[mythtv] Mediacodec problem with fire stick 4K

[Peter Bennett]

Hi Aman

When running with mediacodec on the fire stick 4K, there is a problem 
with MPEG2. Perhaps the 4K does not support MPEG2 or the interlacing is 
causing a problem. What appears to happen is that we get the situation 
where we have done avcodec_send_packet until it returns AVERROR(EAGAIN). 
The avcodec_receive_frame also returns AVERROR(EAGAIN) and this 
continues forever, we never get a frame out of it. With h264 it works 
fine. If there is no MPEG2 support, maybe we should get an error return 
or it should revert to software decoding. Is there anything ffmpeg can 
do to avoid this, or do I have something wrong in my code?

I have set ffmpeg debug logging and captured the log. That is here -> 
https://pastebin.com/ZF9JiMTX
The code where we process packets is here -> 
https://github.com/MythTV/mythtv/blob/a1349d7f535dfcc5993a1f515e4ee2cb257e3aa6/mythtv/libs/libmythtv/avformatdecoder.cpp#L3686

Peter