Question

I have a windows media player COM in my Windows Form project that plays and opens videos admirably. However, I would like to be able to grab the first frame of the loaded video so my program users can preview the video (and, ideally, recognize one video from another).

How can I update the frame displayed by the windows media player object?

I have tried using the following code at the end of my openFileDialog event response:

private void openFileDialog1_FileOk(object sender, CancelEventArgs e)
{
    Text = openFileDialog1.SafeFileName + " - MPlayer 2.0";
    //mediaPlayer1.openPlayer(openFileDialog1.FileName);
    mediaPlayer1.URL = openFileDialog1.FileName;
    //hopefully, this will load the first frame.
    mediaPlayer1.Ctlcontrols.play();
    mediaPlayer1.Ctlcontrols.pause();           
}

However, when I run this, the pause command gets ignored (Auto-play for video loading is turned off, so the video won’t start playing without calling .play(), above). If I had to guess, I’d say that this is because of some threading operation that calls play, moves on to call pause, calls pause, and then, finally, the play resolves, and the video starts – but because the .pause resolved before the .play, the net effect is the .pause is ultimately unheeded.

Firstly, is there a way other than .play(); .pause(); to snag a preview image of the video for the AxWindowsMediaPlayer object? If not, how can I make sure that my .pause() doesn’t get ignored?

(I know that .play(); .pause(); works in the general case, because I tested with a separate button that invoked those two methods after the video finished loading, and it worked as expected)

Answer 1

While the Windows Media Player Com might not officially support a feature like this, its quite easy to ‘fake’ this. If you use a CtlControls2, you have access to the built-in “step(1)” function, which proceeds exactly one frame.

I’ve discovered that if you call step(1) after calling pause(), searching on the trackbar will also update the video.

It’s not pretty, but it works!