Unable to connect the video probe in the player example

[Alexandra]

Hello. I ran the Media player example on Windows 10, opened .mp4 file and got this message in the console:

D:\Programs\QT511\Examples\Qt-5.11.1\multimediawidgets\build-player-Desktop_Qt_5_11_1_MSVC2015_64bit-Debug\debug\player...
Supported audio roles:
qt.multimedia.plugins.directshow: Failed to connect the audio sample grabber
qt.multimedia.plugins.directshow: Unable to connect the video probe!

Why doesn't the video probe work? I want to get assess video frames and process them. How can i do this? Thanks for answers.