Category Archives: GNOME

Summary of GStreamer Hackfest

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So as I talked about in my last blog post we had a great GStreamer hackfest. A lot of things got done and quite a few applications got an initial port over to 0.11. For instance Edward Hervey ended up working on porting the Totem video player, or rather trying to come up with a more optimized design for the Clutter-gst as the basis port was already done.

Another cool effort was by Philippe Normand from Igalia who put a lot of effort into porting WebKit to use 0.11. His efforts where rewarded with success as you can see in this screenshot.

Jonathan Matthew had flown up all the way from Australia and made great progress in porting Rhythmbox over to the 0.11 API, a port which became hugely more useful after Wim Taymans and Tim-Phillip Muller fixed a bug that caused mp3 playback not to work :).

Peteris Krisjanis made huge strides in porting Jokosher to 0.11. Although like Jason DeRose from Novacut and myself on Transmageddon he did end up spending a lot of time on debugging issues related to gobject-introspection. The challenge for non-C applications like Jokosher, Novacut, Transmageddon and PiTiVi is a combination of the API having changed quite significantly due to the switch to gobject-introspection generated bindings, some general immaturity challenges with the gobject-introspection library and finally missing or wrong annotations in the GStreamer codebase. So once all these issues are sorted things should look a lot brighter for language bindings, but as we discovered there is a lot of heavy lifting to get there. For instance I thought I had Transmageddon running quite smoothly before I suddenly triggered this gobject-introspection bug.

There was a lot of activity around PiTiVi too, with Jean-François Fortin Tam, Thibault Saunier and Antigoni Papantoni working hard on porting PiTiVi to 0.11 and the GStreamer Editing Services library. And knowing Jean-François Fortin I am sure there will soon be a blog with a lot more details about that :).

Thomas Vander Stichele, who also wrote a nice blog entry about the event, was working with Andoni Morales Alastruey, both from Flumotion, on porting Flumotion to 0.11, but due to some of the plugins needed not having been ported yet most of their effort ended up being on porting the needed plugins in GStreamer and not so much application porting, but for those of you using plugins such as multifdsink, this effort will be of great value and Andoni also got started on porting some of the non-linux plugins, like the directsoundsink for Windows.

Josep Torra from Fluendo ended up working with Edward Hervey on hammering out the design for the clutter-gst sink at the conference, but he also found some time to do a port of his nice little tuner tool as you can see from the screenshot below.

Tuner tool for GStreamer 0.11

George Kiagiadakis kept hammering away at the qtGStreamer bindings, working both on a new release of the bindings for the GStreamer 0.10 series, but also some preparatory work for 0.11.

In addition to the application work, Wim Taymans, Tim-Phillip Müller and Sebastian Dröge from Collabora did a lot of core GStreamer clean ups and improvements in addition to providing a lot of assistance, bugfixing and advice for the people doing application porting. All critical items are now sorted in 0.11 although there are some nice to have’s still on the radar, and Wim plans on putting out some new releases next week, to kickstart the countdown to the first 1.0 release.

As for my own little pet project Transmageddon, it is quite far along now, with both manually configured re-encodes and profile re-encodes working. Still debugging remuxing though and I am also waiting for the deinterlacer to get ported to re-enable deinterlacing in the new version. For a screenshot take a look at the one I posted in my previous blogpost.

GStreamer Hackfest in Malaga update

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Things have been going really well here at the GStreamer Hackfest in Malaga. Thanks to the help of Ara and Yaiza from Nido Malaga, we have a great venue in downtown Malaga and they have also helped us greatly with sorting out food.
We have a great group of people here and are making great progress, and by tomorrow I hope we will have screenshots of quite a few applications running with GStreamer 0.11, for instance both Rhythmbox and Jokosher for instance is already screen shootable, if not fully functional :)

GStreamer Hackfest Malaga 2012

GStreamer Hackfest Malaga 2012

Also making good progress on Transmageddon, even if the move to GObject Introspection bindings are making things a bit more complicated. Screenshot below of the progress so far.

Transmageddon at Hackfest in Malaga 2012

Transmageddon at Hackfest in Malaga 2012

Also a big thanks to Fluendo who is sponsoring the lunches at the hackfest and Collabora who is sponsoring tonight’s dinner. Ensuring that no hacker is left hungry during this hackfest.

Update: Yaiza took these photos from the hackfest

Interview with Arun Raghavan about PulseAudio

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With all the talk generated by Arun Raghavans blog post comparing PulseAudio and Audioflinger I thought it would be good to follow up with an interview with Arun about the latest developments in PulseAudio and the way forward for the project. You can find the PulseAudio interview here. I also made a new page listing all the Collabora developer interviews done so far. Enjoy :)

GStreamer Hackfest in Malaga

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Tomorrow I will be heading off to attend the GStreamer Application Porting Hackfest in Malaga, Spain. I think we have managed to pull together an absolutely incredible group of people for this event and I have great hopes that by next weekend we will have squashed a ton of bugs in GStreamer 0.11/1.0 and also have initial ports of a long range of important applications and bindings. This is the first time in GStreamer history that we are trying to hold a hackfest focused on application developers, but hopefully it will be the first of many and that they can become a good way for the core GStreamer community and the application development community to interact and collaborate more closely.

Also want to say a special thanks to the community members attending the event on their own and also to the companies sending their employees to the hackfest; Collabora, Fluendo, Flumotion and Igalia and finally a special thanks to the GNOME Foundation for sponsoring some of the attendees.

Hopefully I will be able to post some screenshots of a fully functional GStreamer 1.0 Transmageddon next weekend :)

Transmageddon runs with GStreamer 0.11

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After updating GStreamer and doing a couple of small fixes I managed to make Transmageddon work with the GTK3 and the 0.11 branch of GStreamer. Obligatory screenshot below. As you might guess from looking at the screenshot there are still some issues that needs solving, but
I am happy that I managed to get this far.

Screenshot of development Transmageddon

Transmageddon running GTK3 and GStreamer 0.11/1.0

Hopefully it is a sign that the upcoming GStreamer hackfest in Malaga will be a great successful everyone who is participating.

I hope the remainder of the porting effort will be relatively simple as I would love to get back to working on real features instead of just updating old functionality to use a new backend to do the same. Having had a need for Transmageddon for a couple of work related tasks recently a couple of items, like batch job programming has moved up my priorities list.

GStreamer 1.0 Application porting hackfest/code sprint

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We are trying to put together a hackfest to help developers using GStreamer to port their applications to GStreamer 1.0. The GStreamer Hackfest/Code Sprint 2012 will take place in Malaga, Spain, between 25th to 27th of January (3 full days). I would ask all developers out there interested in attending to add your name to the wiki as quickly as possible, just so we can estimate interest. If you are interested, but don’t know for sure if you can make it there, it would still be good if you added your name with maybe a comment mentioning that you need to verify before you are certain.

We will be offering some travel sponsorship, so even if you are short on cash we hope to have you attend, more details on the hackfest&codesprint wiki page.

For those wondering why we choose Malaga, well the reason is that Wim Taymans, the GStreamer 1.0 designer and lead developer lives there, and at a previous hackfest we tried to do in Oslo he ended up in Helsinki instead. So this time we are taking no risks, but instead we are taking the hackfest to him :)

Farstream and libnice, an interview with Youness Alaoui

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After the success of the GStreamer interview with Wim Taymans I thought we follow up with another great interview with a Collabora developer.

This time we are talking with Youness Alaoui who is one of the maintainers of Farstream, the audio and video conferencing framework built on top of GStreamer. We also cover another of Youness Alaoui projects, libnice, the NAT traversal library. So if you want to know what is happening with audio and video conferencing on Linux be sure to read the full interview with Youness Alaoui here.

Transmageddon 0.20 released

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So after a very long 1 year development cycle I finally managed to push a new release of Transmageddon. The main reason for it haven taken this long was because I decided to port to the brand new discoverer and encodebin elements, to greatly simplify the code and improve functionality. The thing was that Edward Hervey when he wrote those elements took the conscious decision to make them assume that all needed GStreamer plugins worked as they should to be perfect GStreamer citizens. As you might imagine, since many of the plugins had never been tested for all such behaviour a lot of things did not work after the port. But over the last Months I have filed bug reports and most of them are now fixed. And with todays new python-gstreamer release (0.10.22) the fix for the binding bug for encodebin is fixed and thus I decided it was time to put out a new release.

