I have been messing around with ffmpeg working on basic mkv to mp4 conversions the last couple of days on my Mac and Windows computers. Mac was easier buy my windows desktop has a much faster OS so I wanted to do some conversions on it tonight. Got ffmpeg installed and working.

After having some issues with the command prompt not finding the directory, I solved that with the following basic code to convert an mkv file to an mp4 for me:

ffmpeg -i "C:UsersComputervideosdecade.mkv" "C:UsersComputerVideosRJ videosCompletedecade.mp4"

I moved on to wanting to scale up an mkv to 1080p and use a yadif filter. I couldn’t find an adequate way to do this so I used a portion of the command that worked on my Mac last night, and stuffed it into the command for windows and I got an error code “at least one output file must be specified” after using the following command:

ffmpeg -i "C:UsersComputervideosdecade.mkv" -vf "yadif=1,scale=1440x1080:flags=lanczos,setsar=1" -c:v libx264 -crf 21
-c:a aac -b:a 128k -ar 48k "C:UsersComputerVideosRJ videosCompletedecade.mp4"

What am I doing wrong?