Protect previously shown frame from immediate reuse by decoder.

It happend that the previously shown frame was still on screen
while the decoder reused it already and the result was a mixed
picture on screen.
Protection is easy: just keep a reference to previously shown
frame and it cannot be reused by the decoder until a frame
duration has passed which should be sufficient to see the
current frame on screen.
Such referencing has already been implemented although it was
not used for deinterlacing. Therefore it had been disabled to
get an additional frame for decoding in coping with dropped
frames.
The change reenables referencing the previously shown frame.

0 files changed, 0 insertions, 0 deletions