Category Archives: Red Hat

Brno GUADEC Call for Papers!

I would like to give everyone a friendly reminder that Saturday the 27th of April is the official deadline for the GUADEC 2013 Call for Papers. So make sure to get your proposal submitted.

We hope to have a wide range of talks this year, including talks on related subjects such as Wayland and Multimedia, so don’t automatically assume that you will not get a talk approved because its not ‘pure GNOME’.

GUADEC this year will be in Brno in the Czech Republic, so I hope to see as many of you as possible here.

Open Source software and crowdsourcing

So thanks to crowd sourcing we are getting a lot of linux games coming out, titles such as Double Fine Adventure, Wasteland 2, Spaceventure, Project Eternity, Hero-U: Rogue to Redemption, Godus, Torment: Tides of Numenera,Arcade Racer and a lot more are all coming to the Linux platform thanks to crowdsourcing.

The question that one would want to answer is if crowd sourcing can work for open source projects creating useful software or other kind of tools. One project I am really hoping gets funded currently is Geary, the open source email client from the great guys at Yorba. Not that I personally are desperate for a new email client, I am a happy user of the Evolution email client, but I also know that email is a very personal thing for many people and an area where having different client offering different experiences might make a difference. Also proving that a non-profit outfit like Yorba can fund themselves through crowdsourcing is an important thing to demonstrate. So I have already pledged to Geary and I hope you will too.

They are not the only such project out there of course. Another project I have pledged to is the Phantom Open Emoji project which wants to create a full set of liberally licensed emoji/smileys covering the Unicode 6.0 set of over 800 such things. They only need to reach 25,000 USD in funding to create the full set, so I hope they can make that goal and we can then include support for these in Empathy.

The final project I want to mention is the OpenShot kickstarter. While I do think the best solution would be a GStreamer based one like PiTiVi for various reasons I am still happy that this kickstarter has reached is minimum funding goal already as it is does show success at funding open source development projects.

That said what strikes me is that the 3 open source projects above are all actually quite cheap, in the sense that the funding amounts they ask for are not high at all. And when you consider that games such as Torment reach 4 million USD in crowd sourcing funding one could wish that people would be a bit more prepared to bankroll open source projects. That said I guess just like games had their breakthrough moment with the Double Fine Adventure kickstarter, maybe open source development needs its own shinning star to lead the way. So if you haven’t already please pledge to one or more of the open source efforts above.

There will be more attempts of exploring this space though I am sure, I am even planning to be involved in one such effort myself, but more details on that later.

GStreamer Hackfest in Milan

As those of you following the GStreamer development mailing list or the GStreamer Google Plus profile know, we have been having a GStreamer hackfest in Milan over the last few days. We have 17 people here, all hammering away at our laptops or discussing various technical challenges sitting at a nice place called the Milan Hub.

A lot of progress has been made during these days with some highlights including work on fixing the use of Gnonlin with GStreamer 1.0, which is a prerequisite for getting PiTiVi and Jokosher running with GStreamer 1.0. Jeff Fortin, Thibault Saunier, Nicolas Dufresne, Edward Hervey, Peteris Krishanis and Emanuele Aina has all been helping out with this in addition to fixing various other issues in PiTiVi and Jokosher.

Sebastian Dröge has put a lot of work during the hackfest into providing the basic building blocks for doing hardware codecs nicely in GStreamer, and Víctor Jáquez has been working on making VAAPI work well using these building blocks, with the plan among other things to make sure you have hardware accelerated decoding working with WebKit. In that regards Philippe Normand has spent the hackfest investigating and improving various bits of the GStreamer backend in Webkit, like improving the on-disk buffering method used. Also in terms of hardware codec support Edward Hervey also found a bit of time to work a little on the VDPAU plugins.

Speaking of web browsers Alessandro Decina has been working on porting Firefox to GStreamer 1.0, he has also been our local host making sure we have found places to eat lunch and dinner that where able to host our big group. So a big thank you to Alessandro for this.

Wim Taymans has been working on properly dealing with chroma keying in GStreamer, improving picture quality significantly in some cases, in addition to being constantly barraged with questions and discussions about various enhancements, bugs and other challenges.

Edward Hervey has in addition to help out with GNonlin also been working on improvements in our DVB support and improving encodebin so that you can now request a named profile when requesting pads, the last item being a crucial piece in terms of allowing me to proceed with Transmageddons multistream support.

Stefan Sauer spent time on fixing various bugs in the GStreamer 1.0 port of Buzztard and a first stab at designing a tracing framework for GStreamer.

