Using 240fps HEVC file as 24fps slow motion in Hitfilm Express

Hi,

I'm using Hitfilm Express 8 and I would like to import HEVC encoded 240fps footage from the GoPro Hero 6 and use it as 24fps slow motion. If I understand correctly, Hitfilm does not support neither HEVC or 240fps so I'm trying to find a way to convert the file to 24fps in some suitable format before importing into Hitfilm. Just to be clear, I only want to change the fps from 240fps to 24fps. I want to keep all the frames and thus making the clip 10 times longer.

I found this page: https://gopro.com/help/articles/how_to/how-to-convert-gopro-hevc-videos-to-h-264-using-handbrake

but Hitfilm does not import the output file from Handbrake correctly. It is imported as 60fps in Hitfilm but I can see in Windows File Explorer and for example VLC Media Player that it truly is 240 fps. Also, the Handbrake output file is H264 which is not very good for editing.

Any help would be appreciated

Cheers

Comments

  • You can get reasonable editable AVC/H.264 output using some fast decode AVC settings.

    https://fxhome.com/forum/discussion/42415/transcoding-to-fast-decode-avc-for-timeline-edit-performance

    Handbrake, AFAIK, does not have features to transcode and remark the framerate to a lower setting, thus preserving all source frames. I believe it always resamples. Using something like VirtualDub you should be able to do that. Also with VirtualDub you can transcode to Cineform which should give better edit performance if that is a problem.

    https://fxhome.com/forum/discussion/42015/how-to-use-virtualdub-filtermod-to-fix-vfr-issues-and-convert-to-cineform

    To use Handbrake you would need to preserve the 240 fps which should not be a problem but Handbrake does have some issues with generating variable framerate files for some output framerates. I do not know if 240 is one of those problematic rates. Technically your 240 is actually 239.76 (29.97 * 8). When you bring that into Hitfilm you just change the framerate, via the media panel, to 23.976 or 24, whatever you need is. Hitfilm will not resample and just play the frames at your selected rate.

    You can use ffmpeg to transcode to fast decode AVC, or Prores, and remark the output framerate to whatever you want in one step. I don't have a script setup to do that but I could probably come up with one.

  • Many thanks Norman! Will explore these suggestion later this week.

  • It worked great. I imported the Cineform encoded .avi ouput file from VirtualDub into Hitfilm and then changed the frame rate in Hitfilm from 240 fps to 24 fps resulting in some awesome looking slow-motion.

    Thanks!

     

  • edited July 2018

    Not that it matters and just in case anyone stumbles across this thread but you can have VirtualDub set the slow mo framerate in the transcode. In the video menu, frame rate menu item, just change the source frame rate field to the value you want. The result file from VirtualDub will be that rates and all source frames are retained.

    Astute readers will notice this is exactly what you are doing by setting the frame rate in the Hitfilm media panel. You are telling the application to interpret the framerate as what you specify an not what is listed in the file description metadata.

    With VirtualDub you have more flexibility in choosing the source frame rate. Which if looking for a specific slowmo speed may be useful. Frame rate retiming in Hitfilm really sucks.

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