Hyunjun Ko authored Feb 13, 2018 and Sreerenj Balachandran committed Feb 13, 2018

1\ In decide_allocation, it makes its own msdk bufferpool.
  - If downstream supports video meta, it just replace it with the msdk
bufferpool.
  - If not, it uses the msdk bufferpool as a side pool, which will be
decoded into.
    and will copy it to downstream's bufferpool.

2\ Decide if using video memory or system memory.
  - This is not completed in this patch.
  - It might be decided in update_src_caps.
  - But tested for both system memory and video memory cases.

https://bugzilla.gnome.org/show_bug.cgi?id=790752