Encoding Videos for an Ipod

[emmgunn]

Hi Everybody!
I'm new to encoding videos for use on an ipod. I've been doing a lot of research on this topic and think/hope I'm down to my last few questions/problems. Currently I'm able to use mencoder to create videos that will work on my iphone and ipod (5G) when the resolution width is 640. When I scale down to 320 wide (the ipod screen resolution), with no other changes to the encoding setting, itunes won't sync to the ipod (though it will still do so for the iphone). The other unexpected result is that I use AtomicParsley to set set the iPod UUID atom in the 640 wide video so that itunes will load it to the ipod, yet AtomicParsley refuses to do so for the 320 wide video. This shouldn't be an issue since, from what I understand, it's only the 640 wide videos that need this setting, but I don't know for sure.

I'm hoping that there are some experts out there with knowledge in the nuances of encoding videos for the ipod who might have some ideas on what's going on. My head hurts from banging it on the wall. I know there are solutions like visualhub and ffmpegx, but I'm looking for the details of doing this with mencoder and specifically what in the itunes specifications is preventing a 320 wide video from being synced when the 640 wide version will. Thanks in advance for any help.

[Case]

ffmpegX uses ffmpeg instead of mencoder for iPod encodings, as the mencoder in ffmpegX sets a fixed AVC level to 5.1 (and no iPod atoms), which is unnecessary high for the movie specification and too high for the iPod (level 3.0).

I don't know where you got your mencoder from, or if you compiled it yourself, but if it doesn't allow you to set the AVC level, then you must find a way to change it after encoding or use a different encoding tool, for the iPod to accept the movie file.

[rumplestiltskin]

When you're done doing it the hard way:

MPEG Streamclip
or
ffmpegX
or
ViddyUp

[emmgunn]

Thanks for the responses. I know that their are easier ways to do it, but I'm looking to find a solution with command line tools.

I can set the AVC level to 3.0 with mencoder, so that's not a problem. Like I said, my process is working in general. In fact I just tested it and if I scale the video to a resolution width of 336, it works for both an iPod and an iPhone. So what is special about videos with a width of 320 that prevents it from sync if the exact same processing steps are done? That's the question I'm hoping to get answered.

[rumplestiltskin]

The older iPod software would do 320x240 (really, 76,800 pixels in total of any proportion as long as you stuck with the "rule of 16's"). The newer iPod software bumped that up to 640x480 (307,200 total pixels in any proportion but still using the "rule of 16's").

If 336 works but 320 doesn't, there must be something else that the conversion process is doing that is causing the problem. What are the heights of the two videos?

[emmgunn]

The original is 640x480 so the scaled versions were 320x240, and 336x256. The only thing I changed in the command line for the two scaled videos is the resolution, which is what has me stumped. I'll have to try 304x224 and see what happens.

It's not that big a deal really. I just wanted to be able to scale the video down if it's only going to be viewed on the ipod, so I suppose 335x256 will be acceptable. It was more of an academic question that is nagging at me.