The ref's scale_factors are set at frame level, and then copied for
each partition block. Since the struct members are mostly constant,
this patch separated the constant and non-constant members, and
reduced struct copying. This gave 0.5% ~ 1.4% decoder speed gain.
Change-Id: I94043bf5a6995c8042da52e5c661818dfa6f6d4c
It is possible to have invalid scale factors and not access them
during decoding. Error is reported if we really try to use invalid scale
factors.
Change-Id: Ie532d3ea7325ee0c7a6ada08269f804350c80fdf