Video Length is Wrong
 

I have a few videos that I downloaded on eMule.

To play them, I have to uncheck the box that says "Allow hardware video overlay".

But, when I play them, it only plays the first ~30 seconds of the video. Although the video stops after 30 seconds, the audio continues. Also, if I click on the video timeline, I can see the other scenes of the video.

Does anyone know what is wrong?