Details
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Bug
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Resolution: Fixed
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P3: Somewhat important
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5.15.8
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None
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IMX 6q running linux Buildroot 4.5.9 kernel 5.4-2.3.x-imx
GStreamer 1.20.1
Qt 5.15.8 with Qt Multimedia at commit bd29c87027637a013f2c5e3b549fcda84e4d7545
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Linux/Other display system
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f398aac61 (dev), 82397169f (6.7), 84156a1d7 (6.6), 64f8bf3eb (tqtc/lts-6.5), f84fe0247 (dev), 52ba122f6 (6.7), c23f11662 (6.6), 6a36057b8 (tqtc/lts-6.5), 6b950406b (tqtc/lts-5.15)
Description
Target information:
Problem information:
When accessing a linux v4l2 camera via QCamera, and trying to access any of the parameters via the QCameraImageProcessing class, it does not work and produces the following warning:
Unable to open the camera "/dev/video0" for read to get the parameter value: "Device or resource busy"
Attached is a minimal reproducer, although this problem is platform (and possibly driver) specific
This is due to Qt trying to acquire the /dev/video0 device once gstreamer has acquired it. Modifications to the qt CameraBin gstreamer plugin were tested to resolve this which were successful. This was done by either using g_object_set(...) to change the parameters that the v4l camerabin GstElement provide or by requesting the open device file descriptor from gstreamer with g_object_get(...)