ffmpegConvert video from H.265 to H.264 codec

ffmpeg -i in.mp4 -c:v libx264 -crf 18 -vf format=yuv420p -c:a copy out.mkvctrl + cyoutubegithub

`ffmpeg` name of the package to install	`-i in.mp4` input video file
`-c:v libx264` use H.264 video codec	`-crf 18` preferred quality level (`bitrate`), where `0` is lossless and `51` is worst
`-vf format=yuv420p` use `yuv420p` pixel format	`-c:a copy` copy audio without converting
`out.mkv` resulting video file