The videos are 1280x720, which is too big for an (original) iPod touch or iPhone 3/3G/3GS. (They will work fine with the new iPod touch and the iPad though.)
For playback on an original iPod touch, you need to transcode to something smaller. (You may want to transcode even for a new iPod touch to save on storage.)
The original iPod touch has a screen resolution of 480x320, as does the iPhone 3/3G/3GS. The new ones have 960x640.
Popular options are to transcode for
- iPod touch at 480x272
- iPod classic at 320x176
- iPhone 4 and new iPod touch at 960x544
- iPad at 1024x576
- iPod classic at 640x352
- Universal at 720x400
Except for the last two, each of these takes advantage of the maximum resolution of the respective device.
Personally, I like the 320-wide option for everything, simply because the videos are reference material: the low video quality doesn't matter as long as I can recognise what's going on, and the 320-wide option results in files that are very small.
The universal option is useful if you want to be able to view the video on more than one portable device with different native resolutions because that resolution works for all of them (including an iPod classic). At the same time, at 720 wide, you can connect an AV cable to your device and view the video in very nice quality on a large screen. This gives you the best of both worlds, at the cost of larger file size.
The 640 option does the same thing, allowing you to view the video on both your mobile device and to display it on a larger screen at fairly decent quality, while reducing file size a bit more than the 720 option.
For a 2-minute video, the approximate sizes are:
- 320: 3.2MB
- 480: 4.5MB
- 640: 6.1MB
- 720: 7.1MB
- 960: 11.0MB
- 1024: 12.1MB
The exact sizes vary on how aggressively you compress the video, so the above is only a rough guide.
Cheers,
Michi.