iOS app random crash when stopping CameraDevice with Cloud Recognition
iOS app random crash when stopping CameraDevice with Cloud Recog
In our app, we want User have the same scanline effect with/without cloud recognition, which means we use both real/dummy Cloud recognition together in our app.
It seems that scanline does cause crash specifically on iPhone4(it doesn't crash without scanline), and there is no workaround for this issue(can't disable the scanline while cloud recognition is ON).
I guess to prevent this issue, we probably need to render the camera background by ourselves.(getFrame and render).
It's gonna take some time though...
Thanks for your reply! :)
Hi Mason, I was able to
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.
My understanding is that you are using a "dummy" Cloud Reco with empty keys purely in order to have the scanline feature right?
Does it crash without this scanline? If not then my suggestion is that it might be more sensible to write your own such feature / effect, and most likely this will be quicker for you.
We will investigate this issue further, however I cannot promise any timescale for any resolution here.
Hope you can understand :)
Hi NalinS, Sure no problem,
Sure no problem, below is the project tarball, this project doesn't have any rendering logic.
This project uses the way(QCARUtils) from QCAR sample to start QCAR camera by default.
You can easily switch between QCAR and NinevehGL by modifying the predefine header file.(ARApp-Prefix.pch)
In order to reproduce the random crash, you need to repeatedly start/stop the QCAR camera.
The crash happenes on (it seems that it's an iPhone4 specific issue.)
- iPhone4, iOS5.1.1
- iPhone4, iOS6.0
I use StoneAndChips dataset and empty access/secret key for showing scanline/points.
Hi NalinS, I just got another
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.
http://pastebin.com/MNyqG3eS (iPhone4, iOS5.1.1)
The main thread stopped at stopCamera
7 ARApp 0x0000b15e -[QCARutils stopCamera] (QCARutils2.mm:689)
The line 689 is
The crashed thread is the same with the previous crash report. (dispatch queue: com.qualcomm.AR.videoqueue)
Thanks a lot!!
Hi NalinS, Thanks for the
Thanks for the reply :)
I have uploaded the crash report to pastebin, here is the link
Please let me know if you need any further information.
BTW, I forgot to mention that the app in fact integrates the 3D framework NinevehGL, which is responsible for executing the rendering loop.(drawView method instead of renderFrameQCAR).
Although, I don't think that NinevehGL causes this issue :). Just for your information.
Hi masonhsiung, Thanks for
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?
The forum system seems having
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
Dec 13 2012 10:38pm
which I don't think "intoching1" did reply this post...
Anyway, does anyone have any idea on this issue?
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