Yes, it's really stupid and frustrating.

Here I have the ATRIX with all the accessories (for review) and I've been re-encoding videos to use with the HD Multimedia Dock. The videos are all encoded in a suitable format for almost every Android phone (MP4/H.264) and that is proven by the fact that the videos work fine on a Sony Ericsson Xperia arc and LG's Optimus 2X (two other phones I have at the moment).

However, do a large sized video and it fails - and it's not just the native ATRIX player, but other third-party ones too. It's so annoying as I really fancied being able to watch HD content on an HD TV (even if it does only output at 720p, unlike the LG that outputs at 1080i).

It must surely be a bug, as there's absolutely no way the phone couldn't cope with the video - at a pretty low bitrate (circa 1Mbps) compared to the 12Mbps video it can record using the camcorder function! That plays back just fine!!

 

It plays 720 just fine. In your video, you state you don't know if it's a software or hardware issue. In this case, it's software. Your video file in fact. You state it's 720p, which is just the resolution. What format is it in and what container?

 

I can't figure out what the right settings are though - given the same settings create video that works when at a lower resolution!

If the videos didn't work on any other Android phone, I'd accept they were totally wrong - but they do play on other phones. My videos are H.264 in a MP4 container. Ironically, some video files play fine if they're not re-encoded at all - but then they fill up the memory card!

I can only imagine it's not the video, but something else unique to the HD video being converted; perhaps the audio settings or something like that?

Touch wood, I've not had any problems encoding video for the DEFY.

 

atrix video conversion

Note: ignore the 'max size of 960x540' statement. That's all your going to see, but that's not the max size of video file that can be played. The phone is just going to downsize it to play on it's screen.