Proc Amp Controls

[chris319]

I am looking for a capture device which will accept an HDMI output from a camcorder. I need it to expose the full set of video proc amp controls, or at least "brightness" (gain), gamma and "contrast" (lift/setup/pedestal/black level).

I have an Elgato Cam Link 4K which is cheap but only exposes brightness and contrast in OBS.

Any ideas?

Thank you.

[Alwyn]

Not sure if you mean a physical proc amp but on every HDMI digitiser I have, ranging from a $15 special up to a Startech USB3HDCAP, Gamma is greyed-out on the software proc amp panel.

[chris319]

Not sure if you mean a physical proc amp but on every HDMI digitiser I have, ranging from a $15 special up to a Startech USB3HDCAP, Gamma is greyed-out on the software proc amp panel.

No, not a hardware proc amp.

Is gamma adjustable in OBS? I can't find any controls for color correction other than a webcam control which, of course, has gamma grayed out.

[Alwyn]

On further investigation, you can indeed.

RC on your source device, choose Filters. Click the lower + sign and click color correction, then OK. The color correction options and sliders, including Gamma, show up.

[chris319]

On further investigation, you can indeed.

RC on your source device, choose Filters. Click the lower + sign and click color correction, then OK. The color correction options and sliders, including Gamma, show up.

I did all that. I get something called "Effect Filters". Clicking on the "+" sign brings up a list of audio filters (3-Band Equalizer, Compressor, etc.). Nothing for Color Correction.

OBS Studio v 29.0.2 (64 bit)

I found this:

https://learn.microsoft.com/en-us/windows-hardware/drivers/stream/video-processing-amp...ier-properties

[Alwyn]

You're clicking on the + for Audio/Video Filters. Go down a box to the Effect filters area:


[Attachment 70386 - Click to enlarge]

In this example, I've already activated the Color Correction filter.

[chris319]

The problem I was having was that the "+" sign for the Effect Filters was completely hidden by the task bar (720 x 1280) which is a bug as far as I'm concerned. When I moved the task bar to the left of the screen the "+" sign was revealed.

There is plenty of screen real estate to shorten that window by 40 pixels so that the task bar doesn't cover an important part of the user interface.

Thank you for your help.

[Alwyn]

My pleasure Chris.

[VHSvideocapture]

Where should the proc amp levels be kept to when it comes to numbers?
What if the histogram is showing some red?
Is that a bad thing? Can it be fixed after capture or does that mean we have to recapture the whole thing?
If we do adjust that red then the brightness goes. To high meaning over exposed whites.

Its difficult to set procamp because some capture cards don't show proc amp in levels and you have to go into video settings and you can't view proc amp in settings I've hread of some users using graphstuio is that a safe download? I've read you have to download something else to get it working? I don't like downloading stuff because of viruses, I only download the absolute essentials.

[Alwyn]

I've hread of some users using graphstuio is that a safe download?

Yes, provided you download it for VideoHelp.

I've written some guides on this subject on my website:

Set the Brightness and Contrast Using the Virtual Dub Histogram

Realtime Control of Proc Amp settings with Graphstudio

[themaster1]

Its difficult to set procamp because some capture cards don't show proc amp in levels and you have to go into video settings and you can't view proc amp in settings I've hread of some users using graphstuio is that a safe download? I've read you have to download something else to get it working? I don't like downloading stuff because of viruses, I only download the absolute essentials.

graphstudio is a developper software to troubleshoot / debug possible bugs with a specific A/V cards drivers / rendering filters etc...
Don't be surprised it crash on you for no reason when you record and then complain about it

[Alwyn]

I have never had Graphstudio crash on me when using it to access the proc amp.

[The_Doman]

graphstudio is a developper software to troubleshoot / debug possible bugs with a specific A/V cards drivers / rendering filters etc...
Don't be surprised it crash on you for no reason when you record and then complain about it

You can also use some other capture program which lets you access the procamp settings during capturing.
I use the Amcap tool for that

Here using it to adust the video standard "on the fly" to SECAM B for PAL60 capturing.

[Attachment 78362 - Click to enlarge]

[Alwyn]

@Doman, yes, but Graphstudio will allow you to access the proc amp when you're setting the Brightness and Contrast using the VDub histogram.

[VHSvideocapture]

graphstudio is a developper software to troubleshoot / debug possible bugs with a specific A/V cards drivers / rendering filters etc...
Don't be surprised it crash on you for no reason when you record and then complain about it

I've just downloaded it now I need to learn how to set it up.

I just want to see proc amp so I can set brightness and contrast and stop it from clipping

[VHSvideocapture]

You can also use some other capture program which lets you access the procamp settings during capturing.
Here using it to adust the video standard "on the fly" to SECAM B for PAL60 capturing.

I am use to virtuldub 1.9.11 and everybody uses it for capture, some also use it for basic clean up
I already have virtuldub set up and running I don't want to add more software but thanks so much for helping

[VHSvideocapture]

I've hread of some users using graphstuio is that a safe download?

Yes, provided you download it for VideoHelp.

I've written some guides on this subject on my website:

Set the Brightness and Contrast Using the Virtual Dub Histogram

Realtime Control of Proc Amp settings with Graphstudio

Download it with no issues.
How do I configure it?
Alwyn please make another YouTube video on how to configure it so other people can learn as well thank you for being si helpful

[Alwyn]

Read my guide; a few clicks and you'll be in business.

You can also use some other capture program which lets you access the procamp settings during capturing.
I use the Amcap tool for that

The Device properties for the GV-USB2 are greyed out during capture, I can't adjust the proc amp during capture with Amcap.

[The_Doman]

@Doman, yes, but Graphstudio will allow you to access the proc amp when you're setting the Brightness and Contrast using the VDub histogram.

Using the Amcap example shown, i can change the procamp settings also during capturing/monitoring with VDub/Amarec and a Dazzle DVC100.
Just ignore the error "device in use" when starting, you still can access/change the procamp settings.

The Device properties for the GV-USB2 are greyed out during capture, I can't adjust the proc amp during capture with Amcap.

Ok, possible it depends on the capture device/driver?
Will take a look later at GraphStudio too.

[Alwyn]

The USB Live 2 also cannot display the proc amp in VDub with the video showing. The preview screen goes blank when you go the to Capture Filter.

The beauty of Graphstudio is that it is totally independent of the capture program; you can have it sitting off to one side of the desktop while you fiddle with the capture program. You can also save your Graphstudio setting as a .grfx file so you simply double-click it to open it next time.

[lollo]

graphstudio is a developper software to troubleshoot / debug possible bugs with a specific A/V cards drivers / rendering filters etc...
Don't be surprised it crash on you for no reason when you record and then complain about it

For testing and comparison purposes, I intensely use GraphStudioNext for capturing and never experienced a (inherent) crash

[VHSvideocapture]

The Device properties for the GV-USB2 are greyed out during capture, I can't adjust the proc amp during capture with Amcap.

Same issue it says something like level driver not found

[VHSvideocapture]

The USB Live 2 also cannot display the proc amp in VDub with the video showing. The preview screen goes blank when you go the to Capture Filter.

The beauty of Graphstudio is that it is totally independent of the capture program; you can have it sitting off to one side of the desktop while you fiddle with the capture program. You can also save your Graphstudio setting as a .grfx file so you simply double-click it to open it next time.

I will take a look at your guide later on and get it set up tomorrow.

The Avermedia EZ maker7 capture card does let you adjust proc amp in levels
Go to video and levels option in vd , it works on some capture cards but not on GV-USB2
it is disabled

[VHSvideocapture]

Read my guide; a few clicks and you'll be in business.

Had a look on the website and I've taken screenshots.
But it says

Save the Graphstudio setup using File>Save as Graph (GRF). You can then use that GRF file to quickly re-open the graph next time. For users of AVISynth, the GRF file can be used as a source video, then the AVS can be opened in Media Player Classic to display a real-time Histogram for use with AmaRecTV. This only works for some digitisers. For example, it will work with the Startech USB3HDCAP, but not the GV-USB2

You can't save the settings you have to do that each time you capture

[Alwyn]

Go to video and levels option in vd , it works on some capture cards but not on GV-USB2
it is disabled

That is why you use Graphstudio: it gives you access to the proc amp when the capture program won't.

You can't save the settings you have to do that each time you capture

What I meant was that you can save the GRF setup: you don't have to go through the process of inserting the filter for the digitiser each time.

Whether or not the actual proc amp values are saved is up to the driver of the digitiser. The GV-USB 2 and USB Live 2 proc amp settings are retained. However, you may well find that the settings used before will not be appropriate for the next tape anyway and will need adjusting.

[VHSvideocapture]

That is why you use Graphstudio: it gives you access to the proc amp when the capture program won't.
What I meant was that you can save the GRF setup: you don't have to go through the process of inserting the filter for the digitiser each time.

I've got it working fine with VD went to menu fitters insert found my GV-USB2 from the list on the left hand side, had 3 entries I just picked the first one it was showing as a wmd device not sure if that matters or not because vd is picking it up as a direct show device, then right click small box that comes up click properties and it gave me proc amp, If I click save I will not need to add the GV-USB2 from the filters? file save and give it a name like GV-USB2?

