Also, here are the specs from Apple:
Video formats supported: H.264 video, up to 1.5 Mbps, 640 by 480
pixels, 30 frames per sec., Low-Complexity version of the H.264
Baseline Profile with AAC-LC audio up to 160 Kbps, 48 kHz, stereo audio
in .m4v, .mp4, and .mov file formats; H.264 video, up to 768 Kbps, 320
by 240 pixels, 30 frames per sec., Baseline Profile up to Level 1.3
with AAC-LC audio up to 160 Kbps, 48 kHz, stereo audio in .m4v, .mp4,
and .mov file formats; MPEG-4 video, up to 2.5 Mbps, 640 by 480 pixels,
30 frames per sec., Simple Profile with AAC-LC audio up to 160 Kbps, 48
kHz, stereo audio in .m4v, .mp4, and .mov file formats