@REM Convert mpg files to ac3 with 128k autio and video encoded with libx264 
@REM If you get unknown codec, get a build with the flag, e.g. https://www.gyan.dev/ffmpeg/builds/
forfiles /s /m *.mpg /c "cmd /c ffmpeg -i @file -codec:a aac -ar 44100 -b:a 128k -codec:v libx264 @fname.mp4"