Arun Raghavan was working on various bugs related to Pulse Audio and GStreamer and also implemented a SBC RTP depayloader element for GStreamer.

Tim-Philipp Müller has been working on implementing a stream selection flag in order for GStreamer player to be able to follow any in-file hints about which streams to default to or to not default to for that matter.

As for myself I been mostly working on Transmageddon trying to get the multistream and DVD support working. Thanks to some crucial bugfixes from Edward Hervey and Wim Taymans I was able to make good progress and I have ripped my first DVD with Transmageddon now. There is still a lot of work that needs doing, both in terms of presentation, features and general robustness, but I am very pleased by the progress made.

Title selection screen, needs a bit more polish, but getting there.

Transmageddon screenshot ripping a DVD
As you see above you can now choose to transcode to different codecs for each sound stream, or drop the streams you don’t care about. The main usecase for different codecs is to you a different codecs for surround sound as opposed to stereo or mono streams.

A big thank you to Collabora and Fluendo for sponsoring us with dinner during the hackfest.

Also a big thank you to Collabora, Fluendo, Google, Igalia, Red Hat and Spotify for letting their employees attend the hackfest.

Taking on a new job at Red Hat

So I assume most of you have read Jonathan Blanfords blog post about leaving Red Hat and me taking over for him as head of the Red Hat desktop team. First of all I would like to thank Jonathan for both his contributions to GNOME and Red Hat, but also for being a good friend for over a decade now. Luckily Linux is also a major piece of his new job, so I am certain we have not seen the last of Jonathan in the community.

For the outside observer I wouldn’t expect any immediate visible changes to happen as part of this transition. My job is to follow up on the many great initiatives that Jonathan started here together with the rest of the team. One major piece I will be tackling is making sure we in the Red Hat desktop team work even closer with the Fedora community to bring forth some great improvements to Fedora and created an even more integrated and seamless experience for those wanting to use the Fedora desktop. This ranges from working with the Fedora team on a new software installer to working on getting Wayland ready for deployment in Fedora. Apart from that we will of course continue to work with the GNOME community on pushing GNOME 3 forward. I strongly recommend following Matthias Clasens blog to get the latest and greatest news on our efforts around GNOME 3.

I hope to post to my blog more frequently going forward to highlight exciting developments the many great projects the Red Hat Desktop team contribute to, like GNOME, LibreOffice, Firefox, Spice, Evolution, X Window/Wayland and more.

Steam on Fedora – Lets get gaming!

As you probably already know Steam is now available for Linux. While it is currently officially only available for Ubuntu you can run it on Fedora too. Tom ‘Spot’ Callaway has made this yum repository available. So just put the .repo file you find there into your ‘/etc/yum.repos.d/’ directory and you should be able to do ‘yum install steam’. I been running this repository through the beta period and the games I tried so far works great. Crusader Kings 2 is my clear favourite so far.

A screenshot of Steam running on my Fedora 18 desktop –Screenshot of Steam running on Fedora

More hiring! Join the Red Hat desktop team and make a difference!

We are looking for some more people to join the Red Hat Desktop team. We have some flexibility on the tasks we need these new hires to do, so we are casting the net wider this time. We are open to candidates from anywhere in the world where Red Hat has an office. For the right candidate working from home is an option, but you would still need to live in a country where we have an office. That said candidates interested in joining the 500 people strong and growing team at the Brno office in the Czech Republic will be preferred, especially in cases where we have multiple candidates with similar skill levels.

We are looking for people who would be available to join Red Hat sometime this year, so if you are a student and graduating this summer you can still get in touch. We don’t have a hard list of requirements, but of course experience with any of the below items or similar will increase the likelihood of us being interested, and candidates with existing open source contributions will always be preferred over candidates who has never contributed to an open source project before.

  • C/C++/Python/Vala
  • OpenGL/Clutter
  • JavaScript/HTML5/WebRTC
  • X Windows
  • Touch screen technologies
  • GStreamer
  • D-Bus
  • LDAP/Active Directory

So if you want to join the worlds leading Linux company and help make the desktop rock, please send an email to Tyler Siprova who handles the hiring process for us in the Desktop team. She can be reached at tsiprova(at)redhat(dot)com. Be sure to refer to this blog entry in your email so she knows the context of your application. Be also be aware that I will be at the FOSDEM conference in Belgium in February, so if you are interested I would be happy to sit down with anyone interested to talk about the opportunities we have here at Red Hat, so if this is of interest be sure to request for such a meeting to be set up in your email to Tyler.

