I'll fix quote of my message for you:You are fail:Now confirmed not by nVidia employees, but by nVidia properietary driver documentation. Thank you for this link.The overlay path is guaranteed never to tear, whereas the blit method is classed as "best effort".
The following conditions or system configurations will prevent usage of the overlay path:
- Overlay hardware already in use, e.g. by another VDPAU, GL, or X11 application, or by SDI output.
- Desktop rotation enabled on the given X screen.
- The presentation target window is redirected, due to a compositing manager actively running.
- The environment variable VDPAU_NVIDIA_NO_OVERLAY is set to a string representation of a non-zero integer.
- The driver determines that the performance requirements of overlay usage cannot be met by the current hardware configuration.