Make framebuffer allocations according to the chroma subsamping
factors in use. A bit is placed in the raw part of the frame header for
each of the two subsampling factors. This will be moved in a future
commit to make them part of the TBD feature set bits, probably only set
on keyframes, etc.
Change-Id: I59ed38d3a3c0d4af3c7c277617de28d04a001853
This is like VP8_COPY_REFERENCE, but returns a pointer to the reference
frame rather than a copy of it. This is useful when the application
doesn't know what the size of the reference is, as is the case when
scaling is in effect.
Change-Id: I63667109f65510364d0e397ebe56217140772085
