This replaces a large number of checks for the second field by
fixing the pointers when they are setup
This should also fix I/BI field pictures
Changes checksums for vc1_sa10143, the file becomes slightly closer
to what the reference decoder outputs
Based on "vc1dec: the second field is written wrong to the picture"
by Sebastian Sandberg <sebastiand.sandberg@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
