codecs: h264decoder: Add support for field-pair input frame
codecs: h264picture: Count only complete complementary field pair for dpb fullness decision
Our DPB implementation was designed as such that allowing
temporary DPB overflow in the middle of field picture decoding
and incomplete field pair should not trigger DPB bumping.
codecs: h264decoder: Add support for field-pair input frame
In case that upstream pushed buffer as a frame unit, not picture
unit for interlaced stream, baseclass should be able to detect
AU boundary (i.e., complementary field pair).
codecs: h264decoder: Remove unused private variables
... and reset() method to clear internal status at one place