Is there a lossless (or as close as possible) way to convert from 30 fps to 23.976?

[Serums]

I've got a video running at 30 fps and I'd ideally like to have it running at film speed. What would be the preferred way to do this? Does anyone have a preferred method/tool?

Thanks!

You can slow down the video by changing the frame rate in mkvmerge or tsmuxer. That will not change the video encoding at all.

Problem is most 30/29.97 video is interlaced and needs to be ivtc’d which is a process in of itself.

If it is progressive I would check for dupe frames just in case.

[Serums]

Thought as much. Wasn't the frame rate we were expecting, but we'll work with it. Thanks for the advice, PDB!