"We offer new support options and therefor the forums are now in read-only mode! Please check out our Support Center for more information." - Vuforia Engine Team

Crash on QCAR::CameraDevice::getInstance().stop()

By marchinram on Wed, 06/20/2012 - 17:07
Hello, While debugging an app I'm working on I noticed I'm gettin alot of crashes on this line: QCAR::CameraDevice::getInstance().stop() Does anyone know what may be causing this? Thanks

Hi marchinram, I found some time to knock up a quick modal viewcontroller sample last night. It seems to work (iOS4 and 5) without the errors you are reporting. Take a look to see how this differs from your implementation. It's not the most beautiful code but it illustrates the solution.

marchinram

Tue, 10/25/2011 - 16:51

Permalink

Cool, thanks, I will give this a shot, are you using automated reference counting in your project, cause I don't see any releases. Our project is built against ios 5 but the fobjc-gc setting is set to unsupported, not sure if that can cause any issues.

[QUOTE=marchinram]are you using automated reference counting in your project, cause I don't see any releases.[/QUOTE] No I'm not using automated reference counting a) I have a class property without retaining setters, so things I want retained don't get released and b) I did say it wasn't beautiful

marchinram

Wed, 10/26/2011 - 17:58

Permalink

I think I have an idea of what is causing the crashes, still not sure why they are happening but here's what's going on. First there is a main view controller in a navigation controller, you press a button then it pushes a help screen view controller on the navigation controller.

marchinram

Thu, 10/27/2011 - 05:26

Permalink

I changed the ImageTargets sample project to use your code to try and isolate what's happening and I'm still getting that same crash when the camera is stopped. I'm also getting a QCAR::State call in the trace, log is below.

marchinram

Thu, 10/27/2011 - 06:02

Permalink

I'm also seeing this crash quite a bit, its and EXC_BAD_ACCESS, I modified the image targets sample by copying and pasting your code and adding the instance variables needed. Thread 7 Crashed: 0 libsystem_c.dylib 0x362d2ae4 pthread_mutex_lock + 24 1 ImageTargets 0

marchinram

Thu, 10/27/2011 - 09:44

Permalink

I was able to get the Framemarkers sample to run modally using your code sample with success. I noticed that the framemarkers only has a config.xml tracker and no qcar-resources.dat file, which is different from the image targets sample and my code.

Hi marchinram, I think you're clutching at straws on the xml/dat. The demonstration I put together never crashed, so think about what is different with yours - is it still the popToRootViewControllerAnimated?. If you're still struggling, then if you'd like to make a 'bare bones' version and send