_________
main.qml:

...
    Sprite {
        id: mysprite
        src: "mysprite.png"
        frames: 5
        currentFrame: 0 // initial frame
    }
...

___________
Sprite.qml:

import Qt 4.7

Rectangle {
    property string src: parent ? "" : "sprite-unittest.png"
    property int frames: parent ? 1 : 7
    property int currentFrame: 0

    width: sprite_image.sourceSize.width / frames
    height: sprite_image.sourceSize.height
    color: "transparent"
    clip: true

    Image {
        id: sprite_image
        source: src
        x: -currentFrame * (sprite_image.sourceSize.width / frames)
    }
}