QMediaplayer 6 bad performance
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I meant to write "At first the QMediaplayer 6..."!
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Hi,
The multimedia module has seen a big rewrite. The current default backend is ffmpeg which should work pretty well.
Do you have references for the videos that triggers these issues ?
Are you using widgets or QtQuick ? -
Widgets. Works fine on Linux not Windows.
I noticed that some versions QtQuick worked, Widgets didn't.
None of the videos work well, some aren't even visible. -
Which exact version of Qt are you testing ?
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Currently the latest, but from 6 onwards it has never worked on Windows.
I tested on several computers. Currently the QMediaplayer library works on Linux (previously not or badly), but not on Windows. On Linux updates often caused problems.
Version 5 works perfectly on Windows and is able to play any video well and with minimal CPU usage! -
From the tests I'm doing on all types of videos and encodings, it appears that players based on Qt 5 play videos better, at least on Windows, with greater fluidity, safety in repositioning, without flickering, and with minimal use of the CPU, always less than 1%.
New technologies are not always the best!
Let's hope the design team of the library in question manages to achieve a miracle again.
It must be said that the ffplay player included in ffmpeg gives the same excellent results. So it's not ffmpeg that's the problem, I guess. -
Can you check wether you have the same issue with QtQuick ?
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The problem could be due to directx 12 and some drivers. Maybe a bug.
I saw that VLC also has a similar problem, but it is solved by changing the hardware encoding from automatic to directx 11.
It is likely and explains why 5, the integrated player of ffmpeg and other players work perfectly, with excellent performance with any video.
Is there a way to force the use of directx 11 in mediaplayer via code or something else?
How can you use the vlc library in a Qt project? -
N Nhan Nguyen moved this topic from General and Desktop on
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Yes, it's as you say. It's a bug.
I created a player using the VLC library and solved it with:if (player) {
libvlc_media_player_stop(player);player = NULL;
}source = QDir::toNativeSeparators(source);
libvlc_media_t *vlcMedia = libvlc_media_new_path(instance, source.toStdString().c_str());
libvlc_media_add_option(vlcMedia, ":avcodec-hw=d3d11va");
The Qt 5-based player is unbeatable on Windows!
Too bad! -
Sounds like something we should improve in Qt 6 then. Could you please submit a bugreport to https://bugreports.qt.io, along with the following info?
- The Qt version tested
- Details on your machine (Windows in this case)
- The media backend used (Windows-native vs FFmpeg)
- A reproducer (including a video sample that we can use for testing)
