Bug 511851

Summary:	Unchecking "Proxy Clip" breaks clip durations in timeline when they have slow Playback Speed
Product:	[Applications] kdenlive	Reporter:	Die4Ever <die4ever2005>
Component:	Timeline & Editing	Assignee:	Jean-Baptiste Mardelle <jb>
Status:	RESOLVED FIXED
Severity:	normal
Priority:	NOR
Version First Reported In:	25.08.1
Target Milestone:	---
Platform:	Kubuntu
OS:	Linux
Latest Commit:	https://invent.kde.org/multimedia/kdenlive/-/commit/e3375afd441c1c981b922c84f45c60da43d97d2f	Version Fixed/Implemented In:	25.12.0
Sentry Crash Report:
Attachments:	observed result screenshot

Description Die4Ever 2025-11-09 07:08:33 UTC

Created attachment 186633 [details]
observed result screenshot

SUMMARY
Unchecking the "Proxy Clip" box undoes desired duration of low Playback Speed clips in the timeline.

STEPS TO REPRODUCE
1. Download project: https://drive.google.com/drive/folders/1ePmXX3tAwtdBzY_5_Ne5uhk8IL9PgasG?usp=sharing
2. Open "test before.kdenlive"
3. Right click the mp4 file in the Project Bin
4. Uncheck "Proxy Clip"

OBSERVED RESULT
The clips in the timeline are normal duration with slow speed instead of being longer duration due to their slower speed. Screenshot: https://drive.google.com/file/d/19hFBjMdIl44YzGwvI6zJKbdUEM7wQTRd/view?usp=drive_link

EXPECTED RESULT
The clips should still be at slow speed.

SOFTWARE/OS VERSIONS
Operating System: Kubuntu 25.10
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.2
Kernel Version: 6.17.0-6-generic (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 2600 Six-Core Processor
Memory: 16 GiB of RAM (15.0 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 2080

Comment 1 Jean-Baptiste Mardelle 2025-11-15 15:35:05 UTC

Thanks for your detailed report.
I can confirm that enabling or disabling proxy on a clip resets its duration when it has a speed change, working on a fix.

Comment 2 Jean-Baptiste Mardelle 2025-11-15 15:58:53 UTC

Git commit e3375afd441c1c981b922c84f45c60da43d97d2f by Jean-Baptiste Mardelle.
Committed on 15/11/2025 at 15:58.
Pushed by mardelle into branch 'release/25.12'.

Fix proxying changing timeline duration of clips with speed change
FIXED-IN: 25.12.0

M  +1    -1    src/timeline2/model/timelinemodel.cpp

https://invent.kde.org/multimedia/kdenlive/-/commit/e3375afd441c1c981b922c84f45c60da43d97d2f