Bug 449700 - When previewing timeline, playback pauses briefly at each new clip
Summary: When previewing timeline, playback pauses briefly at each new clip
Status: CONFIRMED
Alias: None
Product: kdenlive
Classification: Applications
Component: Timeline & Editing (other bugs)
Version First Reported In: 21.12.2
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: Jean-Baptiste Mardelle
URL:
Keywords: triaged
Depends on:
Blocks:
 
Reported: 2022-02-06 14:34 UTC by DonnW
Modified: 2025-05-21 18:42 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:
fritzibaby: Brainstorm+


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Description DonnW 2022-02-06 14:34:28 UTC
SUMMARY
**
When previewing  timeline, playback pauses briefly at each new clip
***

As Play-head passes each clip on the timeline, playback on the project monitor briefly pauses. This also occurs during a dissolve/wipe transition. This does not happen with previous version before 21.12.0.  Occurs with both Appimage and Flatpak. Video clips used in project are 1080p/ 50 fps/ .mts 

STEPS TO REPRODUCE
1. Load a project
2. Play through timeline until clip changes
3. Also occurs when clips have been added to a new project

OBSERVED RESULT

Preview plays smoothly until next clip or transition in timeline is reached, play back pauses briefly ( <1s) . Playback sometimes continues to play back at a low frame rate

EXPECTED RESULT

Smoothly cut or transition to next clip and continue to play smoothly.

SOFTWARE/OS VERSIONS

Linux:  Kubuntu 21.10/KDE Plasma: 
(available in About System)
KDE Plasma Version:  5.22.5
KDE Frameworks Version: 5.86.0
Kernel version: 5.13.0-28-generic
Qt Version: 5.15.2

ADDITIONAL INFORMATION

Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-4790K CPU @ 4.00GHz
Memory: 23.4 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 750 Ti/PCIe/SSE2
Comment 1 DonnW 2022-05-14 18:42:15 UTC
Still the same problem in version 22.04
Comment 2 emohr 2022-05-16 18:25:59 UTC
I have exactly the same issue on Windows. If you change "Track Compositing" to None it doesn't happen (https://docs.kdenlive.org/de/cutting_and_assembling/editing.html?highlight=compositing#timeline-toolbar). With set to "None", clips with alpha channel, like title clips, on the track above show black instead of transparent while playback and rendering.