H.264 vs MPEG-4 file size

Question

Apple's docs seem to indicate these are different, e.g.

http://developer.apple.com/library/ios/#documentation/Miscellaneous/Conceptual/iPhoneOSTechOverview/MediaLayer/MediaLayer.html

But which produces smaller file sizes and which will produce better video quality for a fixed video size?

Answer 1

In general H.264 will be better than MPEG4.This is not true in all conditions and depends on toolsets being employed but if you are encoding for iOS with standard encoding requirements and conditions h.264 is much better.