Let's debug this bit by bit. I am using system info widget to track cpu usage.

1) When idling on my desktop my cpu usage is between 1 and 3% mostly around 1%

2) after media player settles and I've selected the videos section the cpu usage is also between 1 and 3%

3) When pausing a video also the cpu usage is between 1-3%

Are your levels that low?