CODEWITHSUNDEEP
qtcamerams-media-foundationqtmultimedia
Andrej Fogelton
Andrej Fogelton

Reputation: 123

Which dlls are needed for Qt multimedia QCameraInfo::availableCameras(); to return the list of cameras?

On Windows 10 N, the windows media foundation and player are missing and QCameraInfo::availableCameras(); returns empty list. The mediaservice plugins are copied correctly both dsengine.dll and wmfengine.dll. The app works on other windows machines. You can try it blinkingmatters.com Qcamera object is defined, the empty list is not returned because of that issue.

Which dlls I need to add to my deployment to get qt multimedia to return correct list of cameras? I tried to coppied all dlls from windows/system32 which starts with "mf" mf*.dll without success. At least once I catch even a crash caused by Access violation (Code: c0000005). I am using precompiled qt library 5.12.0 64bit msvc2017 so I do not know more, with the stack trace:

Qt5Core!QString::QString

dsengine

Qt5Multimedia!QMediaServiceProviderHint::device

Qt5Multimedia!QCameraInfo::availableCameras

Upvotes: 0

Views: 554

Answers (1)

Roman Ryltsov
Roman Ryltsov

Reputation: 69642

Windows 10 N comes with no Media Foundation. You cannot (not allowed to) copy system32 DLLs to resolve the problem, instead the system needs a Media Feature Pack installed to make the Media Foundation APIs available.

Upvotes: 1

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