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iOS app random crash when stopping CameraDevice with Cloud Recognition

By masonhsiung on Fri, 01/04/2013 - 07:53

 

Hi, We encounter a random crash when iOS app is stopping CameraDevice with Cloud Recognition(without Cloud Recognition it doesn't crash) Here are the crash reports we got from iPhone4, iOS5/iOS6(yes, this happens on both iOS5/iOS6) - iPhone4, iOS5==Thread 4 name:  Dispatch queue: com.qualcomm.AR.videoqueueThread 4 Crashed:0   xxxxxxxx                        0x001ff7a0 0x3a000 + 18574401   xxxxxxxx                        0x001fd29c 0x3a000 + 18479642   xxxxxxxx                        0x0016be66 0x3a000 + 12529663   xxxxxxxx                        0x0017014c 0x3a000 + 12700924   xxxxxxxx                        0x0016c472 0x3a000 + 12545145   xxxxxxxx                        0x0016dbca 0x3a000 + 12604906   xxxxxxxx                        0x0016d036 0x3a000 + 12575267   xxxxxxxx                        0x001a0a80 0x3a000 + 14690568   AVFoundation                   0x33aea244 __74-[AVCaptureVideoDataOutput _AVCaptureVideoDataOutput_VideoDataBecameReady]_block_invoke_0 + 2209   libdispatch.dylib              0x308b6c52 _dispatch_call_block_and_release + 610  libdispatch.dylib              0x308c1ca4 _dispatch_queue_drain + 26811  libdispatch.dylib              0x308c1b12 _dispatch_queue_invoke$VARIANT$up + 3012  libdispatch.dylib              0x308c2784 _dispatch_worker_thread2 + 20813  libsystem_c.dylib              0x34005df4 _pthread_wqthread + 28814  libsystem_c.dylib              0x34005cc8 start_wqthread + 0== - iPhone4, iOS6==Thread 8 name:  Dispatch queue: com.qualcomm.AR.videoqueueThread 8 Crashed:0   xxxxxxxx                        0x00221790 0x5c000 + 18574241   xxxxxxxx                        0x0021f28e 0x5c000 + 18479502   xxxxxxxx                        0x0018de5a 0x5c000 + 12529543   xxxxxxxx                        0x00192140 0x5c000 + 12700804   xxxxxxxx                        0x0018e464 0x5c000 + 12545005   xxxxxxxx                        0x0018fbbc 0x5c000 + 12604766   xxxxxxxx                        0x0018f028 0x5c000 + 12575127   xxxxxxxx                        0x001c2a74 0x5c000 + 14690448   AVFoundation                   0x31b0316e <redacted> + 2549   libdispatch.dylib              0x37aba11c <redacted> + 810  libdispatch.dylib              0x37ab9996 <redacted> + 14211  libdispatch.dylib              0x37ab9890 <redacted> + 3212  libdispatch.dylib              0x37ac8212 <redacted> + 19013  libdispatch.dylib              0x37ac83b4 <redacted> + 8014  libsystem_c.dylib              0x37762a0e <redacted> + 35815  libsystem_c.dylib              0x377628a0 start_wqthread + 4== Here is the code showing how app stops CameraDevice.==if(APPSTATUS_CAMERA_RUNNING == ARData.appStatus) {    QCAR::TrackerManager& trackerManager = QCAR::TrackerManager::getInstance();    QCAR::ImageTracker* imageTracker = static_cast<QCAR::ImageTracker*>(trackerManager.getTracker(QCAR::Tracker::IMAGE_TRACKER));        QCAR::TargetFinder* targetFinder = imageTracker->getTargetFinder();    assert (targetFinder != 0);        targetFinder->stop();    targetFinder->clearTrackables();        targetFinder->deinit();     imageTracker->stop();        QCAR::CameraDevice::getInstance().stop();    QCAR::CameraDevice::getInstance().deinit();        QCAR::onPause();}== I suspect that it might be caused by Cloud Recognition(the scanline effect)...Any idea? Thanks!

masonhsiung

Mon, 01/07/2013 - 02:41

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The forum system seems having a small bug on showing the last one who replys the post.

Before I reply this post, the last one was

==

masonhsiung

Wed, 01/09/2013 - 08:47

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Hi,

I still can't find a workaround for this issue.

Could someone please give me a hint?

Thanks a lot!!

 

Hi masonhsiung,

Thanks for this and sorry for the delay in replying.  Forum gremlins I am afraid :(

I can investigate the crash for you.

Please can you upload somewhere and post a link so I can look into this further?

thanks,

N

Hi NalinS,

I just got another finding.

I get rid of NinevehGL framework dependency, switch back to use QCAR sample way(QCARUtils) in our app.

Our app still crashes, here is the crash report, and they look quite similiar.

Hi NalinS,

Sure no problem, below is the project tarball, this project doesn't have any rendering logic.

http://db.tt/YCgV5ZWn

This project uses the way(QCARUtils) from QCAR sample to start QCAR camera by default.

Hi Mason,

I was able to reproduce the issue, however it is going to be very difficult to find a way forward here because it is iPhone4 only and it is quite unpredictable as to when exactly it crashes.