use ffmpeg -h filter=deinterlace_vaapi can't get full help information,
the root cause is not setting the flags fileld in options.
Signed-off-by: Jun Zhao <jun.zhao@intel.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This is an ABI change in libva2: previously the Intel driver had this
behaviour and it was implemented as a driver quirk, but now it is part
of the specification so all drivers must do it.
In order to work correctly with the i965 driver, this also fixes the
direction of forward/backward references - forward references are
intended to be those from the past to the current frame, not from the
current frame to the future.
(cherry picked from commit 9aa251c98c)
