The old logic required an explicit clearing of the lists first and was
prone to overflow the DXVA2 struct in some circumstances.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
The scaling list can be specified in either the SPS or PPS.
Additionally, compensate for the diagonal scan permutation applied
in the decoder.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
