Gource visualising feng’s history — A story of Radeon

[youtube https://www.youtube.com/watch?v=XG-SiE7ciuU&w=853&h=480]

Or see this on YouTube — and yes this is quite ironic that we’ve uploaded to YouTube the visualised history of a streaming software stack.

The video you can see here is the GIT history of feng the RTSP streaming server me and Luca are working on for the LScube project, previously founded by the Turin Politechnic, visualised through Gource.

While this video has some insights about feng itself, which I’ll discuss on the mailing list of the project soon enough, I’m using this to bring home another point, one even more important I think. You probably remember my problems with ATI HD4350 video card … well, one of the reasons why I didn’t post this video before, even though Gource has been in tree (thanks to Enrico) for a while already, is that it didn’t work too well on my system.

It might not be too obvious, but the way Gource work is by using SDL (and thus OpenGL) to render the visualisation to screen and to (PPM) images – the video is then produced by FFmpeg that takes the sequence of PPM and encodes it in H.264 with x264; no I’m not going to do this with Theora – so you rely on your OpenGL support to produce good results. When 0.24 was being worked on (last January) the r700 Radeon driver, with KMS, had some trouble, and you’d see a full orange or purple frame from time to time, resulting in a not-too-appealing video. Yesterday I bit the bullet, and after dmesg has shown me a request from the kernel to update my userland, I rebuilt the Radeon driver from GIT, and Mesa from the 7.8 branch…


No crashes, no artefacts on glxgears, and no artefacts on Gource either! As you can see from the video above. This is with kernel 2.6.33 vanilla, Mesa 7.8 GIT and Radeon GIT, all with KMS enabled (and the framebuffers work as well!). Kudos to Dave, and all the developers working on Radeon, this is what I call good Free Software!

Just do yourself a favour, and don’t buy videocards with fans… leaving alone nVidia’s screwup with the drivers, all of them failed on me at some point, passive cards instead seem to work much longer, probably because of the lack of moving parts.