Hi there, I've done some extensive experimentation with the Touchpad and it's your lucky day! I can answer your question:
- The Touchpad can ONLY properly play files with an MP4 extension. This is exactly the same as M4V, you can just rename it.
- The Touchpad can play High Profile H.264 encoded with x264 perfectly, with one caveat: You must disable B-Frames. Yes, this is painful. On the positive side, it handles CABAC and ALL other high profile features perfectly. It WILL play files with B-frames, but if you pause or seek in the video, from that point on it will stutter! Pathetic on HP/Palm's part...
- As you'd guess, a resolution of 1024 wide or less is ideal.
- Handbrake doesn't handle encoding well in this particular case. For the best quality and smallest file size (taking into account that B-frames are out of the question), it's best to use something that allows you to directly manipulate x264's encoding. I use a program called Mediacoder.
Here's how I recommend you set up Mediacoder (64-bit):
1) Ignore all the BS tutorial "easy setup" crap that pops up at first. Close it all, you just want the main Mediacoder window. Say "don't show me this next time".
2) If you already have it installed, go to File > Revert All Settings. This is to make sure there's not ghosts in the machine to screw things up.
3) Options > User Interface Mode > Expert Mode
4) Download these presets I made (attached). As noted earlier, these are for the 64-bit version only.
5) Pick what speed profile you want. The fast/slow HQ will be roughly the same quality, but different file sizes; same for the other quality settings.
6) Go to the "Picture" tab and put a check in the "resize" box. Pick whichever one starts with 1024 (the vertical dimension is set automatically but this must be redone if you have different dimensions on a new file). Of course, if your original file is smaller than 1024 wide there's no point in resizing at all.
7) Set your output and working folders; these can be the same thing, no problem. A folder on your desktop is probably best.
8) Drag your videos into the Mediacoder window and hit start. The "slow" profiles on my core 2 duo take about 1.2x the length of the original video on average. The fast ones are MUCH faster though, at the expense of filesize. Up to you. The "Slow HQ" preset will reduce 350 MB XVID tv show rips to around 200 MB each and the encode will be almost transparent.
9) When the encodes are finished, put them anywhere on your Touchpad, it'll find them.
If you ONLY want speed, Handbrake will do the job fine and much faster. Just be sure to set B-frames to 0. Touchpad handles CABAC, 8x8 transform, and weighted p-frames just fine.