Question

我目前正在将一些代码从Matlab移植到Octave。 Matlab代码的一些功能使用包含一些mex文件的Piotr的计算机视觉Matlab工具箱（here）。在Matlab中，一切都像魅力一样，但当我用Octave运行我的代码时，它会抛出这个错误：

error: 'imResampleMex' undefined near line 50 column 5

然而，工具箱中的所有内部路径都应该是好的。我发现Matlab和Octave处理mex文件的方式不同，并尝试在Octave中构建一个来自C ++函数的mex文件，如下所示：

mkoctfile --mex imResampleMex.cpp

它失败并抛出以下与C ++包装函数相关的错误消息：

In file included from imResampleMex.cpp:6:0:
wrappers.hpp:21:24: error: 'wrCalloc' declared as an 'inline' variable
 inline void* wrCalloc( size_t num, size_t size ) { return calloc(num,size);
                        ^
wrappers.hpp:21:24: error: 'size_t' was not declared in this scope
wrappers.hpp:21:36: error: 'size_t' was not declared in this scope
 inline void* wrCalloc( size_t num, size_t size ) { return calloc(num,size);
                                    ^
wrappers.hpp:21:48: error: expression list treated as compound expression in initializer [-fpermissive]
 inline void* wrCalloc( size_t num, size_t size ) { return calloc(num,size);
                                                ^
wrappers.hpp:21:50: error: expected ',' or ';' before '{' token
 inline void* wrCalloc( size_t num, size_t size ) { return calloc(num,size);
                                                  ^
wrappers.hpp:22:24: error: 'wrMalloc' declared as an 'inline' variable
 inline void* wrMalloc( size_t size ) { return malloc(size); }
                        ^
wrappers.hpp:22:24: error: 'size_t' was not declared in this scope
wrappers.hpp:22:38: error: expected ',' or ';' before '{' token
 inline void* wrMalloc( size_t size ) { return malloc(size); }
                                      ^
wrappers.hpp: In function 'void wrFree(void*)':
wrappers.hpp:23:44: error: 'free' was not declared in this scope
 inline void wrFree( void * ptr ) { free(ptr); }
                                            ^
wrappers.hpp: At global scope:
wrappers.hpp:28:17: error: 'size_t' was not declared in this scope
 void* alMalloc( size_t size, int alignment ) {
                 ^
wrappers.hpp:28:30: error: expected primary-expression before 'int'
 void* alMalloc( size_t size, int alignment ) {
                              ^
wrappers.hpp:28:44: error: expression list treated as compound expression in initializer [-fpermissive]
 void* alMalloc( size_t size, int alignment ) {
                                            ^
wrappers.hpp:28:46: error: expected ',' or ';' before '{' token
 void* alMalloc( size_t size, int alignment ) {
                                              ^
imResampleMex.cpp: In function 'void resampleCoef(int, int, int&, int*&, int*&, T*&, int*, int)':
imResampleMex.cpp:21:39: error: 'alMalloc' cannot be used as a function
   wts = (T*)alMalloc(nMax*sizeof(T),16);
                                       ^
imResampleMex.cpp:22:43: error: 'alMalloc' cannot be used as a function
   yas = (int*)alMalloc(nMax*sizeof(int),16);
                                           ^
imResampleMex.cpp:23:43: error: 'alMalloc' cannot be used as a function
   ybs = (int*)alMalloc(nMax*sizeof(int),16);
                                           ^
imResampleMex.cpp: In function 'void resample(T*, T*, int, int, int, int, int, T)':
imResampleMex.cpp:48:43: error: 'alMalloc' cannot be used as a function
   T *C = (T*) alMalloc((ha+4)*sizeof(T),16); for(y=ha; y<ha+4; y++) C[y]=0;
                                           ^
warning: mkoctfile: building exited with failure status

wrappers.hpp文件如下所示：

#ifndef _WRAPPERS_HPP_
#define _WRAPPERS_HPP_
#ifdef MATLAB_MEX_FILE

// wrapper functions if compiling from Matlab
#include "mex.h"
inline void wrError(const char *errormsg) { mexErrMsgTxt(errormsg); }
inline void* wrCalloc( size_t num, size_t size ) { return mxCalloc(num,size); }
inline void* wrMalloc( size_t size ) { return mxMalloc(size); }
inline void wrFree( void * ptr ) { mxFree(ptr); }

#else

// wrapper functions if compiling from C/C++
inline void wrError(const char *errormsg) { throw errormsg; }
inline void* wrCalloc( size_t num, size_t size ) { return calloc(num,size); }
inline void* wrMalloc( size_t size ) { return malloc(size); }
inline void wrFree( void * ptr ) { free(ptr); }

#endif

// platform independent aligned memory allocation (see also alFree)
void* alMalloc( size_t size, int alignment ) {
  const size_t pSize = sizeof(void*), a = alignment-1;
  void *raw = wrMalloc(size + a + pSize);
  void *aligned = (void*) (((size_t) raw + pSize + a) & ~a);
  *(void**) ((size_t) aligned-pSize) = raw;
  return aligned;
}

// platform independent alignned memory de-allocation (see also alMalloc)
void alFree(void* aligned) {
  void* raw = *(void**)((char*)aligned-sizeof(void*));
  wrFree(raw);
}

#endif

我想我需要修改这个文件，但是我对C ++和mex文件的知识几乎不存在，我正在努力想办法摆脱这一堆错误。我甚至不知道我是否朝着正确的方向前进......欢迎任何帮助！

修改1：

我修改了我的wrappers.hpp文件，添加了#include <stdlib.h>。现在创建了一个mex文件。但是，在运行调用该文件的函数时，我现在收到以下错误：

error: failed to install .mex file function 'imResampleMex'
error: called from
    imResample at line 50 column 4

Answer 1

以下是我用来解决从Piotr的计算机视觉Matlab Toolbox for Octave创建mex文件的问题的步骤（仅涉及文件夹df2[['b','c']].replace(-9223372036854775808, -1, inplace=True)的cpp文件）。

工具箱附带的原始mex文件是为Matlab构建的，不适用于Octave。从Octave构建它们时，会调用文件channels。必须通过在文件开头添加以下两行来修改此文件：wrappers.hpp和#include <stdlib.h>。

要构建mex文件，请在Octave提示符类型中（当位于cpp文件的目录中时）：

#include "mex.h"

这样就创建了Octave兼容的mex文件。

编辑23/05/2017 - 在收到生成这些文件时遇到问题的人的更多问题后，我在Github上发布了生成的文件：https://github.com/Eskapp/Piotr_vision_extrafiles_Octave。随意使用它们。您需要手动将它们添加到Computer Vision工具箱中。

使用Octave构建Mex文件（包装器问题）

1 个答案: