[Interest] Send Video output to specified display

[Rutledge Shawn]

On 25 Jun 2014, at 07:26, Vinoth Kumar <vinoth.k.kumar at gmail.com> wrote:

> Hi,
> 
> I have 2 different displays (1 LCD and 1 HDMI) connected to my device. Is it possible in Qt to direct the output of my video playback to a particular display. Does QtMultimedia have any provision for this?

There are a couple of examples which iterate the QScreen objects and put windows on each of them:

qtbase/examples/opengl/hellowindow is a low-level one, not using either widgets or Qt Quick

qtbase/tests/manual/qscreen puts up widget-based windows on each screen, showing information about the screen.  You should probably test it to see what happens on your system.

If you are writing your app with Qt Quick, we don’t have declarative API for putting windows onto particular screens yet, so you will need to do this in C++, for example in main() where you create the QQuickView or QQmlApplicationEngine.  QQuickView inherits QWindow, so you should be able to set the screen and also set the geometry of the window to that screen’s geometry() before showing the window, like the hellowindow example does.  The reason is that in a typical multi-monitor desktop environment, the user controls the arrangement of the monitors into a virtual desktop, so it’s not enough to define which screen you want the window to be associated with.  The window could “belong” to one screen but actually be overlapping onto several screens at the same time.  And on a desktop application you don’t usually need to control which screen the window goes to anyway; you let the user drag it there.  So controlling which screen it goes to is possible but usually needs both steps: setting the screen and setting the geometry.

What kind of device are you developing for?