v68 - Additional locking added to 'duration update' and 'file prefetch' threads and Stop() method, to fix crashes when filter is closed down (probably caused by timeshift buffer files being deleted quickly after graph transitions to 'stopped' state). These locks stall Stop() until threads are in a safe state (no file read activity).

Allowed FFWD speeds modified to remove LAV video decoder limit, and add overall 4x limit for H.264

'FPS from PTS/DTS' logic modified to require minimum count of PTS/DTS in Start() method.