App crash on QImage::transformed (Qt 5.10)
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Hello. I have app that gets images from photo cameras for future processing. Initialy I get images as QByteArray buffer and then process them as follows:
if(buf_.isNull()) return; QImage image; QMatrix rm; rm.rotate(90);//I need vertical aligned picture image.loadFromData(buf_);//buf_ is raw data QByteArray if(image.isNull()) { emit error(); return; } QImage trans_image = image.transformed(rm); trans_image.save(path_, "JPG", 100); buf_.clear();Regulary I get crash on QImage trans_image = image.transformed(rm), sometimes it takes 5-6 images, sometimes 50-60.
Call stack looks like that:
1 qt_memrotate270_tiled_unpacked<unsigned int> qmemrotate.cpp 212 0x1b2ec6c 2 qt_memrotate270_template<unsigned int> qmemrotate.cpp 275 0x1b2ec6c 3 qt_memrotate270 qmemrotate.cpp 315 0x1b2ec6c 4 qt_memrotate270_32 qmemrotate.cpp 377 0x1b2ecd3 5 rotated90 qimage.cpp 4520 0x1a07c3f 6 QImage::transformed qimage.cpp 4627 0x1a0a502 7 QImage::transformed qimage.cpp 2792 0x1a0b1ce 8 Camera::processImage camera.cpp 293 0x438bea ...Image variable looks pretty ok in debugger, not Invalid or anything like that, start of the buffer looks like proper jpeg header.
Image size is 4000*6000px.
It doesn't seem to be some memory leak problem, once it crashed when program only allocated around 100mb of RAM.
Also this processing works in thread, maybe it is important.What can be reason for such crash and how can I deal with it (at least catch an error and tell user of it to avoid segfault)?
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Hello. I have app that gets images from photo cameras for future processing. Initialy I get images as QByteArray buffer and then process them as follows:
if(buf_.isNull()) return; QImage image; QMatrix rm; rm.rotate(90);//I need vertical aligned picture image.loadFromData(buf_);//buf_ is raw data QByteArray if(image.isNull()) { emit error(); return; } QImage trans_image = image.transformed(rm); trans_image.save(path_, "JPG", 100); buf_.clear();Regulary I get crash on QImage trans_image = image.transformed(rm), sometimes it takes 5-6 images, sometimes 50-60.
Call stack looks like that:
1 qt_memrotate270_tiled_unpacked<unsigned int> qmemrotate.cpp 212 0x1b2ec6c 2 qt_memrotate270_template<unsigned int> qmemrotate.cpp 275 0x1b2ec6c 3 qt_memrotate270 qmemrotate.cpp 315 0x1b2ec6c 4 qt_memrotate270_32 qmemrotate.cpp 377 0x1b2ecd3 5 rotated90 qimage.cpp 4520 0x1a07c3f 6 QImage::transformed qimage.cpp 4627 0x1a0a502 7 QImage::transformed qimage.cpp 2792 0x1a0b1ce 8 Camera::processImage camera.cpp 293 0x438bea ...Image variable looks pretty ok in debugger, not Invalid or anything like that, start of the buffer looks like proper jpeg header.
Image size is 4000*6000px.
It doesn't seem to be some memory leak problem, once it crashed when program only allocated around 100mb of RAM.
Also this processing works in thread, maybe it is important.What can be reason for such crash and how can I deal with it (at least catch an error and tell user of it to avoid segfault)?
@Crazy-Sage said in App crash on QImage::transformed (Qt 5.10):
What can be reason for such crash and how can I deal with it (at least catch an error and tell user of it to avoid segfault)?
hard to say. In C/C++ it's easy that an arbitrary (on first sight unrelated) part of your code can cause be influencing and cause a crash, since it is possible to modify the memory from anywhere in your application.
You can try to isolate the code and try to reproduce. I bet it wont crash, since the code part you've posted looks good.
But also threading is a highly possible cause. You need to make sure that you protect resources that are shared among threads. (e.g. with a mutex).
Or at least you need to make sure that each thread operates on a separate copy of data. So that no other thread interferes and is reading/writing the same data at the same time.
