Sudden Degrade in Quicktime Record Quality

So I use Quicktime X to my screen. At first it was fine. Thequality was perfect etc.

Now I have not changed my settings at all. I don't even know how to, but suddenly quicktime provides very poor quality recorings. The text looks very blurred, the colours look far too bright and have some sort of purple haze around them, and it just generally looks terrible.

Anyone know how to fix? I don't remember changing anything.