A couple other things, you generally want to do pixel format conversion before the codec, is specified. You should be able to get satisfactory results with ffmpeg -i input.mpv -pix_fmt yuv420p -c:v libx264 -preset medium -crf 24 -c:a aac output.mp4 Play with preset a bit since that is where your Quality/Compression : Speed ratio comes in, CRF is the quality it handles. So you set CRF for a ballpark quality you want, then change the preset, slower = higher compression, faster = lower compression.