Today I downloaded one video file(.wmv) from the internet and played it on my computer, which is one Windows system.
Soon I found there is no sound in movie. I guess this kind of file may not be played well in my shooter player and changed to play it with windows media player. One popup appeared:
Next, I checked its properties after I put it into the media library:
Finally I know where the codec information of one video file can be found. But I have no idea how to fix this. Maybe the guy who made this movie knows.