ProRes 422 LT and HQ outputs have the wrong framerate

When exporting to ProRes 422 LT specifically, I found that the output framerate was wildly inconsistent and did not follow the project settings.

Originally, I had used H265 Main for my outputs, but after noticing the compression banding that was reported (“Too low compression / banding”), I switched to ProRes 422 LT which did fix the problem.

Unfortunately, only after importing all my exports into Davinci Resolve did I notice that the total length had shrunk by two minutes, meaning that my audio no longer synced up. This is because the framerate of each clip had been shifted from my input of 23.97 to some random framerate.

An example of the output framerates from a selection of files is also given. This is the same within Windows Explorer, VLC Codec Information, and Davinci Resolve. Davinci Resolve attempted to convert the fluctuating framerates to the original 23.97, which is why two minutes of the original video were missing.


My original settings are shown below

This can happen if your source video is VFR not CFR.
I see you have used windows properties to check file.
Also there is no audio I see on your output settings, so I dont know how it can be out of sync in Resolve…
Use mediainfo.

Interestingly, MediaInfo reports the two files as having the same framerate, even though the original files report in Windows Explorer as 23.98 and the exports are different. Perhaps Windows Explorer and VLC don’t properly know how to read ProRes frame rates. The input source is CFR on all the files. Also, the reason I didn’t have any audio is because I extracted it beforehand, upscaled the video, and then inserted it back in.



However, when I import both sets of clips into Davinci Resolve, the difference in length is clear. While the original sequence has a total length of 02:07:51:21, the upscaled clips have a total length of 02:06:45:12, meaning over a minute of video has somehow disappeared. Please note that I individually upscaled 1720 clips to make sure Topaz Video AI didn’t mess with scene cuts. As you can see from the image below, the lengths of each upscaled clip (on the top) are vastly different to the original (on the bottom) and make the final result unusable for audio syncing.

Using MediaInfo, I measured the reported length of each upscaled file in a different format and here are the results:

original: 2s 794ms
h264_high: 2s 794ms
h265_main: 2s 794ms
h265_main10: 2s 794ms
prores_lt: 2s 753ms
prores_hq: 2s 753ms

As you can see, ProRes obviously effects the output length.

Thanks for this information Nathan,

Our team is currently looking into a possible fix for this issue as it seems to be specific to certain ProRes outputs. I’ll let you know as soon as I have more information.

For more information, I was able to fix the problem by importing all the files into Handbrake, setting the framerate to a constant 23.98 fps, and setting the output quality to 100k mb/s (to prevent compression artifacts and banding). This was done using the H.265 2160p 4K preset and was outputted to MKV. Through this analysis, it is quite likely that the ProRes outputs have a problem with the framerate.

Were the original inputs recorded in a variable frame rate? If possible, could you upload one of them here:

You can securely submit your file(s) to our Dropbox using the link below. Please be sure to send me a note to let me know you sent something.

Submit to Dropbox

I sent you my format test files outputted in the 5 formats I mentioned above ( (the ProRes files are quite large). Also, I sent you the original file standalone (Untitled00007660.mp4). As far as I know, the original file is CFR, but you can check that for yourself. Please note that the original file has been denoised using Artemis in Video AI previously, but it was exported using H264 High which does not have the framerate problem. (Ignore Untitled00007660_original.mp4, I believe that is just the original file Untitled00007660.mp4)

Actually, scratch that, Untitled00007660_original.mp4 is the base file that has been unchanged (Untitled00007660.mp4 is the denoised second version). It was exported from Davinci Resolve Studio 18 using default settings, constant framerate, and variable bitrate.

To summarize, here are the steps as described:

  1. I split the original H264 video into scenes using Davinci Resolve, which I also exported as H264 (Untitled00007660_original.mp4).
  2. I denoised the export using Artemis and exported that to H264 (Untitled00007660.mp4)
  3. I upscaled the denoised export to ProRes 4k using Proteus (

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