Making Firefox love your GNOME Desktop

One thing we are doing here at Red Hat Brno is maintain Firefox for Fedora and RHEL. The job is mostly focused on making sure we have Firefox available on all RHEL versions with all the latest security fixes, but it also gives our great team of Martin Stransky and Jan Horak some time to work on adding new features to Firefox to make sure it feels like a more integrated part of your desktop. They are currently working on 3 such features that you will hopefully be able to enjoy soon. The first is a patch to inhibit the screensaver when you are watching HTML5 or Flash content fullscreen. So if you are annoyed by having to move your mouse every 3 minutes to avoid the screen dimming when watching The Daily Show this is the fix for you. The second item they are working on is enabling the GStreamer backend in Firefox on Fedora. Which means that if you install for instance H264 support for Totem you will also have H264 support for HTML5 in Firefox. And finally there is also ongoing work on adding support for GIO in Firefox to make sure that any setup that works with GIO in terms of remote file access also works with Firefox, this latest task is taking some time though as it is currently blocking on some code refactoring in Firefox.

A Linux Game Changer?

So the Linux based Steam Gaming Console has been relased, or at least one version of it. It is called Piston and it seems quite nice looking.

Personally I think this device has a potential to truly transform the Linux desktop and gaming market. If this things takes off it could for instance make linux drivers the top priority for the makers for graphic chips. And people specalizing in gaming oriented high end PCs would also be likely to start offering those machines with Linux.

So I don’t know about you, but I will for sure buy one of these boxes when it comes out :)

Further progress on multistream Transmageddon

As mentioned in my previous blog entry I am working on multistream handling in Transmageddon. Not been a lot of changes, but I have been able to put in a little time here and there. The changes needed to accommodate this have also cleaned up the codebase quite a bit in my opinion, moving from a forest of variables to a list of python dictionaries. This change makes keeping track of whats happening in the codepath a lot easier as I can now just print the dictionary from the list to see what all relevant values are at a given point. Anyway a little screenshot below to show where I am at:

In-progress support for multiple audio streams.

Still quite a bit of work to do to clean up the codebase and decide how certain things are to be handled (or not handled), but it is getting there. Screenshot above actually demonstrates one thing I haven’t decided on yet, which is how to deal with combining a device preset with a multistream file.

The biggest blocker currently for finishing this work is that the GStreamer encodebin element does not have an API yet for dealing with selecting encoding settings for multiple streams as detailed in this bug report. If anyone got the inclination to cook up a patch for encodebin which adds support for this that would be much appreciated.

Anyway, once I have this completed I think my next step will be to try to add some kind of DVD ripping support to Transmageddon and some basic metadata checking/editing and move the video flipping support into a special menu and add support for enabling/disabling deinterlacing in that same special menu. I trying to figure out as I go along how I can keep the user interface simple and straightforward and add requested features. The question that I continuously ask myself is what features do belong in Transmageddon and what features are of a level where people should go to something like PiTiVi instead.

Improved handling of files with multiple tracks in GStreamer

Thanks to Sebastian Dröge there is a new thing in GStreamer called streamid. It basically gives all streams inside a given file a unique id, making files with multiple streams a lot easier to deal with. This streamid is also supported by the GStreamer discoverer object. So once you identified the contents of a file with discoverer you can be sure to grab the exact stream you want coming out of (uri)decodebin by checking the pad for the streamid. The most common usecase for this is of course files with multiple audio streams in different languages.

From the output of Discoverer the stream id is really easy to get:
On the stream object you get out of Discoverer you just run a:


On the pad you get from decodebin or uridecodebin the patch is a bit more convoluted, but not
to hard once you know how (there might be some kind of convenience API added for this at some point).

Before you connect the pad you get from the bin you attach a pad to it like this:

src_pad.add_probe(Gst.PadProbeType.EVENT_DOWNSTREAM, self.padprobe, None)

Then you in the function you define you can extract the stream_id with the parse_stream_start call as seen below:

def padprobe(self, pad, probeinfo, userdata):
       event = probeinfo.get_event()
       if eventtype==Gst.EventType.STREAM_START:
           streamid = event.parse_stream_start() 
       return Gst.PadProbeReturn.OK

I been using this code in my local copy of Transmageddon to start implementing support for files with multiple audio streams (also supporting multiple video streams would be easy, but I am not sure how useful it would be). Got a screenshot of my current development snapshot below, but I am still trying to figure out what would be a nice way to present it. The current setup will look quite crap if the incoming file got more than a few audio streams. Suggestions welcome :)

Transmageddon multistream  devshot
Transmageddon multistream development snapshot