How to remove colored bar on side of Hi8 tape?

[oddmykyta]

While capturing via gvusb2 ive got that greeny coloured bar on the right side due to overscan like lordsmurf said.
i will attach the sample comparison video between my old crappy usb stick and my gvusb2.

the question is how could i get rid of that without losing information and cropping the frame? I mean, black bars and some noises on the bottom are completely ok but it seems like something strange and i have no clue how could i solve this. Any suggestions/tricks with filtering whatsoever? thx

By the way, this bar´s coloring is always random depending on each frame..

[Aya_Rei]

The bar on the bottom image? That to me looks like regular over scan noise that should be cut out by masking it with a black bar. Usually it only covers around 6 to 8 pixels on the Y axis. So you aren't chopping away that much picture information. Besides, a regular TV wouldn't even show that part of the image anyway.

I can't quite seem to spot the bar on the right side, but if there is one, it might be best to mask that as well.

[latreche34]

The OP said clearly on the right side of frame.

[oddmykyta]

thanks for claryfying. right side of the right side of sample video i´m attaching other examples below.

[Aya_Rei]

Ah, now I see it clearly on the boat image. Was rather hard to spot on the hand image so that's why I thought the OP was talking about the bottom overscan area, sorry.

It looks to affect around 18 pixels or so of the right side. While I'd just mask it if I were you to do a quick, easy solution. I'm unsure of a better solution here to tackle this issue. Maybe Balance Borders or Edge Cleaner using Avisynth?

I do apologize if I'm not being that useful here, though

[oddmykyta]

will try this out! thank u for ur feedback

[keaton]

The forum's recommendation is to post a lossless avi file to work with (typically huffyuv). The forum has posting guidelines somewhere. Didn't have the time to track them down. Without that, others are not able to help as much because they don't have a proper sample to play with in Avisynth, for example, to see if there idea can work.

That color bar on the right edge could be one of two things: 1.) a general chroma shift problem in one or both color channels (the U and/or V channels in a YUV video file), 2.) a lack of color or color error only on the right edge of the camera sensor that shot the video or on your playback machine, but the rest of the frame has no issue with chroma shift. For scenario 1, Avisynth's ChromaShift function could be used. See http://avisynth.nl/index.php/ChromaShift for details. For scenario 2, Avisynth crop and addborders functions would be used to crop it out and add pure black in it's place to preserve the correct video dimensions.

Both of those scenarios were discussed in this thread from 3 years ago. See https://www.digitalfaq.com/forum/vid...ure-noise.html My initial reply in Post #2 shows how to handle situation 1 or 2. The first step would be to just try the chromashift part without the overlay to see if the rest of the frame still looks OK color wise and new color halos don't appear on the left or right edges of other objects in the frame. Also, in post #11 of that thread, I posted a slight tweak to the first example to shift things a couple more pixels to the right. Keep in mind the example video in this thread was 720 columns wide, so the magic numbers in that code assume 696 + 24 for 720 columns total. Adjust accordingly for whatever dimensions your video is and the size of the color bar you are trying to fix.

Hope this helps.

[oddmykyta]

I will surely try this methods! Thank you. Should i post loseless avi for you? just asking. thx again.

[keaton]

You're welcome! No need to post lossless for me for this particular thread. The thread I referenced has a lossless avi example that I'm assuming is similar enough to the problem seen in your attachments. I would download the lossless file in that thread and play with it using the example code in order to understand what that code is doing. Then you can try tweaking the same code to your situation and see if it resolves the issue. If not, then the method of cropping off the right edge and adding a black border to replace it would seem to be the only correct answer.

[oddmykyta]

Sure. here it is though i also assume that something is not right about the colors. the image is kinda wiped out. on my camcorder im seeing much more satured blue water and sky. So it could be due to chroma channels as u mentioned before. i would be pleased by ur feedback. loseless raw (interlaced) avi using UT is attached.

[keaton]

Took a quick look at it, and loaded an .avs file with the following into Virtualdub with Filters "Camcorder Color Denoise" (aka CCD) and "Color Tools" using the Vectorscope view. The Color Tools filter should be last on the list of added filters, and is only for analysis when tweaking saturation (so the value is not pushing color beyond the legal limits in the Vectorscope) or doing other color things like color correction. Be sure to disable or remove Color Tools from Filters before saving the resulting AVI. There's plenty of posts in the forum about CCD, nothing more to say about it here.