I am quite happy with my new feature list:

  • Port to new plugins-base discoverer and encodebin
  • Replace radiobutton lists with a combobox instead
  • add support for audio only transcoding
  • add support for outputting audio only from video+audio files
  • Add deinterlacing
  • Support container free audio formats such as FLAC, mp3 and AAC
  • Add HTML5 and Nokia 900 profile
  • add support for video only transcoding
  • add support for mpeg1 video and mpeg2 audio

The new user interface should solve the problems people with small screens used to have with Transmageddon, like many netbook users. Transmageddon now also automatically deinterlaces deinterlaced video clips, I want to improve this feature in a later release, but making it optional to deinterlace and also use Robert Swains new elements that can help detect interlaced files that have been encoded as progressive files (as shown in his presentation in Prague).

Another major feature of this release is that audio only files are now officially supported, and you can also use Transmageddon to easily output just the audio from a audio+video clip.

I also added a HTML5 webm profile, so output to that should be easier than ever. In fact I used that profile when I transcoded 100GB of video that we had recorded at an internal session at Collabora.

My next goal is to port to GStreamer 1.0 and GTK3. That said if there turns out to be some brown paper bag issues in this release I will try to fix them and make a new release, but my guess is that most bugs people might encounter will be because there are issues that are only fixed in GStreamer git yet, so until they are all released not everything works 100% and until those releases are out there might be some small regressions from the previous release.

Anyway, I hope you head over to the Transmageddon website and grab the latest release for a test run. I will try to follow-up on bug reports, but might be a bit slow the next week as I am flying down to Lahore to celebrate my sister-in-laws wedding and also see my beautiful wife again after almost a Month apart.

Dynamic Adaptive Streaming over HTTP standard, ST Microelectronics, Fraunhofer and GStreamer

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Edward Hervey pointed out to me this morning that there are some nice articles online about an effort between ST Microelectronics and Frauenhofer, around the 3GP DASH (Dynamic Adaptive Streaming over HTTP) standard. There is for instance this article in Thinq magazine and this article on TMCnet. What you might not know and which is even cooler is that Emanuele Quacchio will be speaking this GStreamer based DASH implementation at the the GStreamer Conference later this Month. So if you haven’t signed up for the GStreamer Conference already, then maybe this is the time to do it :)

I am really excited about this years GStreamer Conference as we have a lot of ongoing efforts about to come to fruits. From Collabora we got Wim Taymans will be talking about GStreamer 1.0 effort, which we expect to have out before years end and Tim-Philipp Müller will speak about a lot of the other incredible advances we made over the last year. Being in the middle of it I think its easy to go a bit blind due to the gradual process, but things like the new parsing libraries that Thibault Saunier have been working on, which will enable much quicker and better support for things like libva and vdpau plugins in GStreamer. Or the new baseclasses that Mark Nauwelaerts have ported most of our plugins over to now, which in one fell swoop improved our plugin quality by leaps and bounds. And of course there are things like the GStreamer Editing services (GES), discoverer and encodebin which Edward Hervey created, which will make applications like Transmageddon video transcoder and remuxer and the PiTiVi video editor a lot easier to develop.

We will also be doing some real cool demonstrations of stuff we have been working on at Collabora at the Linux Con Showcase on Thursday. Thanks to GES we have a great demo of a mobile editing solution using either QML or HTML5. We have HTML5 video calling using Telepathy and we have Video calling using Telepathy from the Media explorer media center solution.

Another talk that I will be sure not to miss is Jan Schmidt who will be talking about Blu-Ray playback with GStreamer. In addition to being technically interesting Jans talks are always fun, like last year he did his presentation using GStreamer instead of something like LibreOffice, having created his slides as a DVD menu through a small program he wrote to turn SVG files into DVD menus :)