Version .16 is the best yet! The only problem I've noticed so far is that the screen is blanking (due to power management) while the video is playing (at least, it is blanking when playing from the command line).

Tearing would seem to be entirely eliminated - I can't say I noticed a single tear during my testing.

The patched xserver does appear to have a beneficial impact - typically the time taken to output video is reduced by at least 50% when compared with the unpatched xserver.

Excellent work Serge!