Hi,
thank you for the patch; this fix looks promising, but I need to do a few more tests to make sure that it is working.
Please consider building the library libtegrav4l2.so for the previous version of l4t SDK - 32.2.3.
Unfortunately, the current version 32.6.1 of the SDK has serious issues with decoding interlaced live sources
( Possible multimedia api regression with decode interlace source - #12 by khizbulin ) and this prevents us from fully test and utilize your solution for decoder flush deadlock.