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Present Perfect

Filed under: General — Thomas @ 14:40


Why I stick with Red Hat/Fedora

It's pretty simple. A bunch of their engineers go out to see a movie. Three of them blog about it.

And not a single one of them manages to mention the utterly delectable Kate Beckinsale.

These guys are just impossible to distract from whatever their goal was. And that's why, kids, Red Hat/Fedora will always be a top notch distro.


Whilst on the subject... Went to see Intermission because we were too late for Big Fish. Quite ok. Saw Bully over the weekend. Alrightish, but man, are those kids stupid in the movie. Based on a true story, but I hope they were slightly brighter in real life.

Saw "Varsity Blues" yesterday. I can honestly say it was the best movie I've seen all yesterday.


So Ronald and I took over maintainership from Ted. I've started by applying all the patches that were still applicable to the 2.6 branch, then tried to branch, but failed because Ted apparently had already branched for 2.6.

Updated my local GNOME Maintainer's Guide with all the steps I'm taking while I go along.

After sorting out the branch mess, I started to work on some of the bugs in 2.7.

I wrote a command-line CDDB client for the CDDB slave so I could reproduce some of the bugs more easily, which caused some segfaults when run together with gnome-cd. It was like an itch you're trying to scratch that keeps running away from your nails - I spent quite some time figuring out exactly what was going wrong. The setup is quite complicated, with clients requesting a slave client, which is instantiated through CORBA, which causes the CDDB slave component to create a slave object to handle the requests, and then signal the slave clients.

One of the problems was that each slave client got notified of every lookup from every slave client, so my command-line client forced gnome-cd to believe the disc had changed :)

Anyways, after restructuring the code, adding comments and hacking notes, and adding some code to set the CDDB server to protocol level 6 so it gets UTF-8 responses, things are starting to come along quite nicely.

I also added error checking to the CFLAGS, and then spent some time fixing all the warnings/errors that generated. Seriously, everyone who is against -Wall -Werror is probably just writing sloppy code. That doesn't mean I write good code; but I know I write better code with -Wall -Werror, and I know ANYONE writes better code with it.

It's actually quite nice to work on someone else's code as a new maintainer; 90% of the work is already done, and you can refactor code more easily since you have a reference version that works.

So you just start learning the code by tackling some of the simpler bugs, adding comments to functions as you go, and taking notes on how you work, until you've seen and changed the whole code.


The basic setup to replace camserv works fine. Monkeys are being spanked at an alarming rate. I hope we get our server soon so we can make a continuous stream available to the outside world.

Today we're going to try and stream Ogg/Theora.

Filed under: General — Thomas @ 14:39



Did a lot and very little at the same time. Went out with collagues, helped a friend of mine move (I hate moving, and having to move boxes to the center of a city like Barcelona is even worse), went out blading, had my niece over for a few hours, played some SSX3, went to have dinner with two friends at their place (with the best salad I've eaten since moving here).

Got a nice mail from someone about the ipw2100 modules I made. Need to update them to 2.6 kernels, I think I have the mechanism worked out now.


Wim started today, yay. I'm stuck on trying to figure out a way to help negotiation wrt. fixation a little.

Join Ross

"Grab the nearest book, open it to page 23, find the 5th sentence, post the text of the sentence in your journal along with these instructions." Suggestion 2: Pay attention to your problems.

I had to cheat though, the first book only had three sentences on that page.


Last week I managed to embarass myself again for a change. I'd been looking for a tango place when I moved here. The first one we went to last month was closed for renovation. I had found some posters around our place with "Tango" on it in a nice big font, and a stylised dancing couple. It claimed the place had three evenings with orchestra. So last weekend we went there, got in, paid 10 euros each, and entered the big room.

Looked like a nice enough dance hall, but everyone in there was at least 50. While it's not uncommon to have older people on Tango evenings, there was no one our age at all. Also, the music wasn't tango music, but Spanish popular music. After some walking around and thinking, I realised that the place itself was called "Tango". Sigh.

At least I know where to send my parents to next time they're in town.

Filed under: General — Thomas @ 14:38



Working is becoming more and more fun. Working on streaming and seeing it evolve is rewarding. I must say I'm quite impressed how decent the 0.8 GStreamer core has become; most of my time is spent looking at fixing plug-in issues.

David did a great job on the caps rewrite; he put in stuff he wasn't sure of yet how to use (like, all of the fixating hooks), but as I learn how it works in actual use day by day it seems to get easier to fix bugs on it, and I get the feeling he had the right hunch. I'm not sure he's yet able to express exactly how the hooks are supposed to be used :) but his gut instinct seemed to point in the right place, and now it's up to fixing plugins.

Benjamin has been plugging memleaks all over, which is great. I should really build a custom valgrind that works with GStreamer, my system one has GStreamer running into some hardcoded limits.