From this clip, I couldn't see that using ChromaShift created any new problems. You'll have to do this with more video and see if you notice the ChromaShift introducing new color problems around the left or right edges of objects with certain colors. If so, don't use ChromaShift and Overlay. Instead, just crop and addborders to replace the right edge with black border.

If you don't like black borders, you can remove the last addborders call and use something like Spline36Resize or whatever you like to get it back to the desired resolution. Search the forum for plenty of discussion on that.

Also added some comments about histogram and levels. It is best to capture your video within legal YUV range before getting to this phase. But if not, at least do a Levels command to get video back into legal gamut. Plenty of prior forum posts about all of this. So search forum about the Levels command. Use the Histogram command as shown below to help when using Levels. I should note that I had to convert from UT to Huffyuv to look at this video. So perhaps that conversion is what caused the levels to change. So check this yourself with the Levels command commented out and the Histogram command uncommented to see if you are in fact outside the legal range. Search the forum or avisynth.nl about the Histogram command and what the results mean.

v=AVISource("test edge bars.avi")
AssumeTFF(v)

a=last # save current video for use later

# Shift original clip chroma (both U and V channels) right 14 columns, then keep only the right most
# 26 columns (the 14 with the color issue and the 12 black columns to the right of that), fill the
# remaining columns to the left of that as black
b=ChromaShift(C=14).crop(694,0,0,0).addborders(694,0,0,0)

# Make a copy of the original clip with the right most 26 columns cropped off
c=a.crop(0,0,-26,0)

# Overlay the copy of the original (c) on top of the Chroma Shifted copy (b) with full opacity
Overlay(b,c,0,0,opacity=1.0)

# Crop off bottom 10 rows to remove head switching noise. Crop off top 6 black/gray rows, then add 8 rows on top and bottom to preserve the original resolution and center vertically 
# Also crop off 4 pixels on left edge and 8 pixels on right edge, then add 6 rows on left and right edge to preserve original resolution horizontally
crop(4,6,-8,-10)

# Adjust Luminance (Y) channel so levels are within legal 16 to 235 range.
# The Histogram command below shows the video was going from 0 to 255 when the Levels command was not used.
# This would be an issue best fixed in capture, because the detail will already be lost if you don't
# capture video in the legal gamut of YUV (16 to 235).
# But if levels cannot be resolved in hardware capture phase, this is the only option left
# to ensure legal levels when authoring the final video
Levels(0,1.0,255,16,235,coring=false,dither=true)

#Comment out these 2 lines before saving resulting AVI
#Uncomment when doing Levels tinkering above
#ConvertToYV16(interlaced=true)
#Histogram("levels")

addborders(6,8,6,8)

#Increase Chroma Saturation. Note: Doing this can make incorrect color more noticeable. Color Correct with Avisynth or VirtualDub Filters as needed. Color Tools in Vectorscope view or similar filter can help prevent adding too much saturation.
tweak(sat=1.25,coring=false,dither=true)

#If using Virtualdub filters (Video mode set to "Full Processing Mode"), they operate in RGB domain. So convert to RGB.
ConvertToRGB32(matrix="Rec601",interlaced=true)

So, this may be a lot to digest, and may be way more than you were expecting. That's the pro or con, depending on how you look at it, when posting a lossless clip. If you're feeling overwhelmed, understand that there's a lot of details to look at. It's up to you how much you want to dig in and learn. Patience and genuine interest will help a lot if you want to keep digging into some of the topics touched on here. It took me quite a while to understand all the basics. Everything I'm saying here comes from reading this forum and searching through the treasure trove of knowledge it has. I'm very grateful it exists. To me, the time spent was more than worth it. Best of luck to you!

[oddmykyta]

i aprecciate your detailed feedback. im going exactly same way and have read a lot threads till my own first one.
gotta research even more..

just tried your code tho. somehow avisynth doesnt read the chromashift function.. what could be the deal? tried to solve it somehow but im not familiar with coding... thx

UPDATE. my system is x64 so it doesnt run x32 colorshift dll.. now trying to find x64 version. i hope there is one.

one more question, could u post a result after using this code? it would be great. again, thx in advance

[keaton]

The latest file posted to http://www.avisynth.nl/index.php/ChromaShift is 20 years old and only has a 32-bit version of ChromaShift.dll. Although it does have the source code in the attached .zip file. Trying to build it may be an option, if 64-bit won't allow you to use that 32-bit dll file. Otherwise, you'll need to search for whatever the equivalent is in 64-bit Avisynth. Attached is resulting Huffyuv AVI from running this script with Camcorder Color Denoise filter at Level 40.

