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Interview With BBC Dirac Developer Thomas Davis

arclightfire writes "The subject of the BBC video codec Dirac has been here before, but we've managed to get an interview with Thomas Davies, Senior R&D Engineer at the BBC who devised the Dirac algorithm. Interesting to note that the codec should be with Mplayer soon; "As far as players go, we'll be submitting a patch to Mplayer to allow it to play Dirac pretty soon." And info about the tech developments in Dirac; "I used tried and techniques, like wavelets, which weren't in standards at the time, and tried to develop them. And that's what we'll continue to do as the algorithm develops. So we've tried to build on some pretty well-understood technology, and also tried to do some new things with it. We're patenting the new stuff, quite a bit of which hasn't got into the software yet. The license means that these patents are licensed for free within the Dirac software.""

47 of 170 comments (clear)

  1. Great codec, awful name by YetAnotherName · · Score: 3, Funny

    Especially from a British developer ... I mean, he could've gone with something like "The Cybermen Codec" or "The Sontaran Codec" or at least "The Dalek Codec" ...

    1. Re:Great codec, awful name by savagedome · · Score: 2, Funny

      I would definitely take a suggestion for name from somebody whose id is "YetAnotherName". Yup.

    2. Re:Great codec, awful name by AKAImBatman · · Score: 2, Funny

      "Always Look on the Bright Side of the Screen"

    3. Re:Great codec, awful name by Fallen+Andy · · Score: 5, Interesting

      Oh boy. You *are* ignorant. "Dirac" is the physicist
      who came up with the idea of anti-matter. Not only that but he did his Bsc at Bristol University. Yeah
      Bristol south-west of england.

      He didn't like it though. Don't know why, worked for
      me (splutters). I escaped that fine institution as
      a chemist (but I have spent far too many years playing with computers...).

      Bristol is also where the BBC has some of it's more
      interesting people, like the wildlife unit.

      Oh and Bristol Zoo. Which thanks to Alan Cox (cheers mate) used to have a penguin called Linus.
      If I wasn't stuck here in Rainy Athens (hey? I'm
      winding up the UK people ok..) I'd go kiss it right now.

  2. Dirac's not the only new codec in the running by Frac · · Score: 5, Informative

    h.264 (now formally known as AVC, the video-equivalent of AAC) is maturing. Well, at least Ahead's Nero Digital implementation of h.264 is maturing. The marketing spin has it called Nero Digital, but it's fully h.264 compliant. And the results are impressive - beta testing shows comparable quality of XviD at half the bitrate.

  3. Why bother? by JPyObjC+Dude · · Score: 5, Informative

    H.264/AVC is open and extremely powerful. Why bother with another protocol?

    From Apple Tiger h.264 page:
    Not only is H.264/AVC very efficient, providing extremely high quality in smaller files, but H.264/AVC is also scalable, producing video for everything from 3G for mobile phones to High Definition (HD). H.264/AVC can create great-looking 3G mobile content at 50-160 Kbps, excellent Standard Definition (SD) video at 800-1500 Kbps, beautiful HD video (1280x720, 24p) at 5-7 Mbps and full HD video (1920x1080, 24p) at 7-9 Mbps. So at today's SD DVD data rates, H.264/AVC can deliver full HD. In fact, H.264/AVC was ratified by the DVD Forum for inclusion in the next-generation HD DVD format.

    1. Re:Why bother? by damiam · · Score: 3, Insightful

      Open? So, can you use it commercially without a license fee?

      --
      It's hard to be religious when certain people are never incinerated by bolts of lightning.
  4. Re:For Linux? by lphuberdeau · · Score: 2, Informative

    RTFA

    They plan on releasing open source and submit a patch for mplayer themselves.

    --
    Qui ne va pas à la chasse n'a pas de gibier
    PHP Queb
  5. Is it in M*ENCODER* by strredwolf · · Score: 4, Interesting

    Having decode support in Mplayer is good. but it's not going to fly well if there's no support for encoding! How are you going to use it to it's full potential in Unix if you can't back up your DVD's with it?

    It goes double for the Ogg Theora format.

    --

    --
    # Canmephians for a better Linux Kernel
    $Stalag99{"URL"}="http://stalag99.net";
    1. Re:Is it in M*ENCODER* by diracvideo · · Score: 5, Informative

      Both a C interface to our encoder and direct show filters are on our road map. Monitor our site or check freshmeat to find out as soon as they arrive. Please bear in mind we are only in alpha.

