[maemo-users] H.264 playback

From: drfredc drfredc at drfredc.com
Date: Wed Sep 12 09:02:46 EEST 2007
While poking around the tableteer info, I ran into a chart of supported media player video file formats.  There are significant limits to frame size of various video formats.  Native video on higher end camera video is out of range.

> When my 512x288 at 29fps mp4 video is scaled to full wide screen, 
> the video details are lost as well as is overall viewability.  

The quality of HW scaling on N800 is excellent (bicubic according to S1D13745
TV-Out Mobile Graphics Engine product brief), so I don't think you would lose
many video details. Also scaling is performed by hardware and does not consume
any extra cpu resources, so there is no reason not to use it.

> It chops the audio into short blips while individual video frames take 5 or
> more seconds to load.  While the N800 doesn't technically lock up, the home
> screen becomes unaccessible so killing the essentially locked up video
> player is difficult to impossible without rebooting the machine.  At
> least when trying to view this particular video.

While H.264 has a good potential for ARM11 optimizations, mplayer does not
have any of them yet and I don't have any plans for adding such optimizations
for my own reasons. And AAC audio decoder is not properly optimized for ARM
in mplayer either. So using mplayer to watch H.264+AAC videos is not a very
good choice right now.

By the way, ARM has released some H.264 and AAC optimized libraries 
recently: http://arm.com/news/18441.html
Who knows, maybe Nokia can use them in one of the next N800 firmware updates
to provide H.264 video support in the built-in media player.

More information about the maemo-users mailing list