Bug 459009

Summary:	AV1 video preview does not work in Dolphin
Product:	[Applications] dolphin	Reporter:	80p3fy75dc
Component:	general	Assignee:	Dolphin Bug Assignee <dolphin-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	aristsakas, asturm, dolphin-bugs-null, kdedev, luigi.toscano
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Gentoo Packages
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	AV1 video sample

Description 80p3fy75dc 2022-09-11 18:42:18 UTC

Created attachment 151992 [details]
AV1 video sample

STEPS TO REPRODUCE
1. Download the attached sample AV1 video (or from source: https://dl8.webmfiles.org/BigBuckBunny-AV1.webm)
2. Run dolphin from a terminal
3. Select "BigBuckBunny-AV1.webm" and click on the play icon in the preview panel to start the preview

OBSERVED RESULT

The preview does not work (both video and audio) and the following is printed in the terminal:

QPainter::begin: Paint device returned engine == 0, type: 1
QPainter::begin: Paint device returned engine == 0, type: 1
QPainter::begin: Paint device returned engine == 0, type: 1
(dolphin:20414): GStreamer-Video-CRITICAL **: gst_video_center_rect: assertion 'src->h != 0' failed


EXPECTED RESULT

The preview works (both video and audio)


SOFTWARE/OS VERSIONS
- Distro: Gentoo
- KDE Plasma Version:  5.25.5
- KDE Frameworks Version: 5.97.0
- Qt Version: 5.15.5
- Dolphin version: 22.08.1
- X11

ADDITIONAL INFORMATION

I don't have the issue with HEVC or x264 video files. I tried with multiple AV1 videos with different extensions (avi,mkv,mp4): same issue

Installed packages and versions:

- kde-apps/ffmpegthumbs:22.08.1
- kde-apps/kdesdk-thumbnailers:22.08.1
- kde-apps/thumbnailers:22.08.1
- kde-frameworks/kimageformats:5.97.0
- dev-qt/qtimageformats:5.15.5-r2
- media-libs/phonon-gstreamer:4.10.0

Relevant USE flags:

kde-frameworks/kfilemetadata epub ffmpeg

Comment 1 80p3fy75dc 2022-09-11 20:22:33 UTC

Installing media-plugins/gst-plugins-aom partially solved the issue. Now, previews work fine with mp4 and mkv files. However, with avi files, only the audio works, the image is stuck.

Comment 2 Christoph Cullmann 2024-09-22 19:04:25 UTC

kdemultimedia is no longer maintained.

If you have issues like you reported with current versions of our applications, please report the issue at the bugtracker of the application.

Comment 3 Luigi Toscano 2024-09-22 19:48:19 UTC

This is about ffmpegthumbs which is still maintained.

Comment 4 TraceyC 2025-06-02 15:06:50 UTC

Moving to the correct category.

Comment 5 TraceyC 2025-06-02 15:39:53 UTC

I re-tested this with Dolphin built from git-master (25.07.70) and it appears the bug has been fixed
I downloaded the attached webm file and opened the folder in Dolphin.
When I click the Play button in the preview pane, the preview starts playing.

If you can reproduce this bug with Dolphin 25.07.70 or later, please re-open this bug. Thanks.

Comment 6 Luigi Toscano 2025-06-02 22:16:56 UTC

Thanks for checking - but than dolphin this bug was about ffmpegthumbs and if it seems we don't have a bugzilla category for ffmpegthumbs, and we should.

Comment 7 Antonio Rojas 2025-06-03 06:39:48 UTC

(In reply to Luigi Toscano from comment #6)
> Thanks for checking - but than dolphin this bug was about ffmpegthumbs and
> if it seems we don't have a bugzilla category for ffmpegthumbs, and we
> should.

There is - under 'Frameworks and Libraries'

Comment 8 Antonio Rojas 2025-06-03 09:33:35 UTC

Note that this is not related to ffmpegthumbs though (which handles the thumbnails in the dolphin main view and in tooltips). This is about the video preview in the side panel, which is managed by dolphin itself. So dolphin was indeed the correct category.