Actually I faced most of the mplayer porting problems back in 770 days. It did not have Xv extension support, also sound output was done using esd. Both standard video and sound output were far from perfect. So just compiling mplayer with default settings resulted in a very poor performance. And first N800 firmware also caused a lot of troubles as I had to workaround various bugs in it.

Right now N800 has more or less usable Xv support (SDL is also using it for YUV surfaces). ALSA can be used for sound output. So just compiling a video player from sources should provide satisfactory results with quite little efforts. Finetuning it to get the best possible performance is a bit more work.

Video decoding (done by ffmpeg just like in VLC) also got a lot of optimizations over all this time, some of them were developed by upstream ffmpeg maintainers, I also contributed some patches upstream. But some codec optimizations are not available in standard ffmpeg at the moment. I hope they all will get accepted upstream eventually. All these optimizations can be found in maemo mplayer SVN ('libavcodec' subdirectory).

Aisu: Good luck developing alternative video players. Let me know if you need help or advice. I guess the first problem to solve would be display blanking prevention.

PS. Am I alone who thinks that the choice of name for this topic is rather bad (it is not descriptive at all)?