OpenCV 2.4 staticlib link still relies on DLL? [windows] - c++

My system is Windows 64bit, and I am using VS 2013. I am using the latest OpenCV 2.4 build for Windows.
I am trying to compile a simple C program which uses OpenCV 2.4. The dynamic link version works well. But I need a static linked one so I think I can just copy this one executable to my working environment.
When I try to run my statically linked executable, the program cannot read my video file, but does not throw exceptions of any kind either. But if I put opencv dlls into my program's directory, the programm will work.
I have set the additional libraries path to include opencv\build\x64\vc12\staticlib. I have set the Runtime Library to Multi-threaded, but I think I still missed some option. I just could not figure it out.

Here's the question I posted on OpenCV's forum. To summarise:
Build your own static library from scratch.
Update
Re-post the steps from the post:
Build static ffmpeg
Build static opencv and static link to ffmpeg
Build the program and static link to the opencv & ffmpeg libraries
Caveats: You may face legal issues if you statically link to the ffmpeg libraries.

Related

How do I setup a Codeblocks project on Windows 10 to compile and link a static SFML project?

My advance appologies for being hopeless at Windows development. I am by no means a Windows developer and my understanding of how to write, compile and link C++ code on a Windows system is limited to say the least.
I am having difficulty trying to compile and link a SFML project on a Windows 10 system with the CodeBlocks IDE.
I am trying to link this project with static linking, not dynamic linking. Again I have virtually no idea how the two different methods work in detail, I just know that if I ship a static linked binary to another Windows 10 user it is much more likely to "just work" on their system.
List of things I did:
Downloaded the latest version of CodeBlocks with MINGW integration.
Installed, default options
Downloaded the latest version of SFML (32bit MINGW version)
Extracted the zip file (SFML) to my home directory
Created a new codeblocks project (console application) and followed the instructions to set the compiler and linker options
https://www.sfml-dev.org/tutorials/2.5/start-cb.php
It works fine for dynamic linking, but requires me to copy the .dll files to the same dir as the produced executable file (produced from compilation of my C++ code).
I tried to change to static linking, changing the names of the linker libs with the -s or -s-d suffix, and adding the define SMFL_STATIC option to global (release and debug) options. I also added the opengl32, freetype, winmm and gdi32 link libs, before their respective sfml link libs.
When trying to compile I get the following linker errors
cannot find -lfreetype
cannot find -lsfml-graphics-s-d
cannot find -lsfml-window-s-d
cannot find -lsfml-system-s-d
in Release mode, similar errors are produced.
What am I doing wrong?
My hunch would be that you either have the wrong compiler (see below) or you haven't defined the library directory as mentioned in the linked tutorial.
There are four common things to consider when using SFML (and essentially any other C++ library) on Windows.
Compiler versions have to fully match
Make sure to not mix x86 and x64
Settings need to be specified for the correct configuration
When linking libraries statically, you also need to link the dependencies
Compiler versions have to fully match
Since C++ doesn't have a standardized ABI, the generated libraries will never be reusable between compilers. Yes, sometimes "it works", but it can break at any point and there's no guarantee.
We strongly recommend to either use the compilers linked on the SFML Download page or build SFML from source with your current compiler.
If you got the latest stable Code::Blocks version with MinGW as stated, you should also be able to get a snapshot build of SFML, which should be using the same compiler.
Note: One exception to this rule is Visual Studio, where VS 2017 binaries are compatible with VS 2019 (and maybe VS 2022?).
Make sure to not mix x86 and x64
When you download a 32-bits (x86) version of SFML, you also need a 32-bits version of your compiler. When you download a 64-bits (x64) version of SFML, you also need a 64-bits version of your compiler.
Make sure you double check your compiler configuration that you've selected the correct bit-ness.
Note: For Visual Studio you need to select the correct compiler architecture in the IDE, usually positioned right next to the run button.
Settings need to be specified for the correct configuration
Project configurations are usually spread across the matrix built from the types:
Debug / Release / All
x86 / x64 (for VS)
Make sure when you add the settings for library paths and include paths that it's not just set for debug or release and ends up missing in either or the other configuration.
Also make sure you're not setting up debug libraries (with the -d suffix) in release mode or release libraries (without any suffix) in debug mode.
When linking libraries statically, you also need to link the dependencies
The SFML static libraries don't contain any symbols of any of its dependencies, that means, in your final application you have to link static SFML and all its dependencies.
As a short summary you can think of static libraries like an archive of object files. These object files will directly be linking into your application, like you link your own source file object files. As such, the SFML static libraries only contain object files of SFML itself and not of other libraries as well.
Troubleshooting
If nothing seems to help, then you should enable verbose compiler & linker output, that we you see exactly which commands are invoked and one can quickly spot the missing statements.

