Haven't really seen any good threads on here regarding video playing on the Optimus One. We are going to discuss that in this thread. Good players, best formats, fast video converters for those formats, questions... whatever you need!

I'll start. Currently using MediaCoder 2011 build 5145. After making several attempts, I could obtain a video with minimum blockiness and lag on the O1.

Video: WMV8 480x320 1.5 MBps, Average Bitrate
Audio: WMA8 192 kbps
Container: ASF

All other settings to your liking. I am running stock ROM with Der Caveman's v3 kernel, and no overclock (just the ondemand governor with a minimum of 245). I used RockPlayer to perform these tests. A video with the above settings should play just about well (occasionally drops frames), and should have an exceptional image quality. It doesn't seem power-hungry either, 4 minutes of video took 1% battery or less (Wi-Fi off, Bluetooth off, GPS off, Data off, whatever background services I normally have open). People brave enough to overclock should get even better results.

As for storage space needed, a 60 MB video was converted to a 40.8 MB one using the above settings. A pretty good ratio, I believe. On my PC (Pentium 4 HT @ 3.53 Ghz, 2 GB RAM, Gigabyte GeForce GT430 1 GB VRAM), the conversion speed ratio was at least 2X, meaning it converted in half the length of the video (in my test case, it converted in 2 minutes).

Sorry for the long post. Anyways, I'm waiting for other video enthusiasts in the house to share their experience!

EDIT: It seems the file size of input v. that of output are not in a preset ratio. A downloaded video from YouTube gets doubled in size, @ 352x288 and 768 kbps video bitrate.

 

Double posting, cos no one wants to post.

You may also want to try Xvid video at 2 MBps Average Bitrate and MP3 192 kbps, they seem to actually be even less power-hungry than WMV. In 14:45 minutes of playback, with HSDPA on, the battery went down only 4%.