Is there a (Linux or Windows) command line tool that is able to create a slow-motion version of a video file?
For a fun project, I want o record a short video (max 1 minute) from a compact camera (h624, 1020p @ 30 fps or 720p @ 60 fps), send it to a computer via a Eye-FI wlan card and show the recording in slow motion. All with the slowest waiting time possible, fully automated and several times with different recordings.
The simple solution that comes to my mind would be to change the metadata by lowering the indicated frame rate. Even better would be some interpolation or even warping algorithm that generates a higher quality.
The playback speed should be around 20% to 50%, depending on the resulting quality that's still looking somewhat good. Playback could be done with Macromedia Flash, mplayer, VLC or something.
I don't know any tools that modify video files in an automated way (except for writing my own program to change the video file metadata).