise/etc in converting. Is it most likely my capture device that's causing the problem? And/or is there any filtering in vdub i can do?

Such noise is common with VHS. It's a mix of player noise and tape noise. Some capture devices add to it, some don't. You can filter much of it, but not effectively after conversion to RGB in VirtualDub. You should work in the original YUV colorspace.

In fact it plays fine on the TV directly. Tapes are older, but not too old, like 10 years old. The quality is not fantastic...

Likely that it doesn't play as well as you think, but in any case the noise would be more obvious on a PC and looks entirely different to encoders, which complicated it and make is worse. Encoders hate noise. I'm not familiar with Roxio so can't advise there, but with composite cables there's more noise than with, say, s-video. Sometimes s-video isn't available, but even that won't entirely eliminate rainbows and streaks. But you appear to be capturing in the preferred way to lossless AVI, so that's a start.

Is there some kind of filter I can use, either during capture, or on the AVI file once it has been created?

Yes, but preferably not during capture. Often the noise and chroma filters built into capture software aren't the best choices. Brightness, contrast and saturation are usually the most practical. DNR filters during capture might some solve problems, but they create others. And none are sophisticated enough to clean rainbows.

Repacking tape (rewinding) would be helpful in other ways, though. It allows the tape to be rewound more evenlyu onto the reel, avoiding bumps and irregular feed into the tape path, helping tape run more smoothly over the heads. That in itself often solves some problems, but rainbows are part of the tape itself.

The cleanup you need to do should be in YUY2 and/or YV12 in Avisynth. There are many plugins designed for these problems. But we can't advise in detail from still images. It's better to post a few seconds of your problem AVI, something containing movement (black leader doesn't count, as leader tape always has video junk in it). You can cut a few seconds of the unprocessed AVI in VirtualDub. But before saving it go to "Video" -> "direct stream copy", then save as AVI.

[lj01]

thank you for the reply! i really appreciate the help!

I can post a snippet later today for a look-see, thanks. On the first point - is that something I set in the "color depth" section of vdub before capturing? If i recall that setting was defaulted to 24-bit RGB (888)...is there something else I should set that to? Or do I specify that YUV somewhere else prior to capture?

Unfortunately, the Toshiba does not give me the option of S-Video out but there is a composite-to-Svideo cable I can purchase - would that be helpful or useless?

[sanlyn]

If you refer to VirtualDub capture, you should be using YUY2, not RGB, and add Lagarith or huffyuv for compression. Once you set those parameters in VirtualDub capture, they should still be there the next time you open the captur window (but I always check anyway. Video engenders paranoia!). With normal VirtualDub processing, opening VirtualDub without capture reverts to uncompressed RGB24. You can modify that default in VDub's settings, but I don't do it because I don't always use the same color depth or compression for normal output.

Do not use cheap s-video adapters. They're godawful, and worse than normal composite.

[lj01]

awesome. Is this where I change it?

[sanlyn]

Decompressor format = "Autoselect".
Output format to compressor/display="4:2:2 YCbCr( YUY2)"

Then go to "Video..." -> "compression...", set to Lagarith or huffyuv . If huffyuv, it defaults to YUY2. If Lagarith, use its "Configuration" button in the lower right corner and set to YUY2.

Then go to "Audio..." -> "Compression..." It should default to "no compression (PCM)".

To start the capture, press "F6". To stop, press "Esc". I use those keys instead of the top menu -- my mouse likes to hit the wrong command now and then! ! ! ! !

[lj01]

Gotcha - so it doesn't matter what i set on that other screen i take it. here's an extreme example, it comes from one of the original WMM captures i did. the problem is a little better but in general still exists.

does the line at the bottom of the screen mean anything? i notice it's not on VHS tapes that i have in my collection from the 1980s.

thanks again for all of your help.

[sanlyn]

Well, thanks for the sample. Can't really advise all that much. There are indeed some filters that can help a lot...but I wouldn't try them on a previous encode that's already been processed with hard-telecine intact, is oversaturated, has badly crushed colors, and was encoded at too low a bitrate for trying to clean up the artifacts that were added to the noise.

