Wednesday, July 25, 2007

Need Help .. What else should be posted?

Since there doesn't appear to be much work on porting mpeg libraries to the cell processor in Linux (to make use of the massive parallel processors) ... What else should I write about?

Have a good post or link you want to see here? Just post it as a comment and I will add the really good ones as new posts.



gemmell said...

I'd like to know more about the Progress of MythTv on PS3. For instance, they say it's choppy due to the closed graphics drivers, but is that SD? Can we get the backend to pre-process it so that it's a smaller or more handle-able size?

PS3Penguin said...

I believe the choppiness comes from two issues. The first (as you mentioned) is the main processor not the cells are used for HD mpeg decode. The next issue is the video driver for linux is currently in "framebuffer" mode, not a direct accelerated access mode. Take any high-end linux box and run its video in frame buffer mode ..and you will see lag .. if not chop.

gemmell said...

So it is choppy regardless of resolution? I run on a projector (Infocus 4805) which has a native res of only 848x480. So I get no benefit from trying to run any higher than that.

PS3Penguin said...

Haven't tested it yet so not sure on full results. I would guess a standard def (640x480) should work ok .. problem is probably keeping up with the 4x increase in resolution for HD. My point was really that accelerating the MPEG decode using cells may not be enough .. what we really need here are some bench marks to measure raw frame rate when writing to the frame buffer under Linux .. then we would know whether or not the framebuffer is the issue or not.

Currently I run Myth on a dual AMD 64 3.2 GHZ .. for a while I had the video in framebuffer mode (I was using a third party on-board while I hunted for a good PCI-E card) .. I remember getting the HD content to play .. but almost all the CPU time was spent in the Xorg process .. writing to the frame buffer .. once I went to a real video driver .. the load dropped from 90% percent to 7%.

gemmell said...

Seems that at least one person has been able to get the PS3 to play videos from Mythtv using UPnP:

Could you post something on that?

PS3Penguin said...

Thanks gemmell that was a good link!