for a school project I need to connect a Intel Realsense (3D camera) with Python to use it with RoboDK and OpenCV. I'm doing this with MVS 2019. With superfastcode2 (C++) and RealsenseDistanceV3 (Python) set to 64-bit.
This tutorial I followed for creating a C++ extension and that works good.
Now I'm including the <librealsense2\rs.hpp> into the module.cpp code and everything compiles and works well. However, only in release mode. In debug mode I get these errors while compiling:
Error LNK2019 unresolved external symbol __imp__invalid_parameter referenced in function "void * __cdecl std::_Allocate_manually_vector_aligned<struct std::_Default_allocate_traits>(unsigned __int64)" (??$_Allocate_manually_vector_aligned@U_Default_allocate_traits@std@@@std@@YAPEAX_K@Z) superfastcode2 C:\Users\Gebruiker\source\repos\RealsenseDistanceV3\superfastcode2\module.obj
Error LNK2019 unresolved external symbol __imp__CrtDbgReport referenced in function "void * __cdecl std::_Allocate_manually_vector_aligned<struct std::_Default_allocate_traits>(unsigned __int64)" (??$_Allocate_manually_vector_aligned@U_Default_allocate_traits@std@@@std@@YAPEAX_K@Z) superfastcode2 C:\Users\Gebruiker\source\repos\RealsenseDistanceV3\superfastcode2\module.obj
When using a function (rs2::pipeline p;) from the Realsense library in the C++ code, the following error occurs. DLL load failed while importing superfastcode2: Kan opgegeven module niet vinden (English: cannot find module).
That is logical because when looking at the superfastcode2.log it says:
Creating library C:\Users\Gebruiker\source\repos\RealsenseDistanceV3\Release\superfastcode2.lib and object C:\Users\Gebruiker\source\repos\RealsenseDistanceV3\Release\superfastcode2.exp
module.obj : error LNK2001: unresolved external symbol __imp__PyFloat_AsDouble
module.obj : error LNK2001: unresolved external symbol __imp__PyFloat_FromDouble
module.obj : error LNK2001: unresolved external symbol __imp__PyModule_Create2
C:\Users\Gebruiker\source\repos\RealsenseDistanceV3\Release\superfastcode2.pyd : fatal error LNK1120: 3 unresolved
Module.cpp (from superfastcode2):
#include <Python.h>
#include <Windows.h>
#include <cmath>
#include <librealsense2\rs.hpp> // Include RealSense Cross Platform API
#include <iostream> // for cout
const double e = 2.7182818284590452353602874713527;
double sinh_impl(double x) {
return (1 - pow(e, (-2 * x))) / (2 * pow(e, -x));
}
double cosh_impl(double x) {
return (1 + pow(e, (-2 * x))) / (2 * pow(e, -x));
}
double askRealsenseDistance()
{
return 5.25;
}
void connectRealsense()
{
rs2::pipeline p;
}
PyObject* tanh_impl(PyObject*, PyObject* o) {
double x = PyFloat_AsDouble(o);
double tanh_x = sinh_impl(x) / cosh_impl(x);
return PyFloat_FromDouble(tanh_x);
}
PyObject* askRealsenseDistance_impl(PyObject*, PyObject* o) {
//double distance = askRealsenseDistance();
double distance = PyFloat_AsDouble(o)/100;
connectRealsense();
return PyFloat_FromDouble(distance);
}
static PyMethodDef superfastcode2_methods[] = {
// The first property is the name exposed to Python, fast_tanh, the second is the C++
// function name that contains the implementation.
{ "fast_tanh", (PyCFunction)tanh_impl, METH_O, nullptr },
{ "askRealsenseDistance_py", (PyCFunction)askRealsenseDistance_impl, METH_O, nullptr },
// Terminate the array with an object containing nulls.
{ nullptr, nullptr, 0, nullptr }
};
static PyModuleDef superfastcode2_module = {
PyModuleDef_HEAD_INIT,
"superfastcode2", // Module name to use with Python import statements
"Provides some functions, but faster", // Module description
0,
superfastcode2_methods // Structure that defines the methods of the module
};
PyMODINIT_FUNC PyInit_superfastcode2() {
return PyModule_Create(&superfastcode2_module);
}
And RealsenseDitanceV3.py (from RealsenseDistanceV3):
from itertools import islice
from random import random
from time import perf_counter
from superfastcode2 import fast_tanh
from superfastcode2 import askRealsenseDistance_py
COUNT = 500000 # Change this value depending on the speed of your computer
DATA = list(islice(iter(lambda: (random() - 0.5) * 3.0, None), COUNT))
e = 2.7182818284590452353602874713527
def sinh(x):
return (1 - (e ** (-2 * x))) / (2 * (e ** -x))
def cosh(x):
return (1 + (e ** (-2 * x))) / (2 * (e ** -x))
def tanh(x):
tanh_x = sinh(x) / cosh(x)
return tanh_x
def test(fn, name):
start = perf_counter()
result = fn(DATA)
duration = perf_counter() - start
print('{} took {:.3f} seconds\n\n'.format(name, duration))
for d in result:
assert -1 <= d <= 1, " incorrect values"
#if __name__ == "__main__":
#print('Running benchmarks with COUNT = {}'.format(COUNT))
#test(lambda d: [tanh(x) for x in d], '[tanh(x) for x in d] (Python implementation)')
#test(lambda d: [fast_tanh(x) for x in d], '[fast_tanh(x) for x in d] (CPython C++ extension)')
number = 8050
print('send: {} to cpp which divides it by 100'.format(number))
output = askRealsenseDistance_py(number)
print('received from cpp: {}'.format(output))
For clarification, if the line rs2::pipeline p; or if the line connectRealsense(); is removed from module.cpp, everything works fine. Somehow, I think the Realsense C++ functions are not recognised (or something) by the Python.h (CPython) library.
Hope you have some suggestions, thanks in advance!
