Monday, January 8, 2007

One sighting of a user that has MythTV front+backend on PS3

MythTv's Wiki has a comment in the "Choosing Frontend Hardware" section that says that MythTV 0.20 does work on PS3 (frontend and backend).

However there is a catch ... you have to run the video in frame buffer mode .. apparently Sony currently blocks Linux from accessing the video card directly ... hopefully Sony will provide a better API.

Gentoo Linux on PS3

It looks like you build Gentoo linux on the PS3 according to this link:
http://planet.gentoo.org/developers/ranger/2007/01/03/ps3_32bit_userland_stage4_and_grp

This link talks about offering pre-compiled binaries, compiled on PS3 (since compilation can be slow with limited memory).
http://planet.gentoo.org/developers/ranger/2007/01/02/ps3_installcd_beta_hits_the_mirrors

According to PenguinPPC where I found the above link, they plan on hosting pre-compiled binaries for PS3 due to the limit memory of a PS3 (only 256 meg available to Linux). So might be a good link for the Gentoo lovers out there!

Here is a Slashdot article pointing to full install instructions as well.

16,000 chickens simulated on one cell

The link: http://www.spectrum.ieee.org/jan07/4837
From IEEE Spectrum - January 2007 (Pages 40 - 43).

IEEE Spectrum has a great article about the problems programmers have when trying to create parallel processing algorithms. But in the article they talk about a simulation done on a single cell processor .. where (in real-time) 16,000 chicken's actions were simulated .. key quote from the article:

"Imagine the biggest flock of virtual fowl ever assembled. Each chicken is controlled by a simple artificial intelligence program, operating according to a handful of rules. Each chicken wants to move toward the rooster but must avoid collisions with other chickens, fences, and the barn. To do so, each one must constantly check the position of its nearest neighbors and other objects in its environment and then decide how to move.
If that doesn’t sound all that impressive to you, consider this: all 16 000 of those faux chickens are doing this maneuvering at the same time on a single Cell microprocessor. It is a chore that would tax a rack full of conventional servers." (Spectrum Jan 2007 page 41)

Update:
Here is a link to a presentation where the "16,000 chicken" program is run and explained. You have to go about 32mins into the video to hit the chicken demo part.
http://www.csclub.uwaterloo.ca/media/Riding%2520The%2520Multi-core%2520Revolution.html

Compiling MythTV on PS3: use --enable-proc-opt

You can read the Google Groups Thread for more details.
Short answer .. use --enable-proc-opt

Theodore Murdock sent me this helpful note.
I suppose I should also mention that anyone who wants to compile MythTV also *must* use --enable-proc-opt

If you don't, MythTV will try to compile for a generic x86 processor, --enable-proc-opt allows it to compile for a specific processor architecture, which is something we need when we're compiling for PPC.

He also notes that using --enable-xvmc helps to avoid complaints about missing xvmc files ... however another user has posted in the google groups forum that:

Just thought I would point out that you can compile MythTV without XvMC support, and as there is no hope of it working at the moment that might be the way to go.

I think you will need to remove the XvMC libraries as it gets enabled automatically (usually) if the files are present. Relevant info:

"If you have the libXvMCW wrapper installed, then it will be
automatically enabled by the configure program and all of the available library assets will be utilized. However, double-check your ./configure output during MythTV configuration state whether it says "yes" after "XvMC support" (or XvMC pro support) or not, since some distributions do not enable XvMC automatically regardless of XvMC library found in /usr/lib."
taken from: http://www.mythtv.org/wiki/index.php/XvMC