webarkit / opencv-em

A simple utility script to build OpenCV static libs with Emscripten

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opencv-em's Issues

project wasm-ar fails to build

@EdwardLu2018 I created a build from the script with the libs, includes and opencv.js files. It use now the python command:

opencv-em/build.sh

Line 25 in eb3d872

python ./platforms/js/build_js.py ../build_wasm --build_wasm

as i used already (and that was fine before) but with your latest changes i receive this error:

emmake make
make: make
Scanning dependencies of target wasm_ar
[ 50%] Building CXX object CMakeFiles/wasm_ar.dir/src/wasm_ar.cpp.o
[100%] Linking CXX executable wasm_ar.js
error: undefined symbol: _ZN2cv3MatC1ERKS0_ (referenced by top-level compiled C/C++ code)
warning: Link with `-s LLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-s ERROR_ON_UNDEFINED_SYMBOLS=0`
warning: __ZN2cv3MatC1ERKS0_ may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
error: undefined symbol: _ZN2cv3MatC1EiiiPvm (referenced by top-level compiled C/C++ code)
warning: __ZN2cv3MatC1EiiiPvm may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
error: undefined symbol: _ZN2cv3MatC1Ev (referenced by top-level compiled C/C++ code)
warning: __ZN2cv3MatC1Ev may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
error: undefined symbol: _ZN2cv3MatD1Ev (referenced by top-level compiled C/C++ code)
warning: __ZN2cv3MatD1Ev may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
error: undefined symbol: _ZNK2cv3Mat5cloneEv (referenced by top-level compiled C/C++ code)
warning: __ZNK2cv3Mat5cloneEv may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
error: undefined symbol: _ZNK2cv3Mat5emptyEv (referenced by top-level compiled C/C++ code)
warning: __ZNK2cv3Mat5emptyEv may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: '/home/walter/emsdk/node/12.18.1_64bit/bin/node /home/walter/emsdk/upstream/emscripten/src/compiler.js /tmp/tmpof609eqg.txt' failed (1)
make[2]: *** [CMakeFiles/wasm_ar.dir/build.make:96: wasm_ar.js] Errore 1
make[1]: *** [CMakeFiles/Makefile2:76: CMakeFiles/wasm_ar.dir/all] Errore 2
make: *** [Makefile:84: all] Errore 2

i include the package in zip format
opencv-em-4.5.0-beta.zip
If you can test, i will appreciate it.

Build with highgui and videoio modules

I'm trying to build with highgui and videoio modules, in this branch https://github.com/webarkit/opencv-em/tree/with-highgui. But the process stops at videoio compilation, see log:

emcc:WARNING: --llvm-lto ignored when using llvm backend
../modules/videoio/src/backend_plugin.cpp:76:30: warning: unused parameter 'h' [-Wunused-parameter]
void* getSymbol_(LibHandle_t h, const char* symbolName)
                             ^
../modules/videoio/src/backend_plugin.cpp:76:45: warning: unused parameter 'symbolName' [-Wunused-parameter]
void* getSymbol_(LibHandle_t h, const char* symbolName)
                                            ^
../modules/videoio/src/backend_plugin.cpp:83:1: error: non-void function does not return a value [-Werror,-Wreturn-type]
}
^
../modules/videoio/src/backend_plugin.cpp:86:50: warning: unused parameter 'filename' [-Wunused-parameter]
LibHandle_t libraryLoad_(const FileSystemPath_t& filename)
                                                 ^
../modules/videoio/src/backend_plugin.cpp:97:1: error: non-void function does not return a value [-Werror,-Wreturn-type]
}
^
../modules/videoio/src/backend_plugin.cpp:100:34: warning: unused parameter 'h' [-Wunused-parameter]
void libraryRelease_(LibHandle_t h)
                                 ^
4 warnings and 2 errors generated.

@ThorstenBux it was possible with opencv 4.1 but maybe is not possible with 4.5.0?

example and documentation

can we an example and documentation on how-to use this? :)

Build python fails

If you run the ./build python script after the ./build cmake the python script will fail. We should remove the build_wasm directory (inside opencv folder!) before running any command in this case cmake will be restarted correctly. It will be also useful to add another command to build all the entries (python and cmake version)