cv::Mat中的地址错误

Bad address in cv::Mat

本文关键字：地址 错误 Mat cv      更新时间：2023-10-16

我正在制作一个使用 opencv 和 zeromq 的C++应用程序。在尝试通过 zmq tcp 套接字发送 cv：：Mat 对象 (CV_8UC3( 时，我遇到了一些问题。

下面是更新的代码示例：

#include <iostream>
#include <zmq.hpp>
#include <pthread.h>
#include <opencv/cv.h>
#include <opencv/highgui.h>
using namespace std;
int main()
{
    zmq::context_t ctx( 1 );
    zmq::socket_t mysocket( ctx, ZMQ_PUSH );
    mysocket.bind( "tcp://lo:4050" );
    cv::VideoCapture capture( CV_CAP_ANY );
    capture.set( CV_CAP_PROP_FRAME_WIDTH, 640 );
    capture.set( CV_CAP_PROP_FRAME_HEIGHT, 480 );
    cv::Mat3b frame;
    capture >> frame; //First one is usually blank
    capture >> frame;
    capture >> frame;
    cv::Mat3b clonedFrame( 480, 640, CV_8UC3 );
    frame.copyTo( clonedFrame );
    cout << "Original:" << endl
         << "Address of data:t" << &frame.data << endl
         << "Size:ttt" << frame.total() * frame.channels() << endl << endl;
    cout << "Cloned:" << endl
         << "Address of data:t" << &clonedFrame.data << endl
         << "Size:ttt" << clonedFrame.total() * clonedFrame.channels() << endl << endl;
    cout << "Gap between data:t" << &clonedFrame.data - &frame.data << endl;
    unsigned int frameSize = frame.total() * frame.channels();
    zmq::message_t frameMsg( frame.data, frameSize, NULL, NULL );
    zmq::message_t clonedFrameMsg( clonedFrame.data, frameSize, NULL, NULL );
    cv::imshow( "original", frame );
    cv::imshow( "cloned", clonedFrame );

    cvWaitKey( 0 );
    if( frame.isContinuous() )
    {
        cout << "Sending original frame" << endl;
        mysocket.send( frameMsg, 0 ); //This works
        cout << "done..." << endl;
    }
    cvWaitKey( 0 );
    if( clonedFrame.isContinuous() )
    {
        cout << "Sending cloned frame" << endl;
        mysocket.send( clonedFrameMsg, 0 ); //This fails
        cout << "done..." << endl;
    }
    return EXIT_SUCCESS;
}

后者 send(( 使 zmq 失败一些断言。输出： 

Original:
Address of data:    0xbfdca480
Size:           921600
Cloned:
Address of data:    0xbfdca4b8
Size:           921600
Gap between data:   14
Sending original frame
done...
Sending cloned frame
Bad address
done...
nbytes != -1 (tcp_socket.cpp:203)

为什么 clone(( 会弄乱指针，我该如何解决这个问题？

任何帮助，不胜感激。

编辑 2012-05-25：更新了代码示例。我可以通过向消息构造函数提供以下指针之一来发送原始帧：frame.ptr((，frame.data，frame.datastart，frame.at((。它们都适用于原始版本，但不适用于构造函数。如您所见，两个数据指针之间的地址空间很小。它不应该至少是框架大小吗？

//John

好的...所以我最终制作了自己的复制功能

它看起来像这样：

struct frameData_t
{
    unsigned char *data;
    size_t size;
};
struct frameData_t *copyMatData( cv::Mat3b &indata )
{
    struct frameData_t *ret = new struct frameData_t;
    ret->size = indata.total() * indata.channels();
    ret->data = new unsigned char[ret->size];
    int datapos = 0;
    for( int channel = 0; channel < indata.channels(); channel++ )
    {
        for( int row = 0; row < indata.rows; row++ )
        {
            const cv::Vec3b *srcrow = indata[row];
            for( int col = 0; col < indata.cols; col++, datapos++ )
            {
                ret->data[datapos] = srcrow[col][channel];
            }
        }
    }
    return ret;
}

我像这样使用它：

struct frameData_t *clonedFrame = copyMatData( frame );
zmq::message_t frameMsg( frame.data, frameSize, NULL, NULL );
mysocket.send( clonedFrameMsg, 0 );

如果有人知道更好的方法，请告诉我。

//John

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