I set the proc amp values following your YouTube video, I got the histogram blue waves in the middle BUT the whites look over exposed when I did that, can this be fixed afterwards in VD bulit in HSL plug in filter that reduces brightness and contrast?

Will doing this crush black levels or over expose white levels?

Whether or not the actual proc amp values are saved is up to the driver of the digitiser. The GV-USB 2 and USB Live 2 proc amp settings are retained. However, you may well find that the settings used before will not be appropriate for the next tape anyway and will need adjusting.

I can understand even if it did it would be kind of pointless as every tape has different levels and different scenes some light some dark.

[Alwyn]

I've got it working fine with VD went to menu fitters insert found my GV-USB2 from the list on the left hand side, had 3 entries I just picked the first one it was showing as a wmd device not sure if that matters or not because vd is picking it up as a direct show device, then right click small box that comes up click properties and it gave me proc amp, If I click save I will not need to add the GV-USB2 from the filters? file save and give it a name like GV-USB2?

Yes, give it whatever name you like. Mine's called "GV-USB2 Graph.GRF". When you open that GRF file again, the little box will appear straight away and you can right-click>Properties>Proc Amp tab.

I set the proc amp values following your YouTube video, I got the histogram blue waves in the middle BUT the whites look over exposed when I did that, can this be fixed afterwards in VD bulit in HSL plug in filter that reduces brightness and contrast?

You can lower the right edge of the histogram to reduce the whites if you think they're still too bright. You can always increase the whites afterwards, but you can't recover blown-out whites. Same with the blacks on the left end of the histogram. I use the "Colormill" filter for post-cap adjustments. There's also a "levels" filter which is still a bit of a mystery to me. You can of course adjust the levels post-capture with AVISynth if you're into that.

I think the term "crushing" comes from being out of bounds. You can be "in-bounds" OK and fix that; you can't fix out of bounds/crushing.

[VHSvideocapture]

Yes, give it whatever name you like. Mine's called "GV-USB2 Graph.GRF". When you open that GRF file again, the little box will appear straight away and you can right-click>Properties>Proc Amp tab.

Will do that

You can lower the right edge of the histogram to reduce the whites if you think they're still too bright. You can always increase the whites afterwards, but you can't recover blown-out whites. Same with the blacks on the left end of the histogram. I use the "Colormill" filter for post-cap adjustments. There's also a "levels" filter which is still a bit of a mystery to me. You can of course adjust the levels post-capture with AVISynth if you're into that.

I think the term "crushing" comes from being out of bounds. You can be "in-bounds" OK and fix that; you can't fix out of bounds/crushing.

I adjusted everything and started capture when the blue histogram wave was set the middle but that give me extra brightness but if I reduce the brightness making it look natural it would go in the read zone on the left edge.

Do we know what the legal levels are in terms of numbers? I think default is ser to everything 128.
Is it bad if it goes 20 percent to the red? I was hoping it would be ok to let it go into red and adjust brightness contrast in VD bulit in filter after capture, difficult if details are going to be lost.

The levels tab is a shortcut for setting the proc amp levels itvl doesn't work with GV-USB2 it says something like no level driver available for this device, works on others.

[Alwyn]

I adjusted everything and started capture when the blue histogram wave was set the middle but that give me extra brightness but if I reduce the brightness making it look natural it would go in the read zone on the left edge.

By brightness, do you mean bright whites? In that case, lower the contrast (right edge of histo). That will probably require to slight increase in brightness to keep the left edge legal.

Do we know what the legal levels are in terms of numbers? I think default is ser to everything 128.

Will change for every tape.

Is it bad if it goes 20 percent to the red? I was hoping it would be ok to let it go into red and adjust brightness contrast in VD bulit in filter after capture, difficult if details are going to be lost.

Yep, keep out of the red. You can adjust/boost the levels in post, but you won't get back any overwhites or blacks.

The levels tab is a shortcut for setting the proc amp levels itvl doesn't work with GV-USB2 it says something like no level driver available for this device, works on others.

Not sure what you mean; what program are you in here?

[VHSvideocapture]

[QUOTE=Alwyn;2733518]
By brightness, do you mean bright whites? In that case, lower the contrast (right edge of histo). That will probably require to slight increase in brightness to keep the left edge legal.
[\QUOTE]
Yes it seems that way.
This can't be sorted out after capturing?
Will I need to recapture

Will change for every tape.

Yep, keep out of the red. You can adjust/boost the levels in post, but you won't get back any overwhites or blacks.

Even if that means whites blowing out

The levels tab is a shortcut for setting the proc amp levels itvl doesn't work with GV-USB2 it says something like no level driver available for this device, works on others.
Not sure what you mean; what program are you in here?

VD has a level option in the menu it gives you access to brightness and contrast without having to go into proc amp