General and Desktop

@mrjj Qt 5.12.4 (GCC 9.1.0, 64 bit) installed on MSYS.

@sgaist The version is Qt opensource-windows-x86-5.13.0.

It's working now. The problem was linux-rasp-pi3-g++'s qmake.conf file. If we're building Qt for RPi3 we need to create a new qmake.conf based on linux-rasp-pi-g++ and replace the build flags with those from linux-rasp-pi3-g++. The fix is described in this guide.

@kshegunov I'm sorry, the example i wrote works fine. I found the mistake in my algorithm, the input buffer was recreated, instead of the entries ... input = QVector<fftw_complex>(12); // this doesn't work! ... Thanks anyway! EDIT: To complete the answer, the FFTW library has a "New-Array Execution" function, where the input and output buffer can be set when executing the plan. And with QVarLengthArray you can handle the arrays easily with high performance. QVarLengthArray won't check if the data is shared.

Hi @kakyoism Running qmake -project fails with complaints about environment setup. This was solved by adding qmake -project only creates a stub. You have to edit it by hand afterwards to get a functional project file. Setting up the environment is nothing anyone else can do for you, don't you agree? And deployment is a necessary step on every platform, I agree that this could be a bit more automated (like a make deploy step). But unfortunately we don't have it. I feel that they could be easily fixed in qmake with its generated projects. As Qt is switching to CMake, qmake will only get fixes from now on. Adding more functionality is quite unlikely. Regards

So it turns QString into a picture to translate QString AppCore::getImage(QString addressFile) { QImage myImage(addressFile); QByteArray bArray; QBuffer buffer(&bArray); buffer.open(QIODevice::WriteOnly); myImage.save(&buffer, "JPEG"); QString image("data:image/jpg;base64,"); image.append(QString::fromLatin1(bArray.toBase64().data())); QImage testImage(image); qDebug()<<"myImage.size() : "<<myImage.size(); return image; }

ohhh yeah it worked thanks man!!

@mrjj perfect! Thank you! You are great!

@august-wiener said in How to save image (about 36 mb) to db via QSqlQuery?: 36 mb for image is not so much. For a file, 36 MB is not too much. For a single field in a relational database, 36 MB is extremely unusual. You will probably have a lot more luck saving the image to a file, and just retaining the filename in the database as a short string. This is the much more common way to do it. The SQL database isn't really designed around storing large binary blobs, and neither are the associated libraries.

@r-p-h said in OpenCV 4.1.1 Imread() & Imwrite() Crashes Program ?: now everything is working fine. so please don't forget to mark your post as solved! Thanks.

The "cpplang" Slack is quite active with C++ developers, and it has a Qt channel. The Qt channel specifically isn't super active, but there are always a few folks around. https://cppalliance.org/slack/

And I don't think you are going to be able to do that with QUndoView as it is currently implemented. You should check its implementation and create your own View/Model combo that fits your need. This is going to be faster.

5.13.1 is not released as an stable Qt version and I'm using 5.13.0 (latest stable version) so I applied the patch. Thanks!

@fem_dev Hi Case 2 is not possible with the DLL/so files alone. It has to be loaded via some other app using QPluginLoader/QLibrary

The problem is officially a bug: bug 1070

@oshio Thank You, you'ra are very usefull!!!