I also noticed the audio is left channel only. To address this, look at this thread. https://www.digitalfaq.com/forum/vid...o-capture.html

If your capture setup allows it, consider recapture so the video levels are in gamut. Refer to Virtualdub Settings Guide and other forum threads about using a capture histogram. Posts 3, 4, and 5 get into Video and Audio Level monitoring before and during capture. Here's a link to post 3 https://www.digitalfaq.com/forum/vid...html#post45238

[oddmykyta]

Oh god. lets see how far goes my 32 to 64 dll converting. any suggestions about the process? thx

one more question, would u suggest buying some old win7 x32 laptop for the whole capturing process? I mean, i´ve read a ton of info here and everytime everything works better on old systems. But i also saw a thread telling that x64 avisynth is just better in overall. Since it is the only problem i´ve got with capturing, i could close my eyes on other features.
Would u also tell your exact system u are using? i mean what win and x32 or x64. but further details would be also nice to hear. appreciate it.

[keaton]

I don't know much about 32-bit vs 64-bit windows. Sometimes latest Windows can use legacy 32-bit things, sometimes it doesn't. Not much experience with that. I've never used anything other than Avisynth 2.6 in 32-bit configuration. I realize the Avisynth and Virtualdub development has long since moved on to newer operating systems. However, since I've been doing this for a few years in this configuration and all the filters and plugins I've downloaded have handled all the tasks I've needed to do, I have no incentive to look for more modern solutions.

My capture rig is an XP PC with an ATI AIW capture card recommended on the forum using the recommend version of Virtualdub 1.9.11 found on this forum. This is only for capture. I'm generally not a windows person. I use Linux for everything else except this video hobby. But, since the tools suggested by the forum are Windows based, I run XP in Virtualbox for my post work so I can take advantage of modern multicore and higher processing power. I would guess Windows 7 Virtual Machine would also work for the post work.

For capture, Virtual Machines are not expected to work reliably. You need to use the native hardware. I cannot give you advice on what you need. I can only tell you what I use. The forum has it's recommendations. I realize they might be rather dated, because this forum has been around for decades. Unfortunately, the world has moved on from analog video capture. So that can also be a reason why those recommendations haven't been updated.

I realize most probably don't use such old tech for video processing. However, once I've found something that works for all my tasks, I tend to keep using it rather than spending a lot of time trying to upgrade. Virtual Machines are a wonderful way to avoid the problems that come with new operating systems and there incompatibilities with older tech. It can be limiting when the latest versions of some plugins are no longer developed or supported for Avisynth 2.6 32-bit. Thankfully, I grabbed what I needed off the web and archived it years ago.

Sometimes it would be nice to try a newer version, but if the maintainers of a certain plugin don't have good archival control of older versions, I've been able to get by without it thus far. With some of the more advanced tools, sometimes latest is not the greatest, at least in my experience. As always, just one person's experience.

Shocking that something basic like ChromaShift is not available in modern Avisynth. Analog video often has a bit of chroma shift, especially with generational loss of copying from tape to tape. So a basic toolbox to work with analog video should have some way to address this. Just another example of how latest may not necessarily be greatest.

Perhaps the primary users of that are not into analog video processing. I can only speculate. Maybe somebody else can offer some advice on how they do that now with the latest version.

[oddmykyta]

thank you for another reply, but still, as i understood, do you run win 7 virtual machine from ur modern Linux-based pc that has 32bit system for postwork? Asking cause most modern pcs have 64bit. Again, as i understand u applied all the filters to my avi using that virtual machine?

[keaton]

I've never used it, but seems there is another function http://avisynth.nl/index.php/MoveChroma that is listed for Avisynth+ Looks like it has the same feature. It looks like the equivalent of the C option in ChromaShift would be to pass the same value to both Cb and Cr arguments for MoveChroma

For capture, I use XP directly on an old PC, because the capture card only has drivers for XP. For all other work, I have an XP Virtual Machine (in VirtualBox) running on a modern Linux PC. If I were trying to use Win7 in a Virtual Machine, I would install a 32-bit version of Win7 when setting up the Virtual Machine. The file I created was done in an XP Virtual Machine.

[oddmykyta]

Your feedback is much appreciated. Thank you for providing all that info.

[Selur]

BalanceBorders should help with such color derivations at the borders

[oddmykyta]

danke dir! Could you provide a link for this filter? couldnt find by now. thx in advance