SoC 2008/x264/Speed Optimizations
This project is part of Google Summer of Code 2008.
|
Project Abstract
My goal is to search for speed optimizations in x264 (and, time allowing or if anything seems an obvious port, possibly a bit in vlc and ffmpeg as well). I intend to thouroughly profile the thing and find out where we might do better.
Implementation
Will be mainly on a day to day basis - find something, see if something can be done about it. My main development system so far was an Athlon X2 3800+, so I mainly did 64bit and MMX, some SSE code so far, but it recently lost its case to a new and shiny Q9300 (will be back in service once that case arrives - seems it may take a while). I intend to be learning a lot of SSSE3 and SSE4.1 and will hopefully find some uses for it.
Current Status
Battling with Hardware. Fedora 9 is said to have the latest and greatest of all distributions in regard to supporting the Intel Onboard-Graphics (it's just a little bit behind on the version number and i think most of the newer stuff is already in). However, my G35 mobo does not really like me yet. Some things still to be found out. Expect me to rant a bit on the channel if it was just another really bad day.
Other than that, I hope to get into vtune next week, maybe even try to get the free IDA going somehow. And then we'll see where that gets me.
Week 1
Downloaded free IDA 4.9 and demo version of 5.2. The free version works surprisingly well in current wine. Just some font problems (fixed by selecting another one) and window handling is a bit awkward sometimes. Successfully disassembled some linux programs. Unfortunately the free version doesn't do 64 bit code and newer SSE, and the demo is severely limited in other aspects (no saves, time limit per session).
But then again, so far good old objconv -fasm worked well enough, too. So IDA should be nice to have if needed.
Registered with Intel for non-commercial downloads and got Intel Compiler Collection, Performance Primitives and of course vtune, but vtune officially only supports Fedora up to 7 (and with stock kernel) currently. Will have to fiddle a bit with that in the next days (given the X problems I had even with the current driver, downgrading to 7 is probably not even an option).
After that, planning to do some initial profiling.
Schedule
Had a presentation on May 23rd (yeah, just the right time to buy and install new hardware). Will need to hand in the write up for all of it soonish. After that, mainly weather dependent. Cold heads code, hot heads need to be near (preferably cold) water. Well. Wasn't coding what nights were made for?
Other probable time constraints: Will have to juggle a bit between doing things for GSoC and thinking (and writing) about these things for my Thesis. Switching sometimes should help keep up motivation (and idea flow) for the other. Otherwise, nothing largish. Maybe a weekend trip or two, but nothing long lasting.
