Customize QVideoWidget and QMediaPlayer Metadata problems

TheEnigmist

I'm able to load and show a video at runtime, but I'm having problem doing some tasks:

I want to customize background of my QVideoWidget to a transparent background or at least a color (to understand how it works) but every change I made has no effect (is always black). I tried this:

QVideoWidget* videoWidget = new QVideoWidget(parent);
videoWidget->setStyleSheet("background-color: rgba(255, 255, 0, 50);"); // <- NO EFFECT even with Qt::WA_StyledBackground

videoWidget->setAttribute(Qt::WA_NoSystemBackground);
videoWidget->setAttribute(Qt::WA_TranslucentBackground); // NO EFFECT with these too

//In style.css doesn't work none of them
QVideoWidget {
    background: transparent;
    background-color: rgba(0,0,0,0);
}

Set the QVideoWidget geometry to be min the size of media is about to playing, but using QMediaMetaData.Resolution I get (-1, -1) as QSize. What I done:

QMediaPlayer* player = new QMediaPlayer;
player->setSource(QUrl(videoSrc));
player->setVideoOutput(videoWidget);
player->metaData().value(QMediaMetaData::Resolution).toSize() // it prints (-1, -1)

EDIT: I found that sometimes when videoWidget is shown for a little time the background is yellow, but after 1 second it becomes black

SGaist

Hi,

AFAIR, the video rendering will be done by native backend function which may completely ignore these hints/constraints.

For example, on macOS, the custom widget paint event will draw explicitly a black background before calling the base class implementation.

TheEnigmist

@SGaist
I see, so there is not way to manipulate it, or at least use some workaround to get rid off native background?

About MetaData, I found a bizzare behaviour. To get the resolution I need to use metaDataChanged signal from QMediaPlayer, but it works only if the file is on local system, if I load a file inside .qrc resource file I get (-1, -1).
I'm using Windows 11

SGaist

One possible way would be to create your own QAbstractVideoSurface and set it on the player in place of QVideoWidget.

TheEnigmist

@SGaist I want try this road, but I cannot include QAbstractVideoSurface, it says the file is missing...
Tried with VS 2022 and Qt Creator, same error

jsulm

@TheEnigmist said in Customize QVideoWidget and QMediaPlayer Metadata problems:

QAbstractVideoSurface, it says the file is missing

Did you add the needed module?
In case you use Qmake you need "QT += multimedia" in your pro file.

TheEnigmist

@jsulm Yes, alredy added it, and still it gives missing file error on include...
I'm on Win 11 with Qt 6.3.0

jsulm

@TheEnigmist said in Customize QVideoWidget and QMediaPlayer Metadata problems:

still it gives missing file error on include

Does this happen when you build your application or is it in QtCreator editor?

TheEnigmist

@jsulm In Qt Creator and in VS 2022 as well.

Qt Creator:

VS 2022:

EDIT: I found the problem... QAbstractVideoSurface has been replaced by the QVideoSink class in Qt6:
https://doc.qt.io/qt-6/qtmultimedia-changes-qt6.html

EDIT2: I think i will open two different topic since I found different "bug?"