All posts by uraeus

GStreamer

Dirac at the IBC

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So I am just back from the IBC conference in Amsterdam. Enjoyed it a lot and got to see a lot of interesting new technology. Especially the SuperHighDefinition demonstration was pretty nice, although I think we have to settle with 1080p in the home for the forseeable future.

One interesting thing I noted was that a lot of booths was using the Big Buck Bunny video to demonstrate their technology. The BBC did this at the Dirac booth for instance, but also a lot of other vendors used this clip. Which do not surprise me as apart from Big Buck Bunny being of good quality it is next to impossible to get permission by right holders to get access to any of their source material to create a version of a trailer for instance using a specific encoder or codec. Don’t want to name and shame anyone, but I have for instance tried multiple ties in getting one of the major Hollywood animation houses to let us create a Dirac version of one of their trailers. While I gotten positive feedback from my (technical) contacts for doing this, getting approval from management and marketing has so far eluded us.

But there is some irony in that at a conference where companies in the broadcasting industry show their goods, they end up using something produced by a group of people outside their industry as getting permission to use the content they create themselves is to hard :)  (That said I should point out that the BBC also showed of a clip of their Torchwood sci-fi in Dirac HD, so the BBC did also manage to get permission to use some of their own content.

Another example of how crazy the rights jungle can be was that NuMedia who was demonstrating their DiracPro hardware products at the show even had to just write ‘Dirac was used by BBC to transfer video from Bejing 2008’ in their material, explaining how the BBC had used Dirac for their intermedia data transfer for the Bejing Olympics. Using the word ‘Olympics’ in their material was something they where told was not allowed.

Dirac Big Buck Bunny movie playing in Totem:
Big Buck Bunny Dirac Totem

Oddball entries

Is the United States government solvent?

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When George Bush responded to the US downturn by sending everyone a check with some money my first thought was that it might not be the right approach to solve the current issues in the US economy. My reasoning is that I think that the main problem the US face at the movement is that the federal government is heavily underfunded and that the world markets are starting to doubt the strength of the US economy due to the extreme level of debt the US has acquired. So splashing out money to stimulate consumers might alleviate things a little in the short term, it made the underlying problem of US state finances being horrendous bigger. While this problem was not completely ignored by analysts at the time, it was mostly mentioned as a byline. In fact I think that if I hadn’t been searching for mentions of it I might have missed those mentions all together.

Got reminded of my worries today when I came accross an article in a Norwegian paper discussing the Fannie Mae and Freedie Mac bailouts. The US federal government having to bail out  Fannie Mae and Freddie Mac comes at the price of taking on even more debt at the federal level. And while I don’t doubt the need for the takeovers, I can’t help but wonder if by putting out one fire they have laid the foundation for a bigger one. The US defaulting on its debt would have rather overwhelming negative consequences for the world economy. And if that article is correct I am not alone in my worries, it seems a lot of the Asian countries which has up to know invested their trade surpluses into US bonds are getting cold feet and have started pulling out.

GStreamer, Patents and Copyright

Stephen Fry on FSF anniversary

Just noticed today that the FSF managed to get Stephen Fry to make a video in celebration of the 25th Anniversary of the FSF. Been a fan of Stephen for a long time, ever since I first saw him in Blackadder many years ago, so it is cool to see him doing this sort of promo for free software. Been aware that Stephen Fry has advocated free software in his blog for some time, but it is still nice to see such direct interaction with the community. The video is available in Ogg format using Theora video and Vorbis audio, which also makes me happy. I even ended up emailing them saying I be happy to convert their source material into a HD Dirac+Vorbis version if they are interested. Every time I see stuff being published in free formats it makes me feel very good about the work we are doing here at Collabora and the goals we have set for ourselves.

Dirac Everywhere

On the topic of Dirac there are a lot of fun stuff happening. One thing I failed to mention before, is that there is a Dirac Quicktime component available now. Still alpha quality, but part of the effort done to reach out to a wide a community as possible with Dirac. There has also been work happening on wider Dirac support in GStreamer and integrating that support better into GStreamer. For instance Thiago merged a patch from David Schleef to add Dirac support to the new quicktime muxer Thiago created as part of the summer of code. It already works well, but we need to do a little Pitivi hacking to enable it there. Edward hopes to get at that before the weekend. Finally Sebastian Dröge merged the transport stream muxer library and plugin into gst-plugins-bad, which also can mux Dirac video (the library used to be hosted on the old Dirac website). Sebastian will also be working on making sure that muxer can create some Playstation 3 friendly files going forward.

