Note: checking out 'remotes/upstream/master'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:

  git checkout -b new_branch_name

HEAD is now at 4c552d8... Fix various issues with VBV+threads Eliminate the race condition with interframe row predictors and threads. Recalculate frame_size_estimated at the end of a frame, for improved update_vbv_plan. Some cosmetics.