Video export issues

Have been trying some video clip exports and two problems has troubled me.

For some reason selecting mp4 format results in very choppy playback for me. Not entirely sure it is the exported file or the windows kodek having trouble.
Exporting in mp2 format seems to make the video much smoother. Had to download an extra codek for it to play in W10.

Secondly the resulting video file is gargantuous, how come a 15 second clip is close to a gigabyte in size ?
Before the streaming services took off i remember 40 minute tv series episodes in decent resolution around the same filesize, is the video compression in pix4d really that bad?

A post was merged into an existing topic: Processing from a video