https://bugs.kde.org/show_bug.cgi?id=520555
Bug ID: 520555
Summary: Kdenlive proxy generation ignores rotation metadata,
causing mismatch with correct timeline rendering
(GoPro HEVC)
Classification: Applications
Product: kdenlive
Version First 26.04.1
Reported In:
Platform: KDE Linux
OS: Linux
Status: REPORTED
Severity: normal
Priority: NOR
Component: Rendering & Export
Assignee: [email protected]
Reporter: [email protected]
Target Milestone: ---
Version / Environment
OS: Fedora 44 KDE Plasma
Kdenlive: 26.04.1
FFmpeg: 8.x (system build)
MLT: system package (version available in Fedora repos)
Kdenlive install type: RPM (/usr/bin/kdenlive)
Summary
When importing GoPro HEVC clips that contain rotation metadata (displaymatrix),
Kdenlive timeline playback renders the video correctly, but generated proxy
clips ignore rotation metadata and appear incorrectly oriented.
This causes a mismatch between timeline preview and proxy preview.
Steps to reproduce
Import GoPro HEVC video into Kdenlive
Video properties:
Codec: HEVC (H.265)
Resolution: 5312x2988
Contains rotation metadata (displaymatrix: -180°)
Enable proxy clips
Generate proxies
Observe proxy preview orientation
Actual result
Timeline playback shows correct orientation
Proxy clips appear incorrectly rotated / orientation does not match timeline
Expected result
Proxy clips should match timeline rendering exactly, including rotation
metadata handling.
Additional technical notes
This issue only appears in proxy generation pipeline
Timeline playback (MLT) correctly applies rotation metadata
Proxy generation appears to ignore or inconsistently apply displaymatrix
rotation during frame processing
This suggests inconsistent handling of rotation metadata between:
MLT timeline rendering pipeline
Kdenlive proxy generation pipeline (FFmpeg-based encoding path)
Media details (example file)
Format: MP4 (GoPro)
Video: HEVC (hvc1)
Resolution: 5312x2988
Frame rate: 29.97 fps
Metadata: rotation (displaymatrix -180°)
Workaround
A workaround is to preprocess files by removing reliance on rotation metadata
(e.g. re-encoding with rotate=0 metadata or neutralizing orientation), which
makes proxy generation consistent.
However, this is not ideal as it requires external preprocessing outside
Kdenlive.
Notes
The issue appears to be related to how rotation metadata is handled differently
between timeline playback and proxy generation stages.
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