Is it possible that run the opencv project in linux which didn't install opencv

Now I have a opencv project which was build in Linux platform, and of course it can run successfully.
I want to share the execution file of the project to other person(like boss), and other person's computer didn't install opencv
Is it possible to modified the makefile file to let the other person's computer run the project without installing opencv library?
You have to link to static OpenCV libraries. This way they are bundled with your executable, so the target system doesn't have to have shared libraries installed.
I've successfully built my executable with RPATH=$ORIGIN, which mean that I can put the openCV libraries in the same directory as the executable. This means they don't clash with existing openCV installations (or lack thereof)
When you run the executable, you will need the libraries to process the image. So, those libraries must be present for the processing purpose either by providing them in your system or by linking them to your executable itself.

How to deploy boost library?

I have used Boost library (particularly, Boost filesystem) for my project in Visual Studio C++ (9.0 version). This Boost library is installed in C drive. My project is already finished, therefore, I have corresponding Debug and Release.
Now, I want to include particular DLLs of Boost filesystem to Debug and Release, so my first question is which DLLs do I need to copy? It shows many DLLs for filesystem. Ones which I tried are "boost_filesystem-vc90-mt-1_40.dll" and "boost_filesystem-vc90-mt-gd-1_40.dll". Since, I got an idea from the "vc90", I think it means for Visual Studio 9.0?
Second question, even if I don't include these Boost filesystem DLLs to Debug or Release, my EXE file of the project is still working? Can anyone please explain why is this happening? I tried to check if I have Boost Library path somehow in my Environment Variables, but, unfortunately I could not find them there. Thanks a lot.
P.S.: I am a beginner in both C++ and Boost. And, another library that I am using is OpenCV, for which I already copied corresponding DLLs (core, highgui and imgproc) to Debug and Release and this one is working perfectly.
You have 2 options:
a. Deploy Boost DLLs together with your binary. Answering your question - of course if your project depends on Boost, the libraries are required at runtime, your binary will not start without them.
If you deploy Release configuration of your project, then you need boost_filesystem-vc90-mt-1_40.dll library. In general you can just see all the dependencies of your binary using Dependency Walker tool.
b. Link Boost libraries statically, in this case your binary will not have runtime dependency on Boost DLLs, so you don't have to deploy them

How to run C++ library with OpenCV on the other computer (linux)?

I wrote a small project using C++, OpenCV 2.2 and g++ in Ubuntu 11.04. I need to make a library (.so would be better), but I want it to run on the other computer, without OpenCV installed.
I've tried to build dynamic library using -shared and -fPIC flags for g++, and copied OpenCV .so libs to the working directory. Actually I need only core and feature2d, but actually it requested lot's of other libs, including highgui, which also has many dependencies.
I tried static linking, using -Wl,-Bstatic flags, but also unsuccessfully.
Did someone has the same problems? I would appreciate any kind of help.
It is possible to build OpenCV without dependencies from system libraries. To turn of all the dependencies for OpenCV 2.2 on Linux you can run cmake with following arguments:
cmake -DWITH_1394=OFF -DWITH_CUDA=OFF -DWITH_EIGEN2=OFF -DWITH_FFMPEG=OFF -DWITH_GSTREAMER=OFF -DWITH_GTK=OFF -DWITH_OPENEXR=OFF -DWITH_PVAPI=OFF -DWITH_QT=OFF -DWITH_TBB=OFF -DWITH_UNICAP=OFF -DWITH_V4L=OFF -DWITH_XINE=OFF -DUSE_IPP=OFF -DOPENCV_BUILD_3RDPARTY_LIBS=ON ..
But in this case you will not be able to use many of functions form highgui module:
video reading and writing
working with camera
all functions working with GUI (like imshow)

Instructions on compiling FFmpeg into static build (.lib files only) for use in Visual Studio?

So I found this post but it seems quite a bit old... So I wonder where to get 100% uptodate instructions on building ffmpeg under windows into static .lib files (for use in C and C++ projects). Point is to get ffmpeg as ONLY lib files not as lib+dll.
So where to get such instructions, can any one provide them?
What issues are you getting?
The following site may have what you need. It's automated builds of mingw ffmpeg static libraries for win32.
http://ffmpeg.arrozcru.org/autobuilds/
Here is a wiki link with lots of guides and other info about how to compile ffmpeg on windows. Also has links to other windows ffmpeg builds.
http://ffmpeg.arrozcru.org/wiki/index.php?title=Links