bash-3.2$ beryl
Xlib: extension "XVideo" missing on display ":0.0".
xvinfo: No X-Video Extension on :0.0
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* Beryl system compatiblity check *
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Xlib: extension "XVideo" missing on display ":0.0".
xvinfo: No X-Video Extension on :0.0
Detected xserver : NVIDIA
Checking Display :0.0 ...
Checking for XComposite extension : passed (v0.3)
Checking for XDamage extension : passed
Checking for RandR extension : passed
Checking for XSync extension : failed
No sync extension
4234907 screens detected.
Currently we cannot guarantee that Beryl will work correctly with multiple X screens.
Using the --no-context-share command line option can help.
Please report any success to the beryl developer mailing list. The list can be found at lists.beryl-project.org