Bug 492922 - Videos show with ~5fps at 200% CPU, while same video on VLC is absolutely smooth
Summary: Videos show with ~5fps at 200% CPU, while same video on VLC is absolutely smooth
Status: REPORTED
Alias: None
Product: digikam
Classification: Applications
Component: Preview-Video (show other bugs)
Version: 8.5.0
Platform: Appimage Linux
: NOR normal
Target Milestone: ---
Assignee: Digikam Developers
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-09-09 21:35 UTC by Jens
Modified: 2024-09-15 09:43 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


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Description Jens 2024-09-09 21:35:11 UTC
SUMMARY: see subject

STEPS TO REPRODUCE
1. start Digikam
2. start previewing any video file (I tried FullHD h.264 MP4 and h.265 MP4, generated on three different devices)
3. watch CPU load and fps

OBSERVED RESULT
video stutters (played from a local ext4 disk) and has a rough fps of 5..10, not more, 'digikam' uses 200% CPU.
Same video file played using VLC is absolutely smooth and uses barely 5% of one core.

EXPECTED RESULT
Video playback should be smooth and not stuttering.

SOFTWARE/OS VERSIONS: KDE Neon 22.04 with Digikam Qt6 appimage dated 20240908.
Comment 1 caulier.gilles 2024-09-10 05:30:57 UTC
Can you share a video sample to test. Please use a cloud storage link.
Comment 2 Maik Qualmann 2024-09-10 05:38:35 UTC
@Jens, are you using Wayland?

Maik
Comment 3 Jens 2024-09-10 14:40:31 UTC
Wayland, yes.
Comment 4 Jens 2024-09-10 18:40:29 UTC
I just noticed, the -Qt5 version does not have this problem. Only the Qt6 build.
Comment 5 Maik Qualmann 2024-09-13 11:14:45 UTC
Can you please post a log of the terminal if you play a video with the QT6 version of the Appimage?

--------------------------------------------------------------------
export QT_LOGGING_RULES="digikam*=true"

digikam
--------------------------------------------------------------------

Maik
Comment 6 Maik Qualmann 2024-09-15 09:43:16 UTC
Git commit 9a74e01d09819894241f10816ec8af14d8b479c1 by Maik Qualmann.
Committed on 15/09/2024 at 09:42.
Pushed by mqualmann into branch 'master'.

always assign a video backend to environment variable
And make the video backend platform
dependent selectable in the setup.
Related: bug 487031

M  +9    -5    core/app/main/main.cpp
M  +9    -5    core/showfoto/main/main.cpp
M  +12   -2    core/utilities/setup/misc/systemsettings.cpp
M  +6    -1    core/utilities/setup/misc/systemsettings.h
M  +42   -5    core/utilities/setup/misc/systemsettingswidget.cpp

https://invent.kde.org/graphics/digikam/-/commit/9a74e01d09819894241f10816ec8af14d8b479c1