Webcam Video Capture

[bajoelkid12]

Hello everybody..

I'm new in Qt, and new in OpenCV..

I want to make a program to capture a video from USB webcam, then save it to the server..

For now, i have download a source code that use Qt and OpenCV to view images from webcam.. i download it here, http://qt-apps.org/content/show.php/...?content=89995

do you have any suggestion, how should i modifiy this source code, so that it can record the video, and save it ?

i really appreciate your help.. thanks before

P.S : sorry for my bad english

[stampede]

do you have any suggestion

Yes, read OpenCV documentation, for example:
CvVideoWriter
CvWriteFrame
Post again if you have specific problems with your code.

[bajoelkid12]

thank you for your respond stampede.. i'm now working on how to integrate OpenCV video writing and reading function in Qt framework.. . maybe you have some advice ?

[stampede]

You mean you are having some problems with using OpenCv in your code, or just thinking how to do that nicely ? If its the latter, then I'd create a wrapper class(es) with nice interface, which will hide all the OpenCV stuff from client classes. What I mean is something like:

class VideoReader : public QObject{
Q_OBJECT
public:
    VideoReader( const QString& file, QObject * parent = NULL );
    ... /// information
    int frameCount() const;
    QSize frameSize() const;
    ... // other methods, like video fps etc
    /// capture methods
    QImage getFrame( int frameNumber ) const; // or return QPixmap, or your own Image class
...
};

class VideoReader : public QObject{
Q_OBJECT
public:
    VideoReader( const QString& file, QObject * parent = NULL );
    ... /// information
    int frameCount() const;
    QSize frameSize() const;
    ... // other methods, like video fps etc
    /// capture methods
    QImage getFrame( int frameNumber ) const; // or return QPixmap, or your own Image class
...
};

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It's always better to have class with good interface, than C-style OpenCv api calls all over the code. I think you get the idea.

[bajoelkid12]

actually yes.. i have some problems with using OpenCV in my code.. this is what i've done so far..

mycamerawindow.cpp

#include "MyCameraWindow.h"
 
MyCameraWindow::MyCameraWindow(CvCapture *cam, QWidget *parent) : QWidget(parent) {
    camera = cam;
    QVBoxLayout *layout = new QVBoxLayout;
    cvwidget = new QOpenCVWidget(this);
    layout->addWidget(cvwidget);
    setLayout(layout);
    resize(500, 400);
 
    startTimer(100);  // 0.1-second timer
 }
 
void MyCameraWindow::timerEvent(QTimerEvent*) {
    IplImage *image=cvQueryFrame(camera);
    cvwidget->putImage(image);
}

#include "MyCameraWindow.h"

MyCameraWindow::MyCameraWindow(CvCapture *cam, QWidget *parent) : QWidget(parent) {
    camera = cam;
    QVBoxLayout *layout = new QVBoxLayout;
    cvwidget = new QOpenCVWidget(this);
    layout->addWidget(cvwidget);
    setLayout(layout);
    resize(500, 400);

    startTimer(100);  // 0.1-second timer
 }

void MyCameraWindow::timerEvent(QTimerEvent*) {
    IplImage *image=cvQueryFrame(camera);
    cvwidget->putImage(image);
}

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i get this code from http://qt-apps.org/content/show.php/...?content=89995

btw thank you for the algorithm, now i'll try to implement it to my code.. but if you don't mind, may i send my project file to you ?

[stampede]

actually yes.. i have some problems with using OpenCV in my code..

What kind of problems ? Image is not displayed ? Displayed but incorrect ? Other ?

but if you don't mind, may i send my project file to you ?

What for ? I think you can get all the help you need by asking specific questions on this forum.

[Thà nh Viên Mới]

actually yes.. i have some problems with using OpenCV in my code.. this is what i've done so far..

mycamerawindow.cpp

#include "MyCameraWindow.h"
 
MyCameraWindow::MyCameraWindow(CvCapture *cam, QWidget *parent) : QWidget(parent) {
    camera = cam;
    QVBoxLayout *layout = new QVBoxLayout;
    cvwidget = new QOpenCVWidget(this);
    layout->addWidget(cvwidget);
    setLayout(layout);
    resize(500, 400);
 
    startTimer(100);  // 0.1-second timer
 }
 
void MyCameraWindow::timerEvent(QTimerEvent*) {
    IplImage *image=cvQueryFrame(camera);
    cvwidget->putImage(image);
}

#include "MyCameraWindow.h"

MyCameraWindow::MyCameraWindow(CvCapture *cam, QWidget *parent) : QWidget(parent) {
    camera = cam;
    QVBoxLayout *layout = new QVBoxLayout;
    cvwidget = new QOpenCVWidget(this);
    layout->addWidget(cvwidget);
    setLayout(layout);
    resize(500, 400);

    startTimer(100);  // 0.1-second timer
 }

void MyCameraWindow::timerEvent(QTimerEvent*) {
    IplImage *image=cvQueryFrame(camera);
    cvwidget->putImage(image);
}

To copy to clipboard, switch view to plain text mode 

i get this code from http://qt-apps.org/content/show.php/...?content=89995

btw thank you for the algorithm, now i'll try to implement it to my code.. but if you don't mind, may i send my project file to you ?

if you use your code, you cant record with audio, how to record video with audio use OpenCV ???