I stream movies on my X box 360 but most of the movies are .mp4 so I end up converting them to .avi so they can stream. On occasion I find .avi movies. But I'm wondering which is better because the size is larger only when converting to .avi. Is the picture better or something once I convert? .mp4 to .avi yields usually a 3-4GB movie When just downloading an .avi files it's usually around 700 MB.
No the picture is not better. The likely reason it's bigger is that you didn't set the compression properly - for example, the codec bit-rate.
The XBOX 360 supports .mp4, depending on what audio/video codecs are used;are you certain you need to do the conversion o AVI: http://support.xbox.com/support/en/us/nxe/GamesandMedia/Movies/VideoFAQ/ViewVideoPlaybackFAQ.aspx
Yeah anytime I've tried to play a .mp4 movie I get an error. And I have the media update already. I even changed the file extension to .avi and that doesn't work. I get this error "Can't play this content because it may not be supported..." Status code: 69-C00D36C4
I forgot to note changing the file extension does work on Vista, but not on the X box 360. So not sure what the deal is.