NvDec not working with FFmpeg 4.3 from C++ API

Please try the default package and see if it works:
Jetson Nano FAQ

Q: Is hardware acceleration enabled in ffmpeg

Some related posts for reference:
Jetson TX2 and FFmpeg - Can't initialize nvrm channel - #5 by DaneLLL
Hardware accelerated video playback with L4T ffmpeg - #7 by DaneLLL

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