DV (from VHS/Hi8/miniDV) -> HD. Expand color/luma? Bad idea?

[Colmino]

How are you getting that configuration menu?

Start VirtualDub. Select Video -> Compression. Select Cedocida in the left pane. Press the Configure button to the right.

Interesting. Do these settings then only apply to the codec's usage within Virtualdub? (I had been under the impression that the codec configuration menu would affect the codec's functionality universally.)

[jagabo]

The settings will apply to that session of VirtualDub and remain in effect globally until you change them again.

[sanlyn]

It's a shame VirtualDub can't be used for any kind of corrective work or capture with VHS. Effectively, its habit of expanding 16-235 to 0-255 and screwing up the level extremes make it all but useless for work with VHS->DVD transfers.

Few can afford the price of Sony Vegas and its severe shortage of color corection and noise reduction filters. VirtualDub can be used with NeatVideo, ColorTools, and Gradation Curves plugins; there are no versions for AviSynth nor for Vegas (even if one could afford Vegas, they'd be too broke too pay for additional pricey plugins. Effectively, Vegas and its toys are for the rich). And If anyone again suggests AviSynth noise reduction filters such as Convolution or the usual crowd, I'll bit their nose off; AviSynth's noisy noise reduction are a waste of time and effort.

I'm using VirtualDub with all these aforementioned tools anyway. You can use Avisynth's DecodeMPEG dll to get an AVI from MPEG2, but it doesn't seem to have any effect as soon as the AVI is processed in VirtualDub. Having tried to use Vegas and even a few plugins made for it, $600 seems a lot to pay for such poor color-correction or noise reduction methods. AVI made from VHS tapes look just as bad coming out of Vegas as they do going in.

I've resigned myself to struggling with VirtualDub and the aforementioned plugins, even if it means hours of restoring black and white level detail to 16-235 standards. Vegas was made for DV only, I see no way to clean and convert VHS video with Vegas.

[jagabo]

Feed VirtualDub with AviSynth:

WhateverSource("video")
ConvertToRGB(matrix="PC.601")

That will avoid the contrast stretch.

[sanlyn]

True, jagabo, PC.601 works if all you want to do is look at the vid or do a cut, etc., but as soon as you load 3 or 4 VirtualDub filters, VDub performs the stretch. I do know that NeatVido requires RGB input and that internally NeatVideo uses its own proprietary YUV space for noise reduction. But as soon as NeatVideo or GradationCurves returns the results, VirtualDub has worked the stretch.

It's possible to feed AviSynth those plugins if you wanna write a lot of code, but to get the filter values for a curves plugin you have to use the filter in VirtualDub, save the virtualDub filter settings, and copy tons of that code into an AVS script. But the 0-235 bug still ends up in the final results. Also possible, if you really wanna spend some time at it, is to frame-serve the plugins thru TMPGenc, but VirtualDub still enters the picture at some point.

Fortunately, TMPGenc Plus 2.5 does render using CCIR.601 by default, but I still have to perform that final step of cleaning up everything between RGB 0-16 and RGB 235-255. It takes some mighty tricky gradation curves to do it, especially with the kind of contrast you get from old VHS videos. With care you can keep the vid from looking pale or washed out. But it's a pain.

As far as noise reduction goes, I can't live without NeatVideo. It makes VHS look as clean (noiseless and mostly artifact-free) as a DVD source, but of course the acutance and color depth aren't there. NeatVideo is able to reduce grain, temporal noise, most head-switching noise and color bands and streaks, etc. I've tried every VDub and AviSynth filter in sight, and none do nearly as well in this respect.

NeatVideo does make a plugin for Vegas. All I need is $$$ for Vegas (!@#$%*), which is out of the question for some time to come. There is no gradation curve equivalent for Vegas. Once you learn how to use VDub's curves plugin, all other color and level controls are obsolete. How else can you fix up the low midtones in VHS (and they are usually awful) without screwing up the darks and brights? I've even taken to using Photoshop's curves exclusively for photos, no other filter compares to that kind of corrective device. You can also chain a series of VDub curves plugins and work in different color spaces (one for luma, one for RGB) at the same time; I've found nothing that can beat that.

By the way: these VHS captures worked in VurtualDub have some pretty grimy blacks, but the luma level (according to ColorTools) seldom falls outside the 16-235 range. I don't know how it's possible for luma to stay straight while colors go haywire, but there you are.

[jagabo]

True, jagabo, PC.601 works if all you want to do is look at the vid or do a cut, etc., but as soon as you load 3 or 4 VirtualDub filters, VDub performs the stretch.

That has not been my experience. If you feed VirtualDub RGB it doesn't have to convert YUV to RGB so there is no contrast stretch. Maybe one of the filters you are using is screwing things up.

If you handle the video this way in AviSynth/Virtualdub you have to enable the "output YUV data as basic YCbCr not CCIR601" option in TMPEGEnc.

[sanlyn]

I hear ya, jagabo, but even though I've corrected the darks and tamed the brights with these filters, I still have a 0-255 RGB that I'm feeding TMPGenc and CCE. Hitting the no-CCIR601 switch makes the video too dull and dim. Yes, you can play with the corrected AVI in AviSynth, but but that screws up my encoders with very unpredictable IRE results. Maybe I should explain what I'm doing with the gradation curves plugin (https://forum.videohelp.com/topic348488.html).

The curves grid is a grid of squares like Photoshop's curves grid. The lower squares map to darks RGB 0-64. The middle two squares map to midtones 64-192. The top squares map to 192-255. I don't see many VHS captures that need help in the 192-255 range, they generally taper off at that point. Most of the work comes in the midtones, especially lower midtones where VHS tends to look, uh, "clogged". Down in the darks theres' almost always a huge peak smashed against the left-hand side of a histogram, especially with Panasonic VCR's.

With a gradation curve you can make overall color changes that affect all 4 areas, or you can play around in a single square without affecting the others. If you work in RGB, you can cure blue highlights without turning the shadows green. Working in YUV or LAB color space, you can brighten or darken areas without affecting RGB color balance.

With any RGB color control I've used, you can add red to cure a blue color cast -- nice flesh tones, but the shadows go brown. You've also brightened the overall image, maybe more than you want. So you can chain another gradation curve in the circuit and use that to work with YUV-luma only; you can tame the highlights and upper mids without washing out shadows or changing overall color balance. That's impossible with the usual RGB, levels, or YUV filters.

Keep in mind, I'm having to do this with certain VHS tapes because I couldn't capture with a proc amp. Macrovision and proc amps on some tapes just don't work; the proc amp introduced semi-transparent gray bars. So I'm capturing bare-back, if you will; oddly, the luma levels stay within 16-235 most of the time, but the colors get screwy. When I can use a proc amp, the darks and other areas are well-adjusted, even in VirtualDub.

The biggest problem is cleaning up that 0-64 RGB range, getting rid of the black peaks by brightening RGB 20-64. I still have to let the 0-16 range go dark, but with gradation curves you can fashion a smooth, fast taper below that range and brighten the 192-235 range without making the video look washed out. The tricky part is adding or subtracting the RGB colors you need, then chaining a curve with a LAB color space to readjust the overall luma to normal. Thankfully you can chain several curves, turn some off, turn some on, and save your curve settings. Almost as good as sliced cinnamon-raisin bread, IMHO. It works, but it sure is draining.