  6. H.264 is pricey even more than MS's WMV 9 by riversky · · Score: 5, Informative

    The license costs on H.264 are the most expensive on the planet (MPEG LA controls it with a hell of a lot of patented stuff from various companies). This is why it isn't being adopted rapidly. Even MS undercut it with cheaper licensing on Windows Media. This will kill it, a very nice technology. I am all for open source codecs. Perhaps BBC is on to something.

  7. Why not use OGG Theora? by solidhen · · Score: 4, Interesting

    From what I've read it looks like the goal with Dirac is to get a royalty free codec. If this is correct then why did you decide against using/contributing to the open source/open standard ogg theora codec?

    --
    Some things are more important than an animated rat
    1. Re:Why not use OGG Theora? by 42forty-two42 · · Score: 2, Insightful

      If the quality of Dirac is higher it should of course be preferred. That said, I have not seen any video encoded with either, except for that Java Theora implementation last week (?), so I don't know which one is better.

  8. Re:No jokes about Wendys? by Resident+Maniac · · Score: 3, Funny
    No jokes about Wendys? What the hell, where are all the slashot humorists?
    In Soviet Russia, Wendy's jokes about Slashdot humorists! =P
    --
    "Life isn't about the number of breaths we take; it's about the moments that take our breath away. Like choking."
  9. Re:Dirac is free, H.264 is not by JPyObjC+Dude · · Score: 2, Interesting


    Licence snippet:


    In the case of the (a) encoder and decoder manufacturer sublicenses:
    For (a) (1) branded encoder and decoder products sold both to end users and on an OEM
    basis for incorporation into personal computers but not part of an operating system...




    I read that this applies to sold software not free software. Licence free for free (OS) software?

  10. Patents by Anonymous Coward · · Score: 3, Interesting

    Sounds like those patents are licensed for free within the context of this project, but not if you take the technology out of the codec. Fine, great, except that's the same license Microsoft offered on their SPF stuff, and they got drilled for it.

    1. Re:Patents by diracvideo · · Score: 4, Informative

      Dirac is licensed under the MPL (Mozilla) triple license. This means it is primariliy licensed under the MPL but anyone is free to re-license under either the GPL or LGPL licenses. We used the Mozilla license becuase it is well known and deals with patent issues. It means that any patents the BBC can license relating to the software are implicitly and irrevocably licensed for the software. So there are no royalties to pay for developing or using this software (either encoder or decoder). We chose this license to try to ensure that the codec remains royalty free. We figured if it was good enought for the Mozilla project it would probably be OK for us too. On the other hand we are aware that the MPL, on its own, is incompatible with the GPL and LGPL. We didn't want this and so have allowed re-licensing under the GPL. This means GPL software can freely integrate and develop Dirac. This is the approach suggested on the Gnu license page. You can also license Dirac under the LGPL. This means that even proprietary software can use it if they dynamically link with the libraries. The reason we have done this is so that the widest range of users can use Dirac royalty free.

  11. what? by squarefish · · Score: 3, Funny

    the BBC working with software?

    did they have anything to do with python?

    --
    Creationists are a lot like zombies. Slow, but powerful and numerous. And they all want to eat our brains.
    1. Re:what? by UserGoogol · · Score: 3, Funny

      Oh wow. I had absolutely no idea that there was once a comedy group named after the Python programming language. And in 1969! Those cats were ahead of their time.

      --
      "Never attribute to malice that which can be adequately explained by stupidity." -- Hanlon's Razor
  12. Re:Now... by Kumkwat · · Score: 2, Insightful



    Microsoft Research lives at Cambridge. They would be very interested in innovative compression techinques.

  13. Dang, now when they invent the FTL telephone... by argent · · Score: 5, Funny

    Dang, now when they invent the FTL telephone they won't be able to call it the Dirac Communicator, 'cos everyone will think it's some kind of MP3 player!

    Another SF classic (Cities in Flight) shot down by careless scientist types. Goldarn it!

  14. Re:US media won't use it by calculadoru · · Score: 2, Funny

    It's DIE-rac, not dih-RAC

    Sorry about that one then.
    I still don't think the US media will use it, because it rhymes with (the bizarre way they choose to pronounce) Iraq .

