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Qt multimedia player

  • Hi, I have developed a media player using QTmultimedia in Windows. But I found different beahviour second compiler and backend engine. For example if I use msvc and multimedia foundation engine I have no problem to scroll video surface while if I use mingw with directx engine the video surface not scroll well. Only audio is scrolled and video disappear.. I world like to understand why custom video surface example runs well only if I compile with mscv2010 and later,while same example compiled with mingw disabling video showing. I suppose it is the directx backend but if so I guess there is a bug some where. Anyone has tried custom video surface example present in qt , with directx engine?

  • I have not used DirectX directly with Qt. However, I have used the irrlicht engine which I believe defaults to DirectX under windows (I believe... I could be wrong).

    I have noticed that you really need to be careful when using a 3D based graphics engine because Qt behaviors can disrupt the rendering process. If the Direct3D interface requires custom rendering behavior when scrolling this could be the issue because the scene must be drawn every couple of microseconds in order to prevent greying out or grey flashes on the control (widget).

    "Here": is an example of an issue I had. My workaround was to insert a call to my scene rendering method in the custom style I was using to render UI components. (I have yet to see if it works but I suspect it will).

  • Hi thanks for response.

    I have found a work around because I showed subtitles on frame and the only way to do that was using video surface instead video widget, but I needed to use directx for other kind of formats not supported by wmf. My solution if Anyone needs was to alternate the videooutput for rendering and reactive videosurface. With stop/play and alternate Qvideowidget with videosurface each time you scroll solve the issue..but its very strange..I hope Anyone has tested this

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