Invest in the DVCproHD codec. There are a few sites that offer it for sale, one being:
http://www.rastervector.com/
or try downloading the Avid codec pack and use either DV100 or DNxHD. Otherwise you can use the QT Animation codec. Like Mr. T said, H.264 is for web and for low-res QT files to send to client for work-in-progress approvals...