Darkly Labs Community

Lightburn crashing when selecting E2 camera

I can’t use the E2 camera in LB. Whenever I select it from the drop-down list in LB, it crashes immediately. I can use the E2 camera from the Windows 10 camera app, so it’s not a (camera) driver issue.

This is on an old Thinkpad T60p, with a FireGL v5250 graphics card. I suspect that the driver trips over a setting in ChoosePixelFormat. Anyway, would it be possible to let me simply disable hardware acceleration, and use software rendering?

Here is the stack trace when LB crashes:

atio6axx!DrvPresentBuffers+0x747bc0
atio6axx!DrvPresentBuffers+0x171db3
atio6axx!DrvPresentBuffers+0x10147
atio6axx!DrvPresentBuffers+0x9ffa
atio6axx!DrvPresentBuffers+0x7d73
atio6axx!DllMain+0xd35f
atio6axx!DrvDescribePixelFormat+0x112
opengl32!LoadAvailableDrivers+0x315
opengl32!wglDescribePixelFormat+0x139
opengl32!wglChoosePixelFormat+0x85
gdi32full!ChoosePixelFormat+0x39
qwindows+0x378c0
qwindows+0x35f9e
qwindows+0x37577
qwindows+0xb69b
qwindows+0xbf9a
qwindows+0xb8f9
Qt5MultimediaWidgets!QCameraViewfinder::tr+0x2b7
Qt5MultimediaWidgets!QCameraViewfinder::tr+0x3557
dsengine+0x21509

- Daniel

From the stack trace, that crash is happening inside the ATI graphics driver. I would suggest seeing if a newer driver is available.

You said “this is on an old…” - how old? What OS are you running?

The T60p dates from 2007, and was one of the top of the line Thinkpads back then. No, there isn’t a newer driver available. 

Os is Windows 10 64bit

Still, as I said, the E2 cam is working with other software, like Skype or Windows 10 Camera App. So I’m sure it’s possible to use it. The crash happens in the driver, yes, but possibly due to an issue with the parameters to

 

ChoosePixelFormat. Again, it seems to be due to selecting a OpenGL pixel format, so one could simply use software rendering to by-pass it. A simple option would be sufficient. 

When asking if there was an updated driver, I meant for the FireGL card, not the T60.

From the information I can find, GDI32Full is a Windows 10 DLL, so the operating system is choosing to make that OpenGL call, not LightBurn. Technically, the Qt Framework we’re built on is calling Windows, which is then calling GDI, which is calling OpenGL, and that is ultimately calling into the ATI driver, which is crashing. We don’t have control over any of that code.

LightBurn is entirely software rendered, but it’s possible that the Qt framework under the hood is using some hardware acceleration in the multimedia engine for doing color format conversion - most cameras present data in YUV or YCbCr format.  It’s quite expensive to convert the frames to RGB, but most graphics cards will do it more or less for free. If this is indeed what’s happening I doubt there’s much that I can do about it, though I’ll investigate.