ffmpeg
Get info only (encoding, etc)
ffmpeg -i input.avi
Convert to x264
ffmpeg -i input.mp4 -c:v libx264 output.mp4
Working convert for video/audio for Plex: MKV, x264, AAC, 8-bit
ffmpeg -i Andrei.avi -c:v libx264 -pix_fmt yuv420p -c:a aac -strict -2 Andrei.mkv
Convert .ass subtitles to .srt
ffmpeg -i subs.ass subs.srt
Adjust subtitle timing
(6.5 second adjustment)
ffmpeg -itsoffset 6.5 -i .\Fellowship.of.the.ring.srt -c copy .\Fellowship.of.the.ring.FIXED.srt