Ffmpeg mmal and the pi

[Tdi-Me]

I have a rpi3 with the mpeg2 license. I also have ffmpeg compiled with mmal for mpeg2 hardware acceleration decoding. Can anyone tell me the ffmpeg command to say use hardware acceleration decoding a mpeg2 and then encode it to MP4 using hardware acceleration? Please

[emma24xia]

Use the following configure command (Use correct CUDA library path in config command below)
./configure --enable-cuda --enable-cuvid --enable-nvenc --enable-nonfree --enable-libnpp
--extra-cflags=-I/usr/local/cuda/include --extra-ldflags=-L/usr/local/cuda/lib64

To start with FFmpeg, try the below sample command line for video transcoding
ffmpeg -i input.mpg2 output.mp4