Compositing Files With Different FPS?

cluelessnube Posts: 522 Enthusiast

Howdy all, hope your projects are going well. A question for ya...

What's the best way to composite two files with different FPS? As example, say you have a background video clip at 30fps, and you want to layer another clip at 25fps on top of it.

How do you expert pro advanced super nerd people go about this?



  • Stargazer54
    Stargazer54 Posts: 3,743 Ambassador

    @cluelessnube Personally I'm just kamakazee and will drag them both to the timeline. When you render, the frame rate will be adjusted to fit your frame rate from Project Settings.

    If you want to be more precise you would need to transcode to a frame rate that matches the other file and re-import that.

  • cluelessnube
    cluelessnube Posts: 522 Enthusiast

    Hi, thanks for your response, much appreciated.

    As best I can tell so far, the kamakazee method seems to work when the fps of both files are close. The greater the distance between the fps the more distortion, again, as best I can tell.

    Can you elaborate on what you mean by "transcode"? Process one of the files so it matches the fps of the other file? If yes, how do you go about that?

  • Stargazer54
    Stargazer54 Posts: 3,743 Ambassador

    Yes, match the fps of one of the files to the other. You might be able to do that with Handbrake. Tutorial on that here.

    Also you could try doing the conversion with HF. Read in the file to convert and set project settings to the desired fps then export and re-import into your main project.

  • Triem23
    Triem23 Posts: 20,519 Ambassador

    To build on what @Stargazer54 writes.

    Hitfilm "conforms" media to the fps clock when adding clips to the Timeline - so, if you add a 25fps clip to a 30fps Timeline Hitfilm tries to parse frames at that point. Or vice versa. Thing is, Hitfilm doesn't do a lot of frame blending/optical flow interpolation, so this can cause "stutters" and it puts the processing load on Hitfilm.

    A transcode will "burn in" the new frame rate and take the load off Hitfilm. A dedicated transcoder might also do better parsing/blending/interpolating frames.

    I'll kamikaze at times, but I think transcoding is the better option. Lynn (Stargazer) already gave Handbrake links.

    "Transcode" btw just means convert from one format to another. This applies to video data when converting (example) WMV to MP4 or converting a 25 fps file to 30 fps. Otherwise, transcode is a generic term. Translating a book from English to German is also a "transcode." Same content, new format.

  • cluelessnube
    cluelessnube Posts: 522 Enthusiast

    Thanks again Triem,

    I do have Handbrake. I'll try converting one file with Handbrake so it matches the FPS of the other file. Seems simple enough. Appreciate it!