Export frame-rate issues caused by imported source files


Computer Specs: Windows 10, Intel i5-4460 @ 3.20Ghz, 8GB RAM, NVIDEA GTX 750 Ti GPU.

Longtime HitFilm express user (currently on HitFilm Express 2017). I run a film analysis/review YouTube channel and have made 16 videos or so using HitFilm. As such, my source material for editing are films

Most files I work with are .mkv files. Incompatible with HitFilm, but I've been using Handbrake to turn them into .mp4 files with an H.264 codec. Have not had any issues in this department until now. 

With the latest project I've been working on, playback and stuttering/frame-rate issues has been frequent in HitFilm, but this was nothing to be alarmed about as this is usually the case. Once exported, the frame-rate issues disappear. I proxied the source file, it ran better, so I kept working. 

Just to make sure that everything was working properly, I exported a 60s clip of my project, and found that the exported clip had serious frame-rate issues. See here: 

At first I thought the problem was an incorrect matching of frame-rates; the source file is 23.976fps, but the project and composite shot you see above is 30fps. So I ran some tests with the source material and found that, no matter what FPS the project file is, or what the export preset is, the exported frame-rate issues persisted. 

I experimented with different source files and found that "native" .mp4 files (ones I did not have to convert myself) ran and exported out of HitFilm with no frame-rate issues whatsoever. However, any .mkv file I ran through Handbrake had some amount of frame-rate problems once exported out of HitFilm, but nothing remotely as awful as what I saw in the clip above. 

I looked into whether the .mp4 container and H.264 codec was somehow the problem. I searched the forums and found this thread:

I followed the instructions step-by-step, and using an .mp4 file I created a DNxHD AVI file. Tried to import to HitFilm, and I get the error message "The media could not be imported."

As another fun little wrinkle, some .mp4 files that I have simply crash HitFilm when I try to import them.

As of now I have worked with 5 different  versions (4 .mkv files and one .mp4) of the same movie, have tried to convert all of them into a usable format that will not cause framerate problems, and nothing has worked. I have 10 versions of the same movie taking up a collective 170 GB of memory and none of it is usable.

I've sunk around 40 hours into this project and I'm not walking away from it. Someone, anyone, please help me.


  • Handbrake can't deal with 23.976fps footage. It produces variable rate output, which Hitfilm then mistakenly interprets as 24fps. Can't remember what's a better solution. I use Shotcut, but @NormanPCN will have better information for you.

  • UPDATE: I fixed the problem by throwing money at it.

    If anyone else runs into similar issues, I fixed it by doing as follows:

    1. Buy the source file off of iTunes

    2. Buy TunesKit ($60) https://www.tuneskit.com/ ;

        This will give you a lossless .mp4 stripped of the DRM.

    3. Convert.

    4. ??? Profit

    I won't be using Handbrake in the future but will give Shotcut a look. 

  • For conversion/transcoding, another option is MPEG Streamclip.  I can't speak to how well it deals with precise frame rates like 23.976fps, but it might be worth a look.

  •  I used Streamclip for creating the AVI file but HitFilm didn't recognize it for whatever reason.

  • DNxHD must be in a MOV container file and not AVI. Avid only installs their codecs for Quicktime MOV and no other subsystem. Such as Video for Windows (AVI). Installing the Avid codecs is the only way to get DNx codecs for use in Hitfilm.

    If you are transcoding to an intermediate format, with Hitfilm 2017+ you are best off transcoding to Cineform for best performance. Support for Cineform in AVI is native in Express 2017 and no codec installs are necessary.

    I'll reference the main transcode info thread which references numerous other sub-threads with detailed info on some specific codecs (like Cineform).


    I'll directly reference my thread on AVC transcoding as it has some information on the Handbrake bug with 23.976 and 59.94 frame rates and possible workarounds.


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