    --
    The power of accurate observation is commonly called cynicism by those who have not got it. -- G.B. Shaw
  15. openness is hardly a concern to mplayer developers by SuperBanana · · Score: 3, Insightful
    Dirac is free, H.264 is not

    Bullshit. Every MPEG standard implementor is -supposed- to pay royalties. But I don't see any projects which support mpeg video and audio- doing so. I also don't see anyone chasing them down for the royalties. The general consensus is that if you don't make money off it, nobody will chase you down for the royalties; they're happy with the revenue stream from commercial software.

    Further, if you bothered to read up, you'd note that there's a reference implementation with downloadable source code, and documents on the (ahem) ISO standard.

    Also, listening to someone complain about proprietary technology and "openness" being a hinderance is pretty funny in the context of Mplayer, considering that the developers distribute codec packs consisting of commercial software (specifically DLL files) they're -not allowed to distribute- from Microsoft, Real, Apple, Intel, and many others. Dozens of proprietary video and audio formats are included.

  16. "licensed for free within the Dirac software" by Papineau · · Score: 4, Interesting

    Does that mean the license does not extend to other usages (besides in Dirac)?

    This could be problematic to include in Mplayer, as Mplayer is licensed under the GPL, and IIRC, there's a patent clause (clause #4?) in the GPL saying something along the lines of "if you license your patent for use in a GPL software, the license extends to all software derived from the first one, not only that first one".

    Is this a correct reading of the situation?

    1. Re:"licensed for free within the Dirac software" by diracvideo · · Score: 2, Informative

      Dirac is licensed under the MPL (Mozilla) triple license. This means it is primariliy licensed under the MPL but anyone is free to re-license under either the GPL or LGPL licenses. We used the Mozilla license becuase it is well known and deals with patent issues. It means that any patents the BBC can license relating to the software are implicitly and irrevocably licensed for the software. So there are no royalties to pay for developing or using this software (either encoder or decoder). We chose this license to try to ensure that the codec remains royalty free. We figured if it was good enought for the Mozilla project it would probably be OK for us too. On the other hand we are aware that the MPL, on its own, is incompatible with the GPL and LGPL. We didn't want this and so have allowed re-licensing under the GPL. This means GPL software can freely integrate and develop Dirac. This is the approach suggested on the Gnu license page. You can also license Dirac under the LGPL. This means that even proprietary software can use it if they dynamically link with the libraries. The reason we have done this is so that the widest range of users can use Dirac royalty free.

  17. Re:Interesting... by mikael · · Score: 2, Interesting

    It's obvious from the article that they have their own research programmers (they have their own R&D department. I used to see adverts for inhouse graphics programmers).

    They also sponsor quite a bit of university research projects. Probably the most important just now is virtual studios and automatic classification of video clips (automatically convert a video stream into a text description).

    --
    Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
  18. Re:openness is hardly a concern to mplayer develop by RiffRafff · · Score: 2, Insightful

    Also, listening to someone complain about proprietary technology and "openness" being a hinderance is pretty funny in the context of Mplayer, considering that the developers distribute codec packs consisting of commercial software...

    Which is legal in Hungary. Welcome to the internet, son.

    I can't help but wonder just how YOU came to know about them, you being such an upstanding citizen and all. Hmmm?

    --
    "I might have made a tactical error in not going to a physician for 20 years." -- Warren Zevon
  19. BBC Commitment to Open Standards by alib001 · · Score: 3, Insightful
    TD: I think the BBC has always had a very strong commitment to Open Standards...

    Yeah... a Real strong commitment.

    There's a list of excuses for their audio streams here. (No, you may not: cue / rewind / download the stuff the license payers paid to produce.)

    Hopefully they'll sort out their copyright / rights management issues and delivery by the time dirac comes out. Frankly, it couldn't make things worse.

  20. What happened to BitTorrent plan? by peteryorke · · Score: 2, Interesting

    What happened to BitTorrent plan for delivery of all the BBC archives? Wasn't it in August 2003 of last year that the BBC said it was going to deliver all of it's audio and video archive via Bit Torrent? I want all my BBC content online for download. When's it gonna happen or is this just more BBC pie in the sky R&D fluff.

  21. Re:openness is hardly a concern to mplayer develop by Spy+Hunter · · Score: 3, Insightful

    Yeah, it's all fine for now. But building free software on a proprietary base will bite you in the ass in the long run (which is why we have the Debian project, but that's a topic for another time). Eventually someone will make a program that the MPEG people don't like (such as an easy converter to Dirac), and they will get sued into next week. Or, if the open-source codecs are sucessful and become the de-facto standard for multimedia, THEN they'll start being pricks about the royