Shallow Thoughts

The Final Day

How can it be the last day of LCA? Wait! I'm not ready for it to end yet!

Well, at least Friday was a pretty full day, starting with the keynote, Anthony Baxter's "One Snake Enter, Two Snakes Leave" covered the two upcoming Python releases: 2.X (a minor stability/feature release) and 3.0 ("the release which will break all your code").

I hadn't seen him give a technical talk before, only the talk he'd given on flashy talks last year at the LCA Speakers' Dinner, and I was curious about how well his style worked for a real talk. Very well, as it turns out -- he was entertaining, clear and still plenty technical. The video of the keynote is well worth checking for anyone who programs in Python and needs to know about the upcoming changes.

Next up was Ralph Giles' "Seeking is Hard", an explanation of the Ogg container format (as he recovered from running across campus to find a needed video adaptor to get his Mac to talk to the projector). I got a little lost in the discussion early on distinguishing packets from pages (someone asked what the motivation was for each, and that would have helped me too).

But the core of his presentation -- why seeking is hard (for a media format that has to encompass video as well as audio) -- was clear and interesting. Seeking means finding a file location corresponding to a specific time offset; Ralph discussed the difference between seeking to a file position directly proportional to the time (which works only in uncompressed formats no one uses any more), using a seek table (a good optimization, but they're often wrong so you can't count on them) and the real solution, putting timestamps in each page. He covered problems like keyframes (a video frame from which a set of subsequent frames are calculated, so you can't seek and then start playing right away; you have to search backward to the last keyframe) and multiple tracks (you have to seek in each track to get them all in sync before starting to play).

Quite interesting, and I understand video formats a little more than I did before (which was "not at all").

Of course, you have to laugh at the title of Matthew Garrett's talk: "Suspend to Disk: Why it doesn't work, can't work and never worked in the first place (and what to do about it)." And we kept laughing throughout the talk. Who knew that kernel swsusp was such a funny topic? But the talk was informative and detailed as well as funny ... a strong contender for best talk I saw at the conference.

After lunch, Keith Packard of Intel told of "Pain and Redemption on the Linux Desktop." At the beginning of his talk, Keith announced Intel's release of a Programmers Reference Manual for their graphics chipsets -- some 1700 pages of detail used in their current driver, all released under a Creative Commons license (no derivative works). Horray, Intel!

The meat of the talk was a discussion of problems with the current X model, and fixes for them, including lots of information about who was working on what. Sort of a "state of the server address".

Tags: lca2008, conferences
[ 23:44 Jan 31, 2008    More conferences/lca2008 | permalink to this entry ]

LCA Thursday

Thursday's keynote was Stormy Peters' "Would you do it again for free?" She talked about motivation: what motivates open source developers, and does paying them reduce the motivation to work for free? She reviewed lots of motivation studies (like the Israeli day-care experiment) and discussed the implications for open source contributors.

(During the Q&A period, she recognized one of the questioners and said "Oh, you're going to tell me how many 'um's I had." Indeed she did have a few, though not many for an hour-long keynote. But it made me wonder if she's in Toastmasters.)

Moving on to the tutorial slots ... Dangit, I got the time wrong on Wednesday and missed Rusty Russell's prep session for his Thursday morning hands-on tutorial on kernel hacking with lguest. He'd made it very clear that no one should come without being fully prepped, and indeed, I had severe doubts about my poor old Vaio's ability to survive a 2-hour session of kernel compiling -- certainly the battery I'd brought couldn't last that long without an external power source.

And my second choice, Malcom Tredinnick's tutorial on website performance, was packed to the rafters and not letting anyone else in. So I took the opportunity to catch up on some email and do some shopping.

I got back in time for Peter Hutterer's interesting talk, "Redefining Input in X". Finally, an explanation of what that confusing "core" terminology means in the xorg.conf file when fiddling with graphics tablets. Basically, X has two different sets of input events: core pointer, and XI (X input). But GIMP is the only Linux app that registers for XI events -- everything else only gets core events. So to deal with this, when X sees an event from an XI device, it also generates a core pointer event.

His real subject was a new model which would allow X to have multiple pointers and keyboards at once. X would have "master" (virtual) devices with which "slave" (physical) devices can be associated. It makes the event setup more, not less, complicated: for each physical input event, you generate not two but three events: an XI event from the slave, an XI event from the master and a core event. Maybe there's no way around that. His demo, showing two mice and two keyboards active at the same time, was quite fun to watch.

Skipping forward to the final talk of the day, it was a tough choice between Vic Olliver's talk on his "RepRap" 3-D printer, and Elizabeth Garbee's "Introduction to Open Source Animation". I finally chose the animation talk, because I know the Vic would have the RepRap at Open Day on Saturday.

Elizabeth is 15 and can already hold her own as a clear and confident speaker. She covered the pros and cons of a wide range of options for making animations with open source software, ending with a recommendation for her favorite, synfig. Hurray for smart up-and-coming Linux-using Chix!

Tags: lca2008, conferences
[ 17:52 Jan 31, 2008    More conferences/lca2008 | permalink to this entry ]

W-Day

Wednesday was W-Day -- the day I was giving my tutorial on GIMP Scripting, first thing after the keynote. (Cue portentous music.)

But first, the keynote: the day opened with a highly anticipated appearance by Bruce Schneier. He discussed the illusion of security versus the reality, and how to bring the two closer together. Most of his points were familiar to anyone familiar with his writing, but he's still an excellent and polished presenter. Worth noting: no slides, just Bruce. Worked great.

After the keynote I skipped the morning tea and headed over to the lecture room to make sure I had enough time for setup. (You never know when a particular projector and laptop will develop a dislike for each other, though I'm happy to say I've been pretty lucky with my Vaio.)

The talk went well. I had been worried about the code-heavy topic being too dry, so after watching Jacinta's coding talk on Tuesday I'd made an effort to find more graphics and add more variety to the slides. I think it worked -- I got laughs where I hoped for them, and people were certainly following closely, as they were quick to point out when I made typos or other errors in the live coding section. A great audience -- I hope I lived up to their expectations.

In the afternoon, Dirk Horndel's "Make hardware vendors love open source" was right on target and very well presented. (Again, no slides, and as with the keynote, there was no need for them.) Dirk offered plenty of food for thought, even for those of us who don't often interact directly with hardware vendors.

Following afternoon tea, I squeezed into Bdale Garbee's standing-room-only "Peace, Love and Rockets" presentation. He has a little board bristling with sensors (a pressure sensor for altitude, a three-axis accelerometer and I forget what else) that includes a processor and enough RAM to record a rocket's flight profile. It's all designed under the Open Hardware License and driven by GPL software, of course. Very cool!

Tags: lca2008, conferences
[ 15:27 Jan 31, 2008    More conferences/lca2008 | permalink to this entry ]