Frankly, that looks like damaged tape. But surely they can't all be damaged in that way. If this noise appears on TV playback direct from your tape player, it's either on the tape or in the player. You could try another player and see what happens.

The noise at the bottom is head switching noise. It's thicker at the bottom on some players than on others. Often it's not seen on TV because it usually falls in a TV's overscan area. It's usually cropped off and the image is centered with new borders to restore the original frame size.

[lj01]

sorry - that was one of my original captures that i quickly encoded just to post up here. I'll do one from vdub with the settings you recommended (i'll get the same footage) and you can see how it has improved - i just wanted to post the really bad one so you could see an extreme example of the problem.

i don't think it's the VCR because other tapes play alright. And I don't think it's the tape as this looks reasonably normal on a TV.

Let me get a quick sample of version 2 and I'll post here shortly.

[lj01]

ok, here's sample from vdub, encoded (quickly) with avs2todvd. As you can see, it's much improved. it seems very interlacy on my computer but i think that ends up looking fine on the dvd player. i ramped up the "noise reduction" on vdub but didn't apply any filters or anything.

are there any filters i can/should apply while capturing and/or any i can/should build into the avisynth script when encoding? or is this maybe as good as I'm going to get on this particular project?

thanks again for all of your great advice!

[sanlyn]

Encoding fast-action video at a stingy 4000 bitrate tells why it falls apart when the action gets going. This is also hard-telecined, although the opening commercial looks like plain progressive. It would be better to just leave it as-is. You won't gain by trying to clean it up and encode again, as you've already lost a lot of data and the motion noise and bad frames can't be repaired.

Video with problems like these should not be directly encoded. They have to be cleaned up in YUV first, then perhaps some touch-up in RGB (if needed), and only one encode.

[lj01]

My intention would be to clean it up prior to the encode - the only reason i encoded what I had was to be able to post up here for a look, the raw AVI was 122MB so I encoded so it could be posted - this is not intended to be the finished product.

My question would be - what are the steps i should take on this prior to encoding? You mention cleaned up in YUV first and then touch up if needed in RGB - what/how would I do that?

thanks for getting me to this point thus far - if there's some kind of guide or tool that does the YUV cleanup and/or something that's great. thanks again.

[sanlyn]

A few seconds of standard definition Lagarith-compressed YUY2 AVI would not be a 122 MB file. It wouldn't be 122 MB even if it were Lagarith RGB.

Download the free MediaInfo utility to get a text file of specs about your original AVI capture. You can copy the text readout directly from the dialog window or save the report as a text file, and post the text in this thread.

[lj01]

hmmm...that of course makes me think i'm doing something wrong...it was huffyuv yuy but yes it in fact was 122MB for 9 seconds, which translates into 45GB for the whole 56 minutes I'm needing to capture...that does seem larger than normal. Not sure why but if you have any thoughts let me know.

but i see what you're saying in the sense that my encoding before posting just confuses the matter and that you need to see the raw materials. I'll get the text file up and i'll try to see if i can do something to post the raw file.

thanks again for your help and thanks for your patience.

[lj01]

ok, i captured in lagarith yuy as suggested and that resulted in a smaller file (41MB for 6 seconds) which i am able to upload. Here it is.

I will download the mediainfo to get some more info. Thanks for your help.

[lj01]

ok, so here's what i get on mediainfo:


Complete name : C:\Documents and Settings\My Documents\My Videos\test77.avi
Format : AVI
Format/Info : Audio Video Interleave
File size : 40.6 MiB
Duration : 6s 0ms
Overall bit rate : 56.8 Mbps

Video
ID : 0
Format : Lagarith
Codec ID : LAGS
Duration : 5s 806ms
Bit rate : 57.1 Mbps
Width : 640 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:2
Bit depth : 8 bits
Bits/(Pixel*Frame) : 6.198
Stream size : 39.5 MiB (97%)

Audio
ID : 1
Format : PCM
Format settings, Endianness : Little
Format settings, Sign : Signed
Codec ID : 1
Duration : 6s 0ms
Bit rate mode : Constant
Bit rate : 1 536 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 1.10 MiB (3%)
Alignment : Aligned on interleaves
Interleave, duration : 484 ms (14.50 video frames)

once again, thank you, and i look forward to your thoughts on this. thanks!!

