Crash at Initialization

[ardaegeunlu]

When I first built the code on HoloLens, it was working fine with outputs of marker count to the debugger. However when I tried to run it again, with no changes, I started getting this error. (Deleted and reinstalled, same crash with the same stack trace. Though it magically? worked once again after reinstallation, not in the first try.)

Here is the stack trace:

'ArUcoDetectionHoloLensUnity.exe' (Win32): Unloaded 'C:\Program Files\Intel\Media SDK\libmfxhw32.dll'
Exception thrown at 0x76D02552 (KernelBase.dll) in ArUcoDetectionHoloLensUnity.exe: WinRT originate error - 0xC00D36B3 : 'The stream number provided was invalid.'.
MediaFrameSourceGroup::TryInitializeMediaCaptureAsync: MediaCapture is successfully initialized in shared mode.
MediaFrameSourceGroup::InitializeMediaSourceWorkerAsync: selected group has 2 media frame sources
MediaFrameSourceGroup::GetSensorType:: assuming SensorType::PhotoVideo per _mediaFrameSourceGroupType check (source id is 'Source#1@\?\DISPLAY#INT22B8#4&27b432bd&0&UID139960#{e5323777-f976-4f5b-9b55-b94699c46e44}{CDD6871A-56CA-4386-BAE7-D24B564378A9}')
MediaFrameSourceGroup::GetSubtypeForFrameReader: evaluating MediaFrameSourceKind::Color with format Video-NV12 @30000/1001Hz and resolution 896 x 504
MediaFrameSourceGroup::InitializeMediaSourceWorkerAsync: created the 'PhotoVideo' frame reader
'ArUcoDetectionHoloLensUnity.exe' (Win32): Loaded 'C:\Windows\System32\msvproc.dll'.
The thread 0x308 has exited with code 0 (0x0).
MediaFrameSourceGroup::InitializeMediaSourceWorkerAsync: started the 'PhotoVideo' frame reader
MediaFrameSourceGroup::GetSensorType:: assuming SensorType::PhotoVideo per _mediaFrameSourceGroupType check (source id is 'Source#0@\?\DISPLAY#INT22B8#4&27b432bd&0&UID139960#{e5323777-f976-4f5b-9b55-b94699c46e44}{CDD6871A-56CA-4386-BAE7-D24B564378A9}')
MediaFrameSourceGroup::InitializeMediaSourceWorkerAsync: sensor type has already been initialized!
Exception thrown at 0x76D02552 in ArUcoDetectionHoloLensUnity.exe: Microsoft C++ exception: Il2CppExceptionWrapper at memory location 0x0260F484.
The thread 0x6c8 has exited with code 0 (0x0).
Exception thrown at 0x64C8E1FE (HoloLensForCV.dll) in ArUcoDetectionHoloLensUnity.exe: 0xC0000005: Access violation reading location 0x00000020.

[ardaegeunlu]

It looks like the first update was called before the initialization of sensors were finished, adding extra checks resolved the problem. ✔️

[noxer]

@ardaegeunlu I've got the exact same problem, what exactly did you do to fix it?

[ardaegeunlu]

I added a grace period of 2 seconds (probably an overkill) after the call to StartHoloLensMediaFrameSourceGroups(), and only after that started making calls to UpdateHoloLensMediaFrameSourceGroup().

[noxer]

Okay, I ended up doing the same. Thank you.

[doughtmw]

As per the comments from @ardaegeunlu, I've added a fix to the main repo for this issue. Thanks for your help!