[FFmpeg-user] Change frame rate without dropping/adding frames

[Elliott Balsley]

Hello,
I want to take a video at 60fps and convert it to 24fps, without adding or dropping frames.  So the duration would be 2.5 times longer and the video would play in slow motion.  I realize the setpts filter can do this, but I’d like to avoid re-encoding.  This is possible in most NLE software, like Adobe Premiere or Apple Cinema Tools; is there a way to do it in ffmpeg?  When I try setpts with “vcodec copy” I get the error “Filtering and streamcopy cannot be used together”.