WebM - Open video & audio - in Fedora 14? Wed, May 19. 2010
HTML5 provides <audio> and <video> tags for sound and video content. However, every browser seems to support a different combination of codecs and containers for these tags. Open source projects have of necessity only been able to support open formats, but proprietary vendors have been reluctant to throw their weight behind those open formats.
At GoogleIO today, Google, Mozilla, Opera, and 30+ other partners announced WebM, an open source mashup of the Matroska container format, Vorbis audio codec, and newly-open-sourced VP8 video codec. The intention here is to provide a "safe", open-patent-grant format that both open source and proprietary products can integrate. To that end, the WebM code is licensed under a BSD + patent grant license. And, of course, with Google/YouTube supporting this format, there will be a lot of content available.
So how does this touch Fedora? It looks like current Firefox nightles support WebM, and gstreamer support is in the works; hopefully, this will land in time for Fedora 14. For rpmfusion/ffmpeg users, WebM support is in today's upstream ffmpeg release.
Mozilla running Unit Tests on Fedora Wed, May 19. 2010
Mozilla uses CentOS for their Linux builders. They have up to this point also been running their unit tests on CentOS, but Armen has now switched the Linux unit tests over to 32- and 64-bit Fedora. This is a great win, because it means that Firefox will be tested against a more-current environment.
Fedora-Advisory-Board Thu, Apr 22. 2010
Within the Fedora project, there is a mailing list that perhaps doesn't get as much attention as it should: advisory-board. The name itself seems a bit cryptic, but this is the place that the Fedora Project Board has public discussions. It's the place where board proposals get hashed out in public, and it's a good place to bring items to the attention of the board. Come and join the conversation!
Network Storage: Loopback ext3 on NFS? Really? Thu, Apr 22. 2010
One interesting find I made while working with the Seneca students on Fedora ARM was that a loopback filesystem hosted on top of an NFS share can outperform the NFS share. Yes, it's counter-intuitive, because that would seem to introduce additional layers of processing, but I think it makes sense.
When using NFS, file metadata management is performed by NFS. When loopback-mounting a filesystem in a file hosted on NFS, the file metadata management takes place entirely on the local system -- NFS merely provides a data store. In this sense, it's not much different from iSCS, because the loopback filesystem can't be readily accessed by two separate hosts at once.
In fact, on a small ARM system such as an OpenRD-Client, loopback-ext3-on-NFS over GigE handily outperforms both Class 6 SD and a local USB-PATA drive.
Why not just use iSCSI? Well, for reasons I haven't yet determined, the Fedora iSCSI initiator doesn't work reliably on ARM-- under heavy load, it sends invalid opcodes to the target. This sounds like an alignment issue, but alignment fixups don't cure it. Investigation continues...
Seneca and the Fedora ARM Secondary Architecture Thu, Apr 22. 2010
ARM processors power the digital mobile age. Billions are produced per year, ending up in the majority of cellphones as well as in e-book readers, plug computers, the OLPC XO 1.75, tablets, netbooks, intelligent RJ-45 network jacks, and even microSD cards.
The Fedora ARM Secondary Architecture project has done a great job of porting Fedora releases to ARM. To assist this initiative, this semester's Software Build and Release course at Seneca (SBR600) put together a new Koji build farm for the ARM architecture in preparation for using koji-shadow to follow the primary architectures. It's been a fascinating and challenging project -- working with cross-compilers, emulators, and hardware with much smaller configurations than standard PCs. A large amount of effort was spent benchmarking various configurations to determine optimal memory and storage arrangements and to compare emulated vs. hardware ARM performance to guide the configuration of the build farm.
So now we're at the end of the semester. Where do things stand?
- We have a working Koji build system, with two hardware builders plus emulated (VM) builders
- Since we're at the end of the semester, things will be quiet for the next week and a half, but then we've hired a graduate to work on this full-time (intros coming up shortly )
What's next? In May-June we expect to:
Running Fedora-ARM in emulation under virsh Thu, Mar 4. 2010
The Fedora qemu-system-arm package provides pretty good ARM processor emulation, which can be used to run the Fedora ARM secondary architechture. This is an easy way to get started working with ARM -- for example, while waiting for your plugcomputer, beagleboard, or OLPC XO 1.75 to arrive
The previous wiki notes on using ARM with QEMU didn't cover using qemu-system-arm under libvirt management. This meant that you couldn't easily take advantage of libvirt benefits such as automatic network setup (with DHCP and NAT), the virt-manager GUI tool, guest autostart, or disconnection/reconnection to the console.
I've updated https://fedoraproject.org/wiki/Architectures/ARM/HowToQemu to include some basic notes on setting this up, and provided some files to simplify and speed up the process. Jump in and join Fedora-ARM, the water's nice!