iPod can play the following video formats:
H.264
File formats: .m4v, .mp4, and .mov
Video: Up to 768 kbits/sec, 320 x 240, 30 frames per second (fps), Baseline Profile up to Level 1.3.
Audio: AAC-LC up to 160 kbits/sec, 48 Khz, and stereo audio.
MPEG-4
File formats: .m4v, .mp4, and .mov
Video: Up to 2.5 Mbits/sec, 480 x 480, 30 fps, Simple Profile.
Audio: AAC-LC up to 160 kbits/sec, 48 Khz, stereo audio.
All iPods can play those formats including the iPhone, touch and classics and all before it.
As long as it has .mp4 on the end, then that should be good to go. Try not to encode at any higher than 320x480 so you don't go wasting battery with 64 - 96Kbps MP3 or AAC audio. The lesser the codec (MP4 is better than H.264 in many regards), the better battery usage you get from one charge.
I use something called Rockpod, but I can't find that anywhere.