Simple colour correction in Avisynth?
 

I've been wanting to improve the colours on my captured videos for a while now as feel like they are a bit muted and dull, but then Panasonic VCR's have pale colours but i like the image quality best out of other VCRs. I don't have a clue how to work the proc-amp on my TBC, and colour correcting in Avisynth seems overly complex, i don't know where to begin.

I know there's probably many different ways of doing it, i just want something similar to SmoothTweak where i can work with a histogram and adjust the colours without clipping them.

Try virtualdub and gradation filter you can work in. Rgb, yuv, lab etc...

More info HERE

What tbc do you have?

Not really, not easy, but not complex, it is the best route. What have you tried so far?
You grab the installer, run, next, next, done you have installer avisynth.
You grab avspmod "download", unzip, launch, done.
Drag and drop you video source to avspmod
Now you have your video in the preview.

the rest is easy, just try different correction plugins with different settings.

If you can't figure out the right settings just post samples and ask for help. Best place to get avs help is doom9.

Good luck!

TBC-3000.

Yeah it's avspmod i use. By complex i mean i don't quite understand how the histogram works in terms of colour wheels and dots, ect or which one is best to use for my needs. I can get my head around SmoothTweak to adjust the brightness and contrast levels as you have to keep within the lines on the top and bottom. I also use the Saturation setting within that script to help boost the colours, but that has the side effect of making the reds too saturated and people's faces too red, so i can only go so far.

I just need something for more general use which i can safely apply across an entire clip to make the colours look a bit better, without having to adjust it for each shot (i'll only really do that with footage i deem more important) as got hundreds of tapes to go through and it's time consuming. I don't mean something automatic, but something i can adjust to keep it within the safe range, and i would skim through the clip/histogram to monitor any clipping, like i do with SmoothTweak.

I got most of the basics down besides colour correction at this stage :laugh:

I might look into using virtualdub for certain tasks, such as NeatVideo which will be needed for my more grainy footage. Can you apply a filter in vdub, save the file then load this file into avspmod and apply further filters/deinterlace before rendering? I would load the AVS file into vdub but it only saves to AVI which isn't ideal.

You can do that, i still do that from time to time (even work with neat)
You just have to 1: load the filter 2: save in a vdscipt your Vdub filters settings 3: open that vdscript with notepad and copy /paste it (for the filter you want )

the script would look like this:

Not true. VDub2 has native x264 export support. I use it all the time.

I do exactly that: QTGMC etc in an AVS then bring the AVS into VDub, apply Neat (and crop&resize :D), then export H264+AAC.

That's excellent! I've just been tinkering around with the colour correction in Premiere Pro and i find it so much easier to use. Is there a way to import your AVS file to Vdub, apply Neat, save the VD script and import this into Premiere for colour correcting?

I'd just import the AVS file into Premiere but i'm not sure how to do this, and i only have Neat in Vdub. Otherwise i'll have to export it as a lossless AVI and correct it in Premiere.

@Master Tape

you can't* import avs scripts in premiere. But what you can do is, encode the .avs file first with a lossless codec to a normal temporary video file, then import that video file to premiere pro.

It is not so complicated if you check the small part in the manual that introduces the front panel. You pick the channel you plugged your input to, then + or - the parameter you want to modify. As a start, Do not go to far from 0, I find -2 to 2 to be a reasonable range based on my limited experience, but I am not an expert. This is just my personal observation.

*: well, you can, but it is a bit hacky, use the workaround

It'll be lagging (waiting) like crazy, i've been there before. Better to encore in avi lossless first. But to answer the question you can use a frame server (Pismo File Mount.... is it?), it works for sony vegas (using a convertorgb24() line at the end of your script indeed), pretty sure you can with premiere aswell

A small add-on to what themaster1 showed earlier in Avisynth scripting, there is an Avisynth native RGBAdjust command. As of this posting, the avisynth.nl site seems to be down, which would have more documentation and show more of the available arguments to that function. If the site isn't available, perhaps the install has some included documentation.

But just a tiny example would be

ConvertToRGB32(matrix="Rec601",interlaced=true)
RGBAdjust(r=1.04,b=0.93,dither=true)

This would increase the red a little bit, and would reduce the blue a little bit. There are other arguments not in this example that do different kinds of red, green, or blue adjustments.

Of course, something like gradation curves is more advanced than RGBAdjust. It maybe somewhat akin to Levels (RGBAdjust) vs Curves (Gradation Curves) adjustments in Photoshop. It depends on how much control you want.

Or, if you want to do hue adjustments instead of RGB type adjustments, there is the Avisynth Tweak function.

An example would be

ConvertToYV16(interlaced=true)
Tweak(hue=-5,sat=1.30,coring=false,dither=true)

This would rotate the colors (as viewed on a Vectorscope available in either Avisynth Histogram or in Vdub Color Tools plugin) a bit in the counter-clockwise direction to perhaps reduce the red cast in the skin, and would increase the color saturation. A positive hue value rotates clockwise. A value of less than 1, say 0.8, would reduce the saturation. If you want to selectively make an adjustment with Tweak, there is the startHue and endHue arguments to say what range on the color wheel you want to apply your adjustment to. The Avisynth help for Tweak has a table for hue values, I think.

Whether to use RGB type adjustments or Hue based adjustments depends on what a Vectorscope shows you. If you have corrected neutral colors with RGB, but still think the skin tones are too red or blue, try adding a hue adjustment to rotate the colors closer to the area of the scope where skin tones should be (of course also use your eyes on a color accurate monitor). Hue doesn't really fix neutral colors, they are in the center of the scope and don't change much with rotation on the color wheel. But other colors could benefit from a hue adjust if you think they are still off after getting white, black, or gray colors corrected.