Also thanks to Fluendo and Zaheer we know have a working transport stream demuxer in gst-plugins-bad which of course also handles Dirac.

Centralising GStreamer plugins

On the back of this I think we will try to do a bigger effort to merge some of the external plugin repositories into GStreamer proper. For instance at Collabora we got the gst-plugins-farsight module which should have its plugins moved over. Our latest team member Mark Nauwelaerts got his GEntrans plugins which should also move over. Having a central set of repositories and plugins makes them easier to find for everyone and will also increase the ease of maintenance. And of course reduce the risk of people doing something which someone else has already done.

GStreamer

GStreamer Quicktime Muxing

So the official part of the summer of code is now over. I am sure the mentors will blog about the results in general, but since I have followed the Quicktime muxing project the closest myself and since Wim do not have a blog I thought it would be nice to give it a mention. Quicktime is a quite complicated format, orignally created with both editing in use, but also tied quiet closely to the quicktime media framwork. It also has a lot of derivatives like the MPEG4 container format and the 3GPP mobile container format. So when writing a muxer one need to take into account that the user might want a muxed file conforming to any of those 3 standards.

Anyway, Thiago Sousa Santos has been working hard over the summer and we now have the basic muxer working. With the baseline in place there are of course a lot of small details that needs to be taken care of, like adding support for all the different codecs which can go into a Qt/MP4/3GPP container format for instance. Thiego is well underway with that effort already though with h264 support added just a few days ago (I found a bug in the muxer testing it though, but I am sure we will sort that out quick enough). Other codecs we would want to support soon would be Dirac in Quicktime for instance.

The code is not yet in GStreamer CVS, but currently hosted in this SVN repository. But with the Summer of Code over I guess we can look into moving it into the main GStreamer repo. The great thing is that Thiego will continue working on the muxer even though the Summer of Code project period is over so hopefully all GStreamer users will have a top notch Quicktime/mp4/3gpp muxer to use once all major media formats are supported and tested.

So I would like to congratulate Thiego on having completed this years Google Summer of Code project in a absolutely brilliant way and thank him for the effort so far. The future looks bright!

General, Oddball entries

GUADEC photos online

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I have been looking for a new hosting option for a while and last week I finally choose one. Based on recommendations from others I ended up going with Slicehost. Slicehost advertise themselves as being a hosting company for developers, which I learned is definitely true. It is the first time ever I had a hosting setup where I even needed to install and configure my own email server. Learned a lot about Postfix over the last weekend :)

That said their setup is pretty nice. You can choose which linux distro you prefer from a quite big list and they will automatically set up your slice with that distro for you. They also have nice webtools for configuring things like DNS. And finally they got a lot of easy to follow tutorials on how to get common server tasks configured and running. Most of them Ubuntu centric, but I found it easy enough to find the Fedora equivalents when needed.

Once the basics was taken care of it was time for me to get my photo gallery back online after a longer period of being offline. Mostly due to me not having kept the gallery code up-to-date (and thus secure) it had been disabled at my old hosting provider. So upgrading to latest version was step one. The upgrade instructions turned out to not work at all, but doing a fresh install seemed to do the upgrade job just as well, it still managed to pick up all my old photos. I am still using Gallery 1.x though, but I noticed that Fedora packages Gallery 2. So I should probably switch to that at some point as having Fedora packagers make sure I am up to date without glaring security holes is more likely to work in the long run.

Anyway, to summarize a long story, my photos from GUADEC are now online :)

I also orderd myself an Epson 350 photo scanner today after discovering that <a href=”http://avasys.jp/hp/menu000000500/hpg000000442.htm”>Epson</a> actually provides official drivers for Linux. Hopefully I will soon also get all my pre-digital photos online.

