Speed/Duration question

Hi. I have recorded footage in 50 fps to slow it down twice. My project fps settings is 25 fps. When I'm using speed/duration tool and change footage speed to 50% (50 to 25 fps) the final result is not smooth. But when change video frame rate in properties window to 25 fps it is very smooth.

I can't change composite shoot speed from 50fps to 25 with properties window, because HF crashes then (dump sent). Slowing CS down with speed/duration produces same not smooth result. I have to render each CS to 50 fps avi, then  import it again and change video frame rate to get smooth and slow animation.

My question is, why Speed/Duration tool works different than video framerate setting and is there any chance this function will work same as video framerate?


  • Are you sure you are using the Speed/Duration tool, and not the Speed effect? The Speed effect (in the Effects panel) uses frame blending, and gives different results (by design) than either changing the framerate of the clip or using the Speed/Duration tool, on the timeline of HitFilm 4 Pro.

  • I'm sure. I can do a test movie later, because now HF is rendering  one of the scene.. which took about 8 hours long ;), so I don't want to disturb "him".

  • OK. When you say it isn't smooth, can you clarify what you mean? If the playback is just stuttering, then its not being rendered in real-time, and using the RAM preview should sort it out. If there is a different sort of 'not smooth' happening, please give more details regarding what you are seeing.

  • I've rendered the movie to mp4 and after that playback is stuttering. I'll do more tests tomorrow. I hope the second experiment will also be positive ;).

  • I test it out again, and I know what is the reason. My main project is set to 25 fps. When using Speed/Duaration it calculates frames using these main comp settings, even if source media has 50fps it convert it first to 25 then change speed.

    When I increase main comp fps to 50, then speed set to 50% it looks ok. Also, when I change media fps to 25 it looks ok, but then I can't have two pieces of one media played with different speed.

    And a little test:



  • @Onixarts "Also, when I change media fps to 25 it looks ok, but then I can't have two pieces of one media played with different speed"

    You can import a media file more than once so you can mark one of them at a different framerate. You are allowed to rename media in the media panel so you can make it easy to identify the one(s) where you changed the playback frame rate. When you rename in the media panel it does not rename the file on disk. 

  •  I know, but it's a little bit harder to working with, especially when I want to cut it few times and stretch these pieces.

  • Aladdin4dAladdin4d Moderator

     You can also just right click on any media in the media panel and select Duplicate. 

    Having multiple copies of the same clip is really the only way to do what it sounds like you want to do be it duplicating the media, a comp or a layer with the clip.

  • Yes, but then You have to match each duplicated media to keep frames continuity. So increasing main comp fps is the best solution for now.

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