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QGLWidget and JPEG

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  • D Offline
    D Offline
    debian
    wrote on last edited by
    #1

    Hello!
    I need to view JPEG from IP-camera. My code:
    @QByteArray jpg;
    GLuint texture;
    QSize frame_resolution;@
    initializeGL()
    @qglClearColor(Qt::black);@
    resizeGL(int width, int height)
    @texture = bindTexture(QImage::fromData(jpg));@
    paintGL()
    @drawTexture(QRectF(-frame_resolution.width()/2,
    -frame_resolution.height()/2,
    frame_resolution.width(),
    frame_resolution.height()),
    texture);@
    I successfully get JPEG from camera, but I see only grey rectangle.

    Ok, I try check this function with local image, but I get strange result:
    @texture = bindTexture(QImage("/tmp/test.jpg"));@
    I view brown rectangle.
    @texture = bindTexture(QString("/tmp/test.jpg"));@
    I view white rectangle.

    My question - how can I see JPEG with QGLWidget and OpenGL.
    Thank you and excuse me for my bad english.

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    • M Offline
      M Offline
      mlong
      wrote on last edited by
      #2

      See "QGLWidget::convertToGLFormat()":http://doc.qt.nokia.com/4.7/qglwidget.html#convertToGLFormat.

      Software Engineer
      My views and opinions do not necessarily reflect those of anyone -- living or dead, real or fictional -- in this universe or any other similar multiverse node. Void where prohibited. Your mileage may vary. Caveat emptor.

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      0
      • D Offline
        D Offline
        debian
        wrote on last edited by
        #3

        bq. QImage QGLWidget::convertToGLFormat ( const QImage & img ) [static]
        Converts the image img into the unnamed format expected by OpenGL functions such as glTexImage2D(). The returned image is not usable as a QImage, but QImage::width(), QImage::height() and QImage::bits() may be used with OpenGL. The GL format used is GL_RGBA.

        Why if I don't use glTexImage2D and etc or bindTexture don't convert image?

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        • M Offline
          M Offline
          mlong
          wrote on last edited by
          #4

          Are you calling

          @
          glEnable(GL_TEXTURE_2D);
          @

          in your code?

          Software Engineer
          My views and opinions do not necessarily reflect those of anyone -- living or dead, real or fictional -- in this universe or any other similar multiverse node. Void where prohibited. Your mileage may vary. Caveat emptor.

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          0
          • D Offline
            D Offline
            debian
            wrote on last edited by
            #5

            I post all code. I think what I don't need mixture OpenGL and Qt functions.

            1 Reply Last reply
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