GNOME, GStreamer, Patents and Copyright

How to mix code with different licenses

Got a question on IRC today about the licensing of a specific file in GStreamer CVS, as it was under a MIT license instead of the LGPL license. While we strive to keep our licensing simple by making all new code LGPL or in some specific cases dual licensed, there are a few cases where we got code which is under the MIT or BSD license. This create a situation where we have some files in a directory under the LGPL while others are MIT for example. While I think he have kept things on an even keel within GStreamer, I have noticed that there is a lot of confusion in the open source community in general, about how you deal with MIT and BSD code in a GPL/LGPL context. In some extreme cases I have even seen people just cut’n pasting the MIT code into their GPL project believing that the MIT ‘do what you want license’ includes the right to relicense the code. It does not.

Anyway, to clear up the details for myself I contacted Luis Villa to get some help understanding some of the possible corner cases. Luis then pointed me at this great resource from the Software Freedom Law Center for understanding how MIT and GPL code can co-exist in your codebase. I absolutely recommend reading over this to better understand the implications.

GNOME, GStreamer

cdparanoia now LGPL v2

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Some time ago I blogged about cdparanoia switching from GPLv2 to LGPLv3 on our request. After that time we have been discussing in the GStreamer community about licensing and what is the exact and implicit licensing promise we are and have been making with GStreamer. The conclusion was that since the LGPLv3 is more restrictive than the LGPLv2 we do not want LGPLv3 dependencies in gst-plugins-good and gst-plugins-base. As mentioned before we always tried to be very serious and coherent with our licensing in GStreamer and suddenly reducing the rights we offer application and plugin developers is not something we feel should be done without very good reason. This is a policy I hope also other important libraries decide to follow, personally I would think it would be a very sad thing if Glib and Gtk+ for instance started taking away rights from their users without a very well reasoned explanation.

Luckily Monty is a very kind soul, and starting from yesterday there is a new version of cdparanoia III out, 10.1, which is dual-licensed under the LGPLv2 and the GPLv2. So even in the future there will be cdripping support offered in GStreamer gst-plugins-base package.
So go to the cdparanoia download page and get yourself this minty fresh version of cdparanoia. We recommend distributions to update to this version as soon as possible to ensure there are no licensing conflicts in their distribution.

General, GNOME

Twins

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I was watching The Daily Show yesterday and Seth Rogen was on as the guest. For those who doesn’t know him, he is a comedian who has starred in movies such as Superbad, Knocked up, Pineapple Express and the upcoming Kevin Smith movie ‘Zack and Miri Make a Porno’. Anyway when listening to him it struck me that I had heard that exact voice and accent somewhere else recently. Then it struck me, vocally Seth Rogen and our own Luis Villa are identical twins. So if you are doing a podcast and Luis is not available for an interview take comfort in knowing you can hire Seth Rogen to do the interview instead and nobody will know the difference.

General

GStreamer’s new deinterlace plugin

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One of the tasks we gave Sebastian Dröge when he joined us here at Collabora Multimedia was to make sure we had a decent deinterlacer plugin in GStreamer. There had been a plugin in bugzilla for quite some time which contained some code culled mostly from the tvtime application by Billy Biggs. I had spent quite some effort back in the day tracking down the needed people to relicense that code to the LGPL, but it still needed quite some work to be functional. Sebastian has been cleaning up the code and also ported all assembly code in there to C so that it works on all platforms (the assembly code is still in place for relevant platforms). The code for this ‘deinterlace2’ plugin is in gst-plugins-bad currently where Sebastian is fixing up the last niggling issues. But for the adventurous the code can be grabbed from CVS. Below are two screenshots showing a interlaced video with and without the use of the deinterlace2 plugin.

So here is a screenshot using a playback pipeline with the deinterlacer plugin inserted:
gst-launch filesrc location=clip.vob ! decodebin2 ! ffmpegcolorspace ! deinterlace2 ! xvimagesink

Deinterlaced

And here is the same clip using a pipeline without the deinterlacer:
gst-launch filesrc location=clip.vob ! decodebin2 ! ffmpegcolorspace ! xvimagesink
Interlaced

The clip isn’t of the best quality to begin with, but it was the only one I found with interlacing on my disk. But if you click in and look at the two pictures you do very clearly notice the interlacing creating a jagged look of the second image.

This new improved deinterlacer should be very useful for some DVD’s and DVB transmissions, so once we get this fully integrated both DVD watching and DVB watching in Totem should be a very nice experience.