After rendering, the difference between 24 FPS and 60 FPS is not obvious

Hello, I was making a video comparing 24 FPS to 60 FPS, but when I render with ShotCut, I can’t see the difference. I watch the video with extreme slowness but it looks the same.

In my video, I rendered 3 animations with Source Filmmaker, an animation program. I rendered these 3 animations at both 60 FPS and 24 FPS, so this is a real 60 FPS animation. When I watch these source animations side by side, I can easily see the difference in the fluency of the videos even without slowing down the video. But for some reason, when you put two videos side by side and render with shotcut, the difference disappears completely.

The video is here:

I know this is about animation, but the voice actor has a hilarious voice too. :slight_smile:

Shotcut has a thing called Video Mode, which is basically the native resolution and frame rate of the timeline (project). All source files will be conformed to the Video Mode at export, regardless of their original frame rate or resolution.

In your case, I can step through the YouTube video one frame at a time (with the “,” and “.” keys) and see that frames are being duplicated on a 2-3 cadence… two duplicates, three duplicates, repeat. This tells me the Video Mode in Shotcut was 24fps (or 23.98fps) but then the Export > Advanced screen was overridden to 60fps. This will not work.

As an example, the 60fps source animation will be conformed to the 24fps timeline, which means 36 frames removed every second to drop it down to the Video Mode specification. When the override of 60fps is specified on the Export > Advanced panel, the 24fps timeline has its frames duplicated back up to 60fps, which is why there is no visual difference between a 24fps source and a 60-that-was-dropped-to-24fps source. This is also why both animations show a 2-3 stutter cadence.

The solution is to change the Video Mode to 60fps, then do not override anything in Export > Advanced.

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Thank you. It’s worked!

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As for how this problem happened in the first place… The default Video Mode when starting a new Shotcut project is Automatic. This means the Video Mode will set itself to the same frame rate and resolution as the first video added to the project. If the 24fps video was added first, then you now have a 24fps project. Adding a 60fps video to the project will conform the 60fps video down to the project’s 24fps. The situation would be reversed if the 60fps video was added first.

This is why users with a working knowledge of video editing are advised to manually set the Video Mode at the start of a new project. It removes potential future problems such as this.

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