The code employs the cmake tool to generate a variety of build environments. A visual studio code container is included for building using the visual studio code remote containers add in (highly recommended)
You may need to install libtiff; then,
cd build
cmake -DCMAKE_BUILD_TYPE=Release ../
make
sudo make install
Compilation depends on libtiff. A pre-compiled library with all the library features for Windows is not available; I am using this, but I think I have only the basic library.
cd build
cmake .. -G "Visual Studio 17 2022 Win64" -DCMAKE_PREFIX_PATH=<tiff library path>
cmake supports other visual studio versions. This command generates a solution in the build folder, which can be build using visual studio.
To compile from the command line, use
cmake --build . --config Release
To install either use
cmake --install . --prefix <your folder>
to install the library to your desired folder, or, if you want to install to C:\Program Files, you need a PowerShell/CMD running as administrator, and
cmake --install .
You can use the "For Linux" approach above. Alternatively, you can use the Xcode project in src/apps/apps.xcodeproj, which I use. Another approach is to use cmake to generate an xcode project, in the build folder, using
cd build
cmake ../ -G Xcode
make
sudo make install
I have not tested this in a long time, but you get the picture.
When you invoke cmake add -DOJPH_BUILD_TESTS=ON, then, for Windows
cd tests
ctest -C Release
For other platforms
cd tests
ctest
The test setup is a bit finicky, and may sometimes fail for silly reasons.
The library can be compiled to run with Node.js. Compilation needs the emscripten tools. One way of using these tools is to install them on your machine, and activate them using, assuming running on platform other than Windows,
source emsdk_env.sh
before compilation. Then, emcmake cmake .. emmake make
Compilation will generate two version of the library and executables, one with WebAssembly SIMD instructions and one without.
The library can now be compiled to javascript/wasm. For this purpose, a small wrapper file (ojph_wrapper.cpp) has been written to interface between javascript and C++; the wrapper currently supports decoding only. A small demo page demonstrating the script can be accessed here.
Compilation needs the emscripten tools. One way of using these tools is to install them on your machine, and activate them using
source emsdk_env.sh
before compilation. Alternatively, if you are a docker user, the you can launch a docker session using script provided at subprojects/js/emscripten-docker.sh; this script will download a third-party docker image that has the emscripten tools integrated in it -- Thanks to Chris for the suggesting and providing these tools.
The javascript decoder can be compiled using
cd subprojects/js/build
emcmake cmake ..
emmake make
The compilation creates libopenjph.js and libopenjph.wasm in subprojects/js/html folder; it also creates libopenjphsimd.js and libopenjphsimd.wasm. That html folder also has the demo webpage index.html and a compressed image test.j2c which the script in index.html decodes. The index.html detects if the browser supports WebAssembly SIMD instructions, and loads the correct library accordingly.
To run the demo webpage on your machine, you need a webserver running on the machine -- Due to security reasons, javascript engines running in a browser cannot access local files on the machine. You can use the emrun command, provided with the emscripten
tools, by issuing the command
emrun index.html
from inside the html folder; the default port is 6931. Alternatively, a simple python webserver can be run using
python -m http.server 8000
also from inside the html folder. Here, 8000 is the port number at which the webserver will be listening. The webpage can then be accessed by open localhost:8000 in you browser. Any browser supporting webassembly can be used to view this webpage; examples include Firefox, Chrome, Safari, and Edge, on a desktop, mobile, or tablet.
Visual Studio Code Remote Containers are now available with OpenJPH. These scripts/configuration files are provided by Chris -- Thank you Chris, and I must say I am not familiar with them.
The scripts, in the .devcontainer folder, will build a docker image that can be used with visual studio code as a development environment.
Compilation should simply work now. The simple test code I have passes when run on MacOS ARM on GitHub.
The code now employs the architecture-agnostic option OJPH_DISABLE_SIMD, which should include SIMD instructions wherever they are supported. This can be achieved with -DOJPH_DISABLE_SIMD=ON option during CMake configuration. Individual instruction sets can be disabled; see the options in the main CMakeLists.txt file.