Converting Videos for iPod, Take 2 (Twelve Black Code Monkeys). My buddy at Twelve Black Monkeys went through the hard work of encoding in different formats and then figuring out what the tradeoffs are.
The basic points from his spreadsheet are that basically recommends H.264 at a CBR (constant bit rate) if you are only doing viewing on the iPod. It is quite a bit (50% smaller) and he also points out that using 1 pass is fine, he at least didn’t see any benefit. They also have a variable bit rate mode called (FQ VBR or Fixed quality Variable Bit Rate). His measurement shows that a 384Kbps CBR is equivalent in length to FQ VBR at a Qscale (Quality Scale) of 30. While a QScale of 20 is equivalent to 768Kpbs, 768K is the maximum bit rate for the iPod using H.264.
I’ve actually used Q20 and found that there are times when the bit rate exceeds 768Kbps and it won’t play. Q30 sometimes has the same problem, so unfortunately, you pretty much want to go to a CBR.
On MPEG 4, you have to get up to 2.5Mbps to get the same quality, H.264 is a better codec. That makes sense, it was developed later and is new with more advanced encoding.
Net, net, if you have time, I’d recommend encoding at H.264 768Kbps 2 pass 320×240 for most reliable if bigger encoding. If you have time, the theory is that Q20 should be better but at least for this test, it didn’t show it and there is some chance that it won’t playback at all since complicated scenes will not play in the iPod.
