How to decompress compiled qt resource file with rcc extension?
Since the accepted answer did not meet my needs, I thought I'd post my experience in this.
I wrote a node module that will extract PNG files from QT binary rcc files. It is available on npm as png-extractor if you are interested.
rcc is not a file format. It's Qt's resource compiler. It doesn't create a resource file either. It converts the resources specified in your qrc file into a C++ source file and lets C++ compiler compile it into object code to be linked into your app.
Look for qrc_yourproject.cpp in your build directory to see what's produced. Do not try to access the objects/structures defined in the file directly since Qt may change how they are constructed in later versions. Use Qt's resource management calls to do that.
Related
I have QML file that has been embedded into a dll. I think it was done something like this
How can I embed a Qt resource into a .dll file?
(The second answer).
Is there anyway to split out the QML file to obtain the source code? I am not very familiar with QT framework
If it's embedded via *.qrc, then it's NOT compatible with standard windows/linux (.dll/.so) resource formats. qrc is compiled as xxx_qrc.cpp file and embedded by linker as .obj file with static initialization code. I.e. it's just part of the binary. You can access "contents" of qrc via QFile with "qrc:/." URL. But for that, you have to load DLL with resources embedded in current process, because qrc is hooked up in static initialization (aka DllMain in Windows). Something like:
QLibrary lib("./library.dll");
if (!lib.load())
throw exception(lib.errorString().toStdString());
QFile resource(":/resource.qml");
if (!resource.open(QIODevice::ReadOnly))
throw exception(resource.errorString().toStdString());
resource.copy("./exported.qml");
To explore currently loaded virtual qrc file system tree, you can use QDir(":/"). I guess it's pretty easy to figure out the rest from here.
And of course - you have to be aware what sort of DLLs you are loading into your process, as they may contain arbitrary code that will be executed as you call QLibrary::load!
I use CMake to build Qt project with internatiolization support. Using qt5_create_translation I can create *.ts files into the source directory and *.qm files into the build directory.
I want to reduce the number of files I should to distribute. Storing translation files :/translations/*.qm into the Qt resources is straitforward solution.
But during build process names of the resources are generated automatically and there is no native way to emplace them into the *.qrc file automatically.
How to achieve desired using, say, add_custom_command or something else?
Qt's qrc file is just xml files. Thus you can an external tool to add it.
A pure cmake solution could be:
Create a dummy resource file named #TRANS_FILE#
Add this file to your qrc file
Fetch the name of the translation file into a variable. Don't know how.
Use cmake's configure_file to replace the dummy resource name
Example:
set(TRANS_FILE ${NameOfTranslationFile})
configure_file(infile.qrc outfile.qrc #ONLY)
I want to translate a program; but its language files (.qm) are in a .rcc file.
The program is not mine, so I haven't got any .qrc file.
Before asking this question, I have searched this site about this issue; but I don't attain anything.
Is there any way to extract/decompile it?
You can take my tool RccExtended - it based on the official Qt resource compiler with additional function to decompile binary resources.
Usage example:
cd \Path\To\MyQtResources\
rcc --reverse
Decompiler will unpack all .rcc files in the current directory, generate .qrc files and make.bat file to compile resources back to the binary format.
There isn't a supported way to decompile it as far as I'm aware, but it's a binary file format that can be read and handled. There's a nodejs example of how to read the file and extract PNGs on github: https://github.com/gcochard/png-extractor. It may be possible to extend that method out for the .qm files.
However there's other issues with attempting to add more translations to a Qt application without having the code, depending on the language you're attempting to add, how the developer has exposed the other languages etc.
According to the Qt wiki, both definitions seem very similar to me..
The rcc resource compiler parses the XML and generates C/C++ code
The uic reads an XML format user interface definition (.ui) file as generated by Qt Designer and creates a corresponding C++ header file
So they each take an xml file and make it into c++. So what's the difference that you would use one over the other?
(Incidentally I'm looking to use pyQt with QT Designer (&pyrcc4?) to make a simple GUI for an existing DLL)
Thanks!
rcc is a Qt resource compiler: the Qt resource system is a platform-independent mechanism for storing binary files in the application's executable.
uic is Qt user interface compiler: it creates a corresponding C++ header file from ui file generated in Qt Designer
I use fopen(filename.c_str(), "rb"); in Qt with images resources.
But fopen wants a full path. It doesn't work if my filename is :/images/img.png!
fopen is not part of Qt. Qt's resource system only works with Qt classes. See the Qt documentation of Using Resources in the Application for details.
The Qt classes which work for resources first check if the given filename starts with the resource marker (:) and if so, they look up the resource internally (no physical file is opened!), otherwise, they open the physical file. Note that resources are included in the source code of your application (as a simple array of bytes) during compile time (using the Qt resource compiler) and read using a special resource reader in Qt internally, which can treat the resource file as it would be a physical file, but it still isn't.
What happens if you pass a resource file path (starting with :) to fopen? fopen tries to read a physical directory called : and searches in this directory for the subpath you provided. Of course, no such directory exists on your harddrive, since the file is part of your executable file. (And please don't try to read the resource file manually from within the executable by opening the executable using fopen and seeking to the resource!)
In your concrete situation: Are you trying to read the image using an external image reader? Qt has its own PNG reader. Just call the QImage(QString filename) constructor.