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OG Xbox Forums => Software Forums => Development => Topic started by: _zlinky on February 27, 2007, 12:32:00 PM

Title: Question For Openxdkman
Post by: _zlinky on February 27, 2007, 12:32:00 PM
Hey openxdkman, first of all i just wanted to tell you thanks for all your hard work and effort on your pbkit for openxdk.  I can't wait to see more from you smile.gif

I noticed that in your openxdk patch, you added MmClaimGpuInstanceMemory.  I've been researching this function for a long time now and still haven't figured out how it works or what it does.  So I was wondering, what exactly does it do?  And what is it used for?  Thanks.
Title: Question For Openxdkman
Post by: _zlinky on March 08, 2007, 07:43:00 AM
Wow, that's a very detailed description of how MmClaimGpuInstanceMemory works, thanks alot.  But I do have one more question though, about the registers found in the rules.  There are alot of registers that handle graphics in that rules file (i.e. UCHROMA, etc.), I was wondering if those registers would work on the NV2A ot just the NV10?  I haven't had any opportunities to find out for myself yet.
Title: Question For Openxdkman
Post by: ultrabrutal on March 28, 2007, 11:24:00 AM
Good to see that OpenXDK is alive again!  
Your lowlevel skills would be greatly appreciated in the XBMC community if you could help kick start GPU assisted decoding of HD content which currently is impossible for x264.  XBMC has a huge userbase where many are interrested in HD decoding.
Talk goes on about porting to other platforms, but there currently really aren't any alternatives, so the trustly old Xbox stays.
Step 1 could be to get GPU decoding going/implemented, step 2 could be to get XBMC compiling using OpenXDK, this could help further spread XBMC to the people and show the world that it's not always about new hardware all the time that I can actually keep old hardware alive if you just use it right (C64 forever!)
Step 3 could be full XDK compatibility so other homebrew could compile

Earlier a donation program for DVD menu implementation helped bring that about, if anything like that could help kickstart you maybe we can figure something out.

Tnx
Title: Question For Openxdkman
Post by: openxdkman on March 28, 2007, 11:57:00 AM
I see.
Feel free to use pbKit to make some experiment, if you are interested in switching from xdk to openxdk.
in pbKit.c check for "YUV", the bit can be flipped. I haven't tried but I guess that means RGB becomes YUV maybe that can help.

Shader type is set with two values. For now it's EXTERNAL (means we don't use the fixed function pipe line but shader we compile ourself with Cg Toolkit) and subtype is REGULAR. I added myself these new constants in Nouveau project header.

First, you should fully understand demo04 because you can do a lots of matrices calculation out of the 96 constants. It's possible to double that (192 constants: -96=>95) but it would imply bypassing a bit Cg Toolkit.

Last, you can try to change the subtype REGULAR for another subtype which slow downs a bit the shader execution but allows to write into constants, thus allowing successive shader iterations to make calculation evolve among the Constants. I haven't tested it.

Of course if h264 can't be done on HQ stream because of a bus physical bandwidth limit, it's over.

Master demo04 and Cg Toolkit and you will get many ideas for fast calculations with bare openxdk.

But, of course these tricks can be done with XDK too. Maybe they haven't been tried yet?

Only reason to port xbmc from xdk to openxdk would be to be allowed to publish binary legally. Since current situation doesn't stop anyone from getting xbmc, it's not sure the effort will be worthy.

I'm busy with minidash. PC0 version of minidash may open doors to a PC port (if nv40 is mastered). A dedicated PC0 forum has been created:
http://forums.xbox-s...p?showforum=507
Title: Question For Openxdkman
Post by: ultrabrutal on March 28, 2007, 02:16:00 PM
Yeah, OpenXDK was for legal XBMC binaries and other legal homebrews. Anyone would want XBMC in their house smile.gif I have 4 boxes already hehe

Sure a PC port with no Windows in the background via PC0 would make sense, but only if the Xbox resources are not enough which we hope/think they are not. There is still untapped power in the old box

PC hardware is expensive, especially if you want small form factor and low noise levels. Even the cheapest PC you can build, comes nowhere near the price or size of an Xbox. It even is very low power compared to a current PC
Title: Question For Openxdkman
Post by: ashlar42 on March 29, 2007, 07:43:00 AM
QUOTE(ultrabrutal @ Mar 28 2007, 10:23 PM) View Post

Sure a PC port with no Windows in the background via PC0 would make sense, but only if the Xbox resources are not enough which we hope/think they are not. There is still untapped power in the old box

Yes, but please... to be able to decode all HD streams in the future... one needs today a very powerful dual core CPU and a good GPU... how can you still believe that Xbox could be up to this task?
As of today XBMC can decode every SD content imaginable, no way it could do the same for HD. You'd always need to re-encode stuff and, frankly, with the amount of work involved... it kind of defies the purpose of having a small and handy box under your TV, if you have to spend hours in front of your PC...
Title: Question For Openxdkman
Post by: ultrabrutal on March 29, 2007, 12:53:00 PM
Without the use of the GPU, the Xbox is able to decode HD xvid (1280x720(544 oar). With new MPlayer with optimizations and still no GPU, it's possible to decode x264 at DVD resolution. Of course there is a step up to HD resolution (720p) but the GPU is much more powerful than the CPU.
The PC's you talk about uses the CPU for decoding and not the GPU, so no I do not agree a powerful CPU is needed. A 2 ghz single core PC can decode HD. 2.5 ghz is needed for full HD. Both without the use of the GPU.
1080p VC1/x264 is probably too much for the old box, but I'm fairly sure that atleast 720p is possible maybe even higher.