Any altivec experts? (H.264 codec)

"I see little enthusiasm for funding the guy behind freevec.org (at 30 Euros/hr, it would add up quickly)"

Sorry, I missed something.

Did you ask for a bounty creation to improve Altivec support for video decoding ?

If yes, I'm ready to participate in this bounty.

@Hans

Altivec super experts :

Tobias Netzel's
http://code.google.com/p/leopard-webkit/
he made the optimization for Euae jit PPC G4 and G5 for MacOsX PPC plus is the author of leopard and snowleopard porting of last webkit browsers and library ask Álmos Rajnai his direct contact.

Or Cameron Kaiser ... he did Teenfourfox browser for MacPPC and the G5 Altivec optimization for it (he is an amigan) and Tobias Netzel's know him but you can go in touch with him thru his project http://www.floodgap.com/software/tenfourfox/ or the MacOs 9.x classic
http://www.floodgap.com/software/classilla/

@tlosm

Yes I also think Álmos Rajnai might be good candidate, as he is an Amiga user, his work on EUAE has been amazing.

@LiveForIt

for the altivec of x1000 is better ask Cameron and Tobias becasue the instrucions of semi are similar to g5 and not to g4, probably Michael T. can gave a support about too, because his knowledge about x1000 after his optimizations for Euae jit on this machine... but expert for sure is Cameron because his g5 altivec optimizations on teenfourfox are incredible.

@zzd10h
Quote:
Someone else suggested it, but it's all just theoretical at this stage. We'd need a substantial bounty, though. A few hundred dollars isn't going to cut it.


@tlosm

Quote:
Sounds promising. Are either of them active AmigaOS 4.x users, though (or at least a user of other NG AmigaOS variants)? While any optimizations would benefit PPC Mac OSX too, it would be a bit cheeky to ask them to work on this for us if they're not even members of our community.

You're welcome to point them to this thread, if you are in contact with them.

Hans

asking the guy behind freevec.org for a quote is free so someone should do it. He aint cheap but i wouldn't mind paying him for 1-2 hours work.

@Hans

Cameron for sure have an amiga 4000T i never ask him if with 4.1 classic or not.
Tobias i dont know but help too much for fix the semi (x1000) performance of euae jit Almos for sure is in touch with him im not ,i just left some feedbeck about his webkit and see he fast reply.

for sure Cameron is a kindly person open to gave an hand when is needed.
if you need i will write him about and ask Almos for Tobias too.


there are some other guys really good in mac scene.
another one is the kiju (q) dev , the same dev who make wine bottler on mac or some one involved on macports, for sure good and experts in mac ppc programming but not in amiga, the good thing is gcc from mac ppc and amiga are really similar.

I am not sure everyone who were listed are expert in AltiVec ... but doesn't matter.

I am ok to ask to markos (from freevec.org) but whatever we choose, we have to:
1. Select few H264 videos to have the same common references
2. Measure the performance baseline with ffmpeg on selected machines
3. Profile to know if bottlenecks are really where we suppose
4. Define targets / expected improvements

These are prerequisites to any bounties or contracts.

@smf
1-2 hours work isn't anywhere near enough.

@tlosm
Yes, please contact them, and point them to this thread. If anything, it would be nice to get an opinion about the work from someone who knows more about altivec.

@corto
I'd like to add one more item to your list
Quote:
5 - Be confident that we can raise at least a few thousand Euros in a bounty.

However, that should be done after benchmarking.


Quote:
I'd like to see results both with and without SIMD on x86, ARM, & PowerPC. These should be with both audio and video output disabled, so that it's just the codec. I'm not in a position to run these tests myself, though.


Quote:
They're not bottlenecks, but a set of operations that are SIMD optimized on x86 & ARM, but not on PowerPC. In particular, there is no altivec code at all for videos with a 10-bit depth.**

AFAICT, operations such as iDCT have altivec versions for videos with a bit-depth of 8. However, it's hard to tell what the status is for other operations like the computationally-intensive qpel motion compensation. Figuring that out would require going through the code in more detail than I have time for.

I was hoping that a developer more familiar with altivec (and more time available than me) would be interested in taking a closer look. Links to the relevant PowerPC & x86 code are in the first post of this thread.

Hans


** NOTE: I have no idea how common 10-bit videos are. The prometheus trailer is 8-bit.

@Hans

Reimar Döffinger is part of MPlayerHQ team, and he knows AltiVec, he has worked on MacOSX PowerPC.

@Hans

I'm a layman without a clue about how much time it would require but you can be sure that i didn't think that if i throwed up 30-60 euros that the work would be done :D

@LiveForIt

Quote:
Okay, so he may have a good idea as to how much altivec code is "missing" in the H.264 codec, and whether it's worth adding.

Have you been in contact with him at all? If so, could you ask him about it (if you haven't done so already)?

Hans

@Hans

Ok! After work i will try to ask Almos for Tobias and Write to Cameron . Hope we will have a positive collaborations about.

@Hans
http://www.corecodec.com/products/coreplayer
http://www.corecodec.com/products/coreavc
http://www.corecodec.com/products/coreavc/guide

I dont know if some one check here
http://www.freescale.com/webapp/sps/s ... rview.jsp?code=DRPPCALTVC

@tlosm Some of us already did ... since AmigaBlitter previously posted this link

I didn't unpacked and read each file though.

@corto

dho! ... i didnt see the link one of my friend suggested it and i report .
ok waiting some reply from some one hope will help Hans

@tlosm

Tobias Netzel did the G5 optimizations for e-uae PPC JIT, and all I did was use that and build it for an OS4 target because PA6T & G5 are similar enough. No coding on my part; I wouldn't have a clue.

In any case, G5 and altivec aren't the same thing, and I don't know if those people you mentioned have experience with altivec instructions.

@MickJT

im sure Cameron Kraiser is 100% geek about optimizing with altivec , Teenfourfox browser is impressive for the performances of fast browsing and html5 video decoding and is optimized for g4 altivec and g5 altivec machine with two different version for g4 and g5 plus a version for the other ppc .
Hope he will reply soon.



another altivec expert is him

http://tmkk.undo.jp/lame/index_e.html <-- on the footer of the page there is the contact

Hi everyone,

hehe, it's interesting to read in a forum that people are thinking of contracting me. Disclaimer: I'm the guy behind freevec.org, aka markos, and I was a long time Amiga user as well (had A500/A500+/A4000+060, etc) until 1997. But I'm still very fond of my first computer and read some Amiga forums from time to time -and I would seriously consider buying a new X1000 if the price was lower.

Anyway, regarding the Altivec work, I can definitely say that I would do a substantial discount if only because it's one way to help my first computer love!

Don't hesitate to contact me for a quote, and I also mention in my blog that I offer free evaluation -what needs to be optimized, how long it would take, etc. Please read:

http://www.freevec.org/content/services

for details.

Would gladly offer my services to fellow Amigans!