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<[email protected]> |
On Sunday, January 17, 2021 at 4:02:24 PM UTC-5, Paul wrote:
> [email protected] wrote:
> > I really like the VLC player but my screenshots keep coming as solid green.
> > I unistall the player then reinstall. Screenshots work a few days then go green again. I'm getting ready to delete VCL forever. Seems related to Windows update (Ver 10). I also often get error messages when I use my GOM player screenshot. The error # is 0 x 80070057.
> > Thanks
> > Gary
> Are you using Windows 10 "snippingtool.exe" ?
>
> To show the basic principle, there is FFMPEG and its "gdigrab".
> It has the ability to capture from the regular graphics plane.
> To place graphics in the regular graphics plane, "disable hardware acceleration".
>
> There are two other graphics planes. There is VMR7/VMR9 for
> video playback, and they would have been popular for video playback
> in a previous generation. This would be the DirectShow and KCodec Pack
> path. Attempting to capture them would likely give a green rectangle.
>
> The third plane, is 3D capture in games. There is some apparent
> difference between "windowed" games and "full screen" games. This
> too makes a difference to the "surface or plane" of capture. NVidia
> provides in-game Shadowplay??? to capture some of that. I've never
> tried this plane, limiting my capture to the front plane only
> (unaccelerated).
>
> There are a lot of rules to remember.
>
> Windows 7 is the last full-service OS. You could buy a copy of the
> "FRAPS" third party product, and capture everything. FRAPS cheated
> by injecting a DLL in every program folder, and the filter driver
> (at a guess that's what it amounts to), it intercepts graphics
> calls, and it records graphics calls rather than pixels as such.
> That's how it was able to do such a thorough job. But the author of
> that, lost the battle with Microsoft - FRAPS could never be made to
> work with Win8/8.1/10 so the author stopped selling it.
>
> Windows 7 allows recording at 60FPS.
> Win8/8.1/10 has a capped recording rate of 30FPS.
>
> For lowest latency and jitter, you disable Aero effects.
>
> The graphics business has been working on a "secure enclave" hardware
> capability for some time, and this too is intended to prevent memory
> copying from a graphics card. All that has to happen, is some Hollywood
> DRM cuts in, requests security, and then a gdigrab method won't work
> (because for the front plane, it's just taking copies of the double buffer).
>
> Another thing you might have noticed, is the VGA connector disappeared
> from new video cards. This completes the route of "analog bypass". Without
> unencrypted analog output, many attempts to do external capture of
> monitor content are thwarted. Hollywood has won. Sneaky, eh?
> First the YPbPr analog coax cable output disappears, then they
> set to work setting the VGA connector on fire. Villains.
>
> With the analog hole closed, HDMI or DisplayPort can use HDCP (encrypted
> digital stream), to thwart these types of cards. In their heyday, this
> class of card was around $100 each. You want the units with passthru,
> two HDMI connectors, one HDMI-in, one HDMI-out, and then the
> capture device can be put "in-line" with the monitor output you
> want to capture. This capture concept is also available in USB3
> capture box format - however, you need the "best-in-class" USB3
> for that, it must be chipset USB3, not add-on chip USB3. One of
> the USB3 products actually has a "benchmark" of sorts which will
> declare your USB3 port "a loser" for you :-) This is why I
> selected some PCI Express cards to demonstrate the concept, as
> the developers can select a decent number of PCI Express lanes
> as needed. If a x4 interface is needed, they'll just put an
> x4 connector on it.
>
> https://www.amazon.com/Elgato-Game-Capture-HD60-Pro/dp/B014MQIVPS
>
> https://www.amazon.com/Elgato-Game-Capture-4K60-MK-2/dp/B07VWXCXM7
>
> If your OS uses HDCP, the earlier version of HDCP was cracked,
> as the keys leaked for it. (Thus there have been HDCP strippers
> shipping from China in disguise as "buffers". You put a stripper
> plus the capture card, for example.) But that stopped
> when HDCP 2.1 or so came out, as that one might not be cracked yet.
> Capturing an HDCP monitor cable signal gives "colored snow" as the
> only object captured. No recognizable image at all.
>
> *******
>
> Summary: Try to use another OS. Win7 is a nice choice.
> Try to disable hardware acceleration in the things you do. (Prefs:Tick Box)
> Don't really expect screen capture to work worth a damn in future.
> Go hardware capture for some fun.
>
> I wouldn't be too quick to condemn the application developers,
> because they have to know all the above inside-out, to stand
> a chance of making anything work. And as Windows 10 is a rolling
> release, the feature they just made work, could be "broken on Tuesday".
>
> Paul
Thanks very much.