Reinsert macro to fix issue 884.

Change 72056 unfolded some macro definitions,
but lost some alternative behaviour required for
high bitdepth encodes.
This causes the encoder to crash, see issue 884.

Change-Id: I8ce4d73c9fe0a3c10ccb86fba210fabc8b2f0ccc
Merge "Reinsert macro to fix issue 884."