Bug 491601 - Transcoding from VFR to CFR does Nothing
Summary: Transcoding from VFR to CFR does Nothing
Status: RESOLVED FIXED
Alias: None
Product: kdenlive
Classification: Applications
Component: Rendering & Export (show other bugs)
Version: 24.05.1
Platform: Microsoft Windows Microsoft Windows
: NOR minor
Target Milestone: ---
Assignee: Jean-Baptiste Mardelle
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-08-12 00:00 UTC by ammarzawar123
Modified: 2024-08-13 02:54 UTC (History)
0 users

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Latest Commit:
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Description ammarzawar123 2024-08-12 00:00:28 UTC
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SUMMARY
When it tries to transcode a video from VFR to CFR via 'Lossy x264 | frame only', it doesn't do anything.

STEPS TO REPRODUCE
1.  Import any framerate with a variable framerate.
2.  Kdenlive will say that this you need to transcode it into a constant framerate video. Let it transcode with 'Lossy x264 | frame only'.
3.  Now let it transcode.

OBSERVED RESULT
The video makes a copy of itself, with the original name and the new framerate appended to it. Kdenlive automatically replaces the old one with the copy, but the framerate is completely unchanged, so it's still VFR. Kdenlive recognizes this, and tells you to transcode it to CFR, causing an unending cycle of failed transcoding.

EXPECTED RESULT
The video makes a copy of itself, with the original name and the new framerate appended to it. Kdenlive automatically replaces the old one with the copy, and since it's now CFR there are no more issues.

SOFTWARE/OS VERSIONS
Windows: Windows 11 Home, Build 22631
KDE Frameworks Version: Version 6.3.0
Qt Version: Version 6.7.1 (built against 6.7.1)

ADDITIONAL INFORMATION
CPU: AMD Ryzen 5 3600
GPU: Nvidia RTX 3060
RAM: 12 GB
They also get bigger for some reason.
Comment 1 ammarzawar123 2024-08-12 01:34:28 UTC
Oh, and if this helps, I have a .bat script to convert them myself. Here's the ffmpeg command if you're interested.

ffmpeg -y -fflags +igndts -i input.video -filter:v fps=%new_fps% -fps_mode:v cfr -copytb 0 -c:v libx265 -crf 17 -tag:v hvc1 output.video
Does re-encode it, but it works flawlessly on anything I throw at it.
Comment 2 Jean-Baptiste Mardelle 2024-08-12 08:13:26 UTC
Thanks for your report. This is in fact fixed for the 24.08 version. Would be great if you can test the daily build to confirm:
https://cdn.kde.org/ci-builds/multimedia/kdenlive/release-24.08/windows/
Comment 3 ammarzawar123 2024-08-13 02:54:34 UTC
Tested with the build and 'Lossy x264 | frame only', and it works perfectly!
Thanks!