zxing-cpp: Assert in RegressionLine::evaluate due to empty points

15:00:41: Starting D:\DEV\Qt\build-zxing-qt-Desktop_Qt_6_3_2_MSVC2019_64bit-Debug\debug\zxing-qt.exe...
QML debugging is enabled. Only use this in a safe environment.
Aztec|Codabar|Code39|Code93|Code128|DataBar|DataBarExpanded|DataMatrix|EAN-8|EAN-13|ITF|MaxiCode|PDF417|QRCode|UPC-A|UPC-E|MicroQRCode
15:00:43: D:\DEV\Qt\build-zxing-qt-Desktop_Qt_6_3_2_MSVC2019_64bit-Debug\debug\zxing-qt.exe crashed.

Also, BarcodeFormat::Any is missing at ZXingQtReader.h

Any			= LinearCodes | MatrixCodes

PS: build: 6.3.2 Qmake MSVC 2019 64bit PS2: Crash also on 6.5.0: https://github.com/zxing-cpp/zxing-cpp/discussions/559#discussioncomment-5826563

Edit: Commenting MediaDevices & derived code (comboBox model etc) avoids the immediate crash but the app hangs until it crashes.

Not having a proper barcode (or any) in front of the camera seems to make it crash quicker.

Disabling Try Harder and Matrix Codes “improves” when no barcode is detected but hangs (not like before, at least) when it can’t easily decode the barcode

Having a barcode in front of the camera avoids the crash for some time

About this issue

Original URL
State: closed
Created a year ago
Comments: 21 (13 by maintainers)

Commits related to this issue

DataMatrix: fix assert in RegressionLine::evaluate (fix #593) — committed to DreamForTek/zxing-cpp by axxel 8 months ago

Most upvoted comments

I dont know if this helps…

I think it did help. 😃. It made me realize that it is indeed quite possible that I could end up with a set of points who’s regression line is in fact further away than 3 pixels from all individual points. I still don’t understand how the code could end up placing those random points into the line but that is enough insight for me to fix this without feeling that I missed something completely.

axxel on Oct 27, 2023

Thanks for the detailed set of screenshots. You seem to know your way around a debugger. Would it be possible for you do something along the lines of what I described here? The goal would be to generate a png-file from your camera input that I can then use to reproduce the issue on my machine. This (second) crash has likely nothing to do with Qt.

The immediate crash might but to get closer to that problem, a trace of that crash would be required as well.

axxel on Jul 28, 2023