[FFmpeg-devel] hevc: fixes for hwaccel when running frame threaded

[Rainer Hochecker]

The first patch avoids unnecessary calls to get_format. We open a new
hw decoder on every call to get_format. hevc seems to do something
different than h264. deleting any provious allocated hw decoders
at the application level results in heap corruption. There may be some other
issue left but the multiple and unnecessary calls to get_format already
bothered us with h264 which should be fixed too.

The second patch avoids a flicker when running dxva frame threaded