Don’t allocate internal memory via external allocator (+ don’t allocate via a WA)

[dvrogozh]

Initially filed and discussed here: Intel-Media-SDK/samples#13. Since this is not samples issue (at least not only), moved to track in Media SDK library repo.

As of now we need to:

1. Make sure that no mediasdk codecs allocate internal memory via external allocator. Suspected codec is HEVC encoder
2. Consider deletion of external memory allocation for bitstreams.

[lizhong1008]

FFmpeg hevc works! Thanks a lot for your support!
One question, how about the status of other codecs? For example, vp9 hw encoder (though hasn't implemented in ffmpeg, I will add it soon).

[artem-shaporenko]

VP9 still need to be updated.

[lizhong1008]

So, would you please create a new issue to check vp9 encoder since this one has been closed? @artem-shaporenko @dvrogozh

[dvrogozh]

Let's track vp9e in #762.