Ronald meanwhile is beating the crap out of any media file we're currently not playing. The number is shrinking rapidly. One of these days someone is going to add mp4v/mp4a support to qtdemux, which I need for some other project.

All in all, it's moving at a pretty quick speed.

This week, I dove into the v4lsrc element, which didn't work with the qc-usb drivers because those drivers use an internal buffer of only one frame, and Ronald coded the v4lsrc element to work in streaming mode, which requires at least 2. After some fiddling and reading, I learnt that this specific driver has a hack which enables streaming mode by exposing two buffers, with both buffers being the same physical ones in the driver.

That didn't get it to work yet either. But this was due to some code in v4lsrc that only used the buffer's pointer to check which buffer to requeue in the driver, and since the driver is handing the EXACT same pointer this didn't work. So, attach the frame number as private data to the buffer, and use this to requeue the proper frame, and v4lsrc was fixed.

Next in line was rewriting TCP elements. As I've blogged before, this entailed modelling four elements (two servers and two clients) on the fdsrc/fdsink elements. At first I was just sending over raw buffer data. That, combined with an element that is able to figure out correct buffer size for raw video frames (since you can calculate this based on the output format), allowed us to stream raw video.

This breaks of course when you want to stream encoded video. There's no way to transfer the buffer size properly, so the second pipeline cannot chop up the incoming data to one buffer per frame.

So, on to writing a simple protocol to transfer GstBuffer, GstCaps and GstEvent over the TCP link. It's a bit messy at the moment, but I got it to work today. I did spend three hours over a random bug that in the end was caused by my own stupid code that freed a caps structure right before returning it :/ (In my defense, I haven't had a decent night of sleep all week).

I used to only work on audio, and am slowly picking up on video-related issues. The fun thing about hacking video is that the experiments and bugs are very rewarding. For example, as soon as we got JPEG streaming to work, we dropped down the quality level to 0, which looks like this. (It's a lot cooler if you see it move :))

Bugs are fun too. Here's a wacky colorspace conversion bug. And combining crap with bugs gives this.

It's fun to invent a protocol, as simple as it is, and write the code to handle it, all in some vacuum where you don't have to care too much yet about other opinions. It's a small simple unit with a simple design that I can easily put together, and I like doing stuff like that. I had the worst headache yesterday when I decided to do this, and having fun with it all day made my headache seem to go away.


So, yesterday I woke up at 6 with a splitting headache, took something, went back to sleep, woke up againt at 7.30, huge headache, took something, back to sleep, woke up at 9, still a huge headache. It lasted all through the day.

At night, early to bed, but no chance of getting any sleep. Got up at 1 again and started to look at doing a decent addressbook OpenLDAP setup, and this time documenting it properly with my new docbook-xml-template. Was happy to figure out how to make computer output look like a computer screen, and simple stuff like that. Hope to finish this simple HOWTO as soon as I figure out some of the more intricate details. But this time I want the stupid addressbook setup to Just Work.

I also tried out conglomerate quickly. I'm not sure it works well yet, but it looks sweet for sure, and it seems pretty responsive. I should check up on if I can use it do to real work yet.

New employee

arrived today, yay ! Johan and I are excited to have someone extra in our huge office. We're only taking up a quarter of the space right now. Granted, we don't have our definitive furniture yet, and we're still missing the pool table, pingpong table, couch, plasma TV, sauna, shower, and minibar. But still ...

Filed under: General — Thomas @ 14:37



A disheveled young man knocked on my door last Wednesday claiming he was a friend of 'the GNOME release manager' and if I could put him up for a few nights, together with his girlfriend. He was tired from a long trip from Australia to Europe and all through Europe. So I took pity on him and took him in.

In the evening my home server started beeping loudly again, and he immediately came to the rescue. First he helped me get lm_sensors running on the machine, then we used gkrellm to check on the temperature. His hunch was correct; at 60 degrees C it started beeping. He started to fan the open computer with a book and made it drop to 50 in a minute, which stopped the beeping.

So that explained why it was crashing. Now to see what caused the CPU to go crazy. Which was pretty much my own dumb fault - I was running Xvnc on the machine for some applications, and the screensavers take it to 100% after a few minutes.

So taking in a complete stranger already paid off on the first day. Of course, the second day he took over the PlayStation and Entered the Matrix. I hope he gets out of Tunnel A7 by the time his plane to Australia leaves.

It was nice meeting thaytan and Jaime, hope they have a good flight home.


Nice to see us getting a warm reception. It's also nice to be able to code a little again. I checked GStreamer's tcp elements and found they were done differently than I would expect. The server was done in the source element, and the client as a sink. This means that you need to start the consuming pipeline first, and the producing pipeline after that. Also, the server was set up to be able to handle multiple connections, but to me it makes little sense to have the start of a pipeline take data from multiple elements.

The code was outdated too, so I made a bunch of new elements, where source and sink are implemented as both client and server. Then we tested them by streaming videotestsrc. Now I need to figure out how to add them to the testsuite properly.

I made all the elements blocking, since our filesrc and filesink are blocking too. But this might not be what we want.


So, Ted passed on maintainership to Ronald and me. I commited a few of the easier patches for a 2.6.1 release in time for the 2.6.1 GNOME release. Now we need to go through the rest and pick out the ones we can apply before branching for 2.7

Filed under: General — Thomas @ 14:36



Had quite a productive weekend. First of all, I got off my ass and tried out the Intel Pro Wireless 2100 drivers on my laptop. I had bought driverloader, which worked quite well, but I'm getting tired of having to download stuff each time I upgrade my kernel, and of course I actually forget to download the RPM before upgrading in the first place.

Of course this gave me a good change to test my kernel module packaging strategy again. Fifteen minutes of work gave me a loadable ipw2100 module (without WEP, at first), just by running ./configure and make. Five more minutes gave me a set of packages for it.

Then, I enabled WEP and rebuilt the hostap packages from the QA submission queue at www.fedora.us. I had a problem with the function call being used from hostap not being versioned. After some thinking, I figured out that this was because the hostap package didn't include a hostap.ver file that actually does the symbol redefining. So I changed the hostap package to include that, rebuilt it for four archs and four kernels, and then rebuilt the ipw2100 packages for the same. And lo and behold, the packages worked. So if you have Fedora Core 1 and an ipw2100 card, *please* test these packages together with these..

Don't forget to download the firmware as per the instructions on the ipw2100 project site, and install it in /etc/firmware.

Next step is to update my kernel module stuff to 2.6, but I'm not looking forward to that. AFAICT from discussing with people it seems there is no decent way of building kernel modules against a read-only kernel-source tree. Moreover, Arjan seems to say that to build kernel modules for a kernel/arch combo, you need that exact kernel package installed as well. That will probably make it harder to do mass builds of kernel modules as well. Sigh :)


I've been wanting to write a usable DocBook template tarball for quite some time. There are a couple of "guides" I'd like to do and every time I work on projects that use DocBook there is always something tripping me up. Between xmlto breaking in TeX processing for PS and PDF, or the docbook2 tools insisting on downloading SYSTEM identifier stuff from the net, there just is no foolproof way of building this stuff.

So, after a day of trying to write somewhat clean make rules and .m4's, I have a template tarball project that builds documentation, passes make distcheck, and easy to use in other projects. Yay me.


So, it's official: Fluendo is launched ! In a nutshell, we're going to write a free software streaming media server, on top of GStreamer, making it possible to do completely free software-based video streaming, using royalty-free codecs.

We decided some time ago to fund Xiph.org, since to reach our goal we actually *need* a decent royalty-free video codec. Theora is very close to what we need at this point; as soon as the bitstream specification is fixed, all videos created with that version of Theora will be playable by future versions of the library. This will hopefully have the same effect as the Vorbis Beta 1 release had for audio.

And even if it doesn't, it still enables us to provide this server working completely, for free, and hopefully, allow distributors of Linux to pick it up, distribute it, as well as the GStreamer stack with playback and recording applications. I can understand it doesn't make sense to do so if you can't distribute video codecs as well, so once Theora is ready to be distributed, I hope this changes the field a little.

Anyway, I'm pretty psyched we can announce all of this. There's always a fear of turning over to the dark side without realizing, but being able to start a company with these goals is exciting, and I hope we do well. We're moving in our new office this week, and our new collague is arriving next week.

The nice thing was being able to use my docbook-xml-template to generate the press release easily :) So the next one we do will just be a matter of filling in the content and running make.


Ross is not the first one to link Fluendo to influenza. I really like the name, it took us long enough to come up with something that we liked, still had a domain name available, and not too much GoogleJuice. I'm wondering though if non-hypochondriac people make the same link between Fluendo and influenza ?

Also, Ross ran away with a "might happen" newsbit and posted it, probably to put some pressure on us to deliver :) All I can say is that we'd like to, but aren't sure yet if all the pieces will be in place.


Read Jorn's latest entry. Good to see Muine progressing. Only, Jorn is switching backends (again). I have a lot of respect for Jorn, and he's a talented coder, but I really have to wonder *how hard it can be to do some bug reporting*. The number of times jorn was in our channel, multiplied by the number of bug reports by him, multiplied by the number of mails to our mailing list, are easily countable on the fingers of my two hands.

People seem to think stuff should just fall out of the sky. Sometimes it does, but when it doesn't, it doesn't hurt to poke the clouds a little so they drop some more stuff you want :) How's about some simple feedback about the framework you're coding against ?

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