SUMMARY Versions 24.5.1 and 24.5.2 of kdenlive on Win 64 incorrectly identify imported clips as having variable frame rate. STEPS TO REPRODUCE 1. Open a new project using kdenlive > 24.5.0 2. Import a stitched GoPro Fusion clip (which has 5504x2752 pixels @ 23.976 frame rate) OBSERVED RESULT 3. Warning dialogue about clip having variable frame rate, and therefore unsuitable for editing/use. Convert clip yes/no. EXPECTED RESULT Successful import of clip SOFTWARE/OS VERSIONS Windows: 11, build 23H2 22631.3958 ADDITIONAL INFORMATION Using GoPro Fusion Studio 1.4 to stitch raw clips for import into kdenlive. I can supply sample clip for diagnostics if required.
Could you provide a short video sample so that we can test this further ?
(In reply to Jean-Baptiste Mardelle from comment #1) > Could you provide a short video sample so that we can test this further ? 1sec video is c. 130Mb, so provided via Dropbox Link. I have reconfirmed that 24.05.0 is OK, but 24.5.1 and 24.05.2 give an error. https://www.dropbox.com/scl/fi/5p4wnt4j875foeu6cgfkv/TEST.mov?rlkey=cea13t1ac4wp39uvguhsle42a&st=731or6qx&dl=0
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I have confirmed this is also a problem with 24.08.0.
...and 24.08.1
Well MediaInfo also detects your video file as Variable Frame Rate, so I will close this bug. ----------------------------------------------------------------------------- Frame rate mode : Variable Frame rate : 23.976 (23976/1000) FPS Minimum frame rate : 23.970 FPS Maximum frame rate : 24.212 FPS
That doesn't alter the fact that these files are NOT variable frame rate, whether MediaInfo says so or not. I have tested with version 24.12.1 of kdenlive and it flags a warning that the clips are variable frame rate but seems to let me continue to use them, so I guess that will have to do for now. Your response does not explain how versions of kdenlive prior to 24.05.1 were quite happy to process these files but subsequent versions are not. I do appreciate that this difference may be caused by a change to a software component over which you do not have change control. However, it is a significant inconvenience to me as a long time kdenlive user.
Detection of VFR clips happens in MLT. Your clips doesn't pass a check comparing FFmpeg's average and real frame rates on the video stream : av_cmp_q(stream->avg_frame_rate, stream->r_frame_rate); https://github.com/mltframework/mlt/blob/master/src/modules/avformat/producer_avformat.c#L1398 If you think this is incorrect, it means that there is a problem within this check or in FFmpeg. However there are several reports of GoPro producing VFR clips, and you can see Dan's answer (the MLT maintainer)on this topic: https://forum.shotcut.org/t/constant-frame-rate-video-incorrectly-determined-to-be-variable-frame-rate-in-20-11-29/25112/3
Thanks for that additional info. I didn't realise it was an issue reported with other GoPro products or that it was potentially an issue with MLT not reporting that it had determined that the file had a variable frame rate. As you may know, GoPro fusion footage has to be "stitched" (using "GoPro Fusion Studio") to create a single .mov (or .mp4) file for each clip prior to futher editing. Opening the "raw" front and back camera files, MediaInfo reports a constant frame rate of 23.976 but, after stitching, (I agree that) the reported frame rate *mode* is "variable" (despite the stitching process being spatial not temporal). Possibly a bug in the GoPro code or its subcomponents (which hasn't been changed since 2018). My issue may well be that Fusion Studio is incorrectly flagging the output as VFR, a fact which has hitherto been ignored (or at least not reported by) MLT. As long as I can continue to use kdenlive to edit my footage (albeit with a warning about clips being flagged with variable frame rates), I'll be happy. I have certainly never noticed any judder on the output from kdenlive with frames being dropped, repeated or interpolated to give me a constant 23.976 output. I'll maybe stick with 24.05.0 for as long as I can. I definitely DON'T want my clips to be temporally converted on input. Thanks again.