Hi,
In trying to achieve 30 fps screen recording on Wayland, I've mapped DRM dumb buffers to 3 framebuffer IDs that I found using modetest. I've gotten this to work, however my resulting video has significant tearing. I figure I am not capturing the dumb buffers in sync with Wayland/EGL updating them. I tried to utilize the DRM_IOCTL_WAIT_VBLANK, but this only blocks until the next VBLANK (during which buffers are updated AFAIK) ; I want the time when the buffers are not being modified so I can safely capture them and feed into my Gstreamer pipeline.
Does anyone know of a way to access the raw Vsync signal in a userspace application (QT)? Any other tips/solutions are welcome.
Thanks,
Vishal
