Quality of Rendered Output

Hi,

I'm experimenting rendering out project I've just finished using H.264 and the 'best' output settings. I'm using 32 bpc in terms of colour and a resolution of 1920x1080.

However, the output doesn't seem that great - a little noisy and grainy. Is there is trick to improve it or is it down to the video codec? A PSD image sequence seems to render best etc...

Many thanks gentlemen.

Cheers.

Jas