Proc Amp Theory and Practice
I have a USB-type VHS-to-digital converter.
Inside my capture software, I adjusted the “Proc Amp” settings (quite a bit) to where the onscreen image was pretty good and ready for capture (then to import into a video editing program).
I shut down for the day and came back later. I got everything in place and looked at a test VHS video image ready for capture. The image ---- and the Proc Amp settings ---- were exactly as I had set them the day before (no need to do it all again).
QUESTION: When one adjusts the Proc Amp settings through the capture software, are those settings retained in the capture software program that “remembered” the particular converter device, or are those Proc Amp adjustments/settings applied to the inner workings of the chip(s) inside the USB converted device (such that when I plugged it in the next day those new settings were “in place” from my careful adjustments made the day earlier)?
FOLLOW-UP: Now assume I had a second VHS-to-digital converter. If the original Proc Amp settings were made using device #1 and they looked the same under device #2, then the Proc Amp settings would have been retained by the capture software. However, if the image using device #2 were initially a disaster, requiring all new adjustments, then that would suggest that the Proc Amp settings made using device #1 were retained in the device itself.
OR: Does the operating system (in this case, Windows) come into play here?
+ Reply to Thread
Results 1 to 12 of 12
Last edited by Avagadro1; 17th Aug 2020 at 23:08.
Depends on the card/device, driver, and capture software. Likely, best practices would say to reset & set EVERY time.
However, I find dubious the proc amp feature "IN SOFTWARE".
Where you really want to have a proc amp is in the analog realm, prior to digitization. Only time digital version might be better is if the digitizer is very high dynamic range and floating point so no real data is lost or clipped prior to coding.
The proc amp is provided by the device driver. Settings are stored (or not) in the Registry by the driver.
"In the device driver", ok, I now understand. The settings are in the Windows Registry for that particular device.
So suppose we had two separate analog-to-digital converter devices, thus two device drivers installed. Assume that device one is plugged in and the Proc Amp adjustments are made. Done. Then device number one is removed and the second analog-to-digital converted is connected to the computer. Now the onscreen image is terrible; Proc Amp adjustments are needed, and made.
Question: If the second device is removed and the first device is placed back into the computer, its device driver (the settings being in the Windows registry) are STILL set and ready to go. Is that about it?
May we conclude, therefore, that if one is using the same VHS player on the same computer, further Proc Amp adjustments should not be required?
Around the same time as adding a Hauppauge WinTV DualHD DVB-T2 dual tuner device to my capture PC, any procamp settings I make for my Live2 (plugged into the same PC) are lost as soon as I close the AmarecTV 3.10 config screen. Not 100% certain it was adding the new device rather than some dogsh** win10 update(s) but . . . ! You should be able to test if this happening by choosing some outrageous settings in hue or saturation and see if you keep those settings when you capture. Using the procamp for the Live2 (Hauppauge Cx23100 Video Capture) via Graphedit AFTER I've come out of Amarec's config window seems to work.
Changing the 'default' settings in the registry doesn't seem to have any effect on my system.
Last edited by TimA-C; 18th Aug 2020 at 13:49. Reason: Additional Thought."Well, my days of not taking you seriously are certainly coming to a middle."
Behavior differs with different devices. Some don't remember the proc amp settings from prior use, some do. Some may revert to defaults when the driver is reinstalled.
jagabo, yes I found that to be the case.
I have two capture devices, one holds its settings, the other must be reset with any change to what's going on.
Guess which I be keeping, and which will be tossed!
Well of course the matter of video quality took priority, of which they were the same.
But it was interesting on how on one device making good Proc Amp setting was quite simple, while on the other device a lot of iterative fiddling was needed --- and the latter was the one that did not hold the settings well.
However, in the end I now better understand what the Proc Amp is about, and the importance of a good initial settings before capturing. Final touch-ups to be implemented later in the editing program.
Much to learn.
As with many devices, Windows' default drivers may have fewer features than the vendor's drivers. So check with the vendor if possible.
So much for best practices...