[sanlyn]

Good work! Takes a while, but you'll get the hang of these nutty procedures. Thanks for the effort. Give folks a while to look it over.

[sanlyn]

First quick look: yep, got some problems. This might be difficult to explain, but you can work up a quick demo for yourself.

The sample AVI shows that the vid has pure progressive and progressive+3:2 pulldown (telecine) content. Not unusual. That's the way the original broadcast source was arranged. The commercial is the progressive part, the muppets are film-based source and is telecined. But it's being played back "as if" interlaced, that is, one video head sends one signal and the other head sends another. If you view pure-progressive content and separate the two fields in each frame as if the vid were interlaced, progressive would show two copies of the same image in each drived "field". With pulldown, you'll see some of the images repeat 3 times instead of twice. That's how film shot at 23.972 frames per second gets to be played at 29.972 fps.

To see what your player is doing, open the AVI in VirtualDub. DOn't worry about colorspace conversion, etc., right now, this is just for a view of how the frames are playing back. You're going to use the bob() utility in VirtualDub to "deinterlace" this sample. In a better deinterlace and/or inverse telecine operation we wouldn't use bob().

1. In VirtualDub, load the built-in bob doubler filter.
2. In the bob filter's dialog window, set "Field order" to "top field first"
3. In the bob filter's dialog window, set "Deinterlace method"" to "Bob"
4. Click OK.

In the left-hand Input window you'll see the original video. In the right-hand Output window you'll see the bob'd version, showing you field-by-field for each frame. Use VirtualDub's single frame advance ">" key to view the AVI one "field" at a time. You'll notice that the worst of the streaky noise is in alternate "fields" (the top or "even" fields) -- that adds to the difficulty of cleanup.

Go to frame 245. You'll see some bad distortion for several frames. I don't know where that's coming from, but it's a real problem. You can imagine how much uglier it looks if a decoder gets its hands on video like this.

Do not deinterlace this vid. The first step is to handle the telecine frames.

[lj01]

thanks - before i get started (and you'll probably want to throw a brick at me) - the commercial here isn't what i'm trying to capture, it was just part of the broadcast - i'm really sorry, i just thought that would be a good sample since it was colorful and had a lot of motion. Does the issue above - is that affecting the entire video or is it specific to that commercial? If it is specific to that commercial then I'm thinking i should probably post a sample of the portion of the show i'm actually trying to capture.

sorry about that. i keep making this more complicated than it actually is.

[sanlyn]

Commercials can always be removed. I assumed that you want the muppets segment.

[lj01]

ok, sorry, here's a sample of the portion i'm actually trying to capture, which i'm assuming based on how it was originally broadcast would be different from the other sample - sorry about that. i'll post the mediainfo on this in a second.

thanks again, and sorry for making it more difficult.

[lj01]

and here's the media info on the new sample:

Complete name : C:\Documents and Settings\My Documents\My Videos\test88.avi
Format : AVI
Format/Info : Audio Video Interleave
File size : 28.8 MiB
Duration : 5s 138ms
Overall bit rate : 47.1 Mbps

Video
ID : 0
Format : Lagarith
Codec ID : LAGS
Duration : 5s 138ms
Bit rate : 45.6 Mbps
Width : 640 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:2
Bit depth : 8 bits
Bits/(Pixel*Frame) : 4.949
Stream size : 27.9 MiB (97%)

Audio
ID : 1
Format : PCM
Format settings, Endianness : Little
Format settings, Sign : Signed
Codec ID : 1
Duration : 5s 0ms
Bit rate mode : Constant
Bit rate : 1 536 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 938 KiB (3%)
Alignment : Aligned on interleaves
Interleave, duration : 514 ms (15.40 video frames)

[sanlyn]

It's OK, I can get get MediaInfo from the downloaded sample.
Oops. You beat me to it.
I'm working on my own project at the same time. And you think you have problems!

[lj01]

sorry, i'm making my problems your problems but i definitely appreciate the help. i actually did take a look at my new sample in the "bob" filter method you mention above. of course, i don't understand what any of it means, but the left side shows some major distortion - i'll be interested in hearing what you think.