Created attachment 203660 [details]
Since last qt-webengine port update I cannot see html5 videos with correct color.
https://www.quirksmode.org/html5/tests/video.html , video is played in blue color.
www.youtube.com videos are played in green/black colors.
I tested with falkon and otter-browser with webkit and webengine backends, only webkit backend works normally.
I'm using freebsd 12.0 with latest ports.
I have take some screenshots.
Created attachment 203661 [details]
otter with webengine
Created attachment 203662 [details]
otter with webkit
Created attachment 203663 [details]
*** Bug 237330 has been marked as a duplicate of this bug. ***
I think the problem is that we need to get back WebRTC.
See https://wiki.qt.io/QtWebEngine/VideoAcceleration .
qutebrowser has the same issue. For those who are looking for a quick fix: forcing software rendering helps, e.g, "c.qt.force_software_rendering='chromium'".
I'm using nvidia-driver on FreeBSD 12.0-RELEASE-p2. The only browser I have that uses qt-webengine (according to pkg info -d) is konqueror. The video at quirksmode looks fine to me.
Just including another result in the hope that it can help narrow things down.
I think this is not a real bug, but a misconfiguration with hardware acceleration, as comment #6 and comment #7 also suggest.
If you have a recent enough hardware, you should try to get hardware acceleration working properly. This page, although for arch linux, can help: https://wiki.archlinux.org/index.php/Hardware_video_acceleration
If, on the contrary, you have an old graphic card, such as myself, you can disable hardware acceleration by starting your browser with --disable-gpu. I can confirm that this fixes the problem with falkon 3.1.0 and qt5-webengine 5.12.2_3 on FreeBSD 12.0-RELEASE r350836 amd64.
(In reply to Lorenzo Salvadore from comment #8)
My hardware is from 2010.
I've tested youtube videos with very good framerate and quality with "--disable-gpu" option.
This option works.
I was thinking if this option should be included in pkg-message in all browsers that use webengine as backend, I was waiting for this information for months.
I've just tested Falkon, I will try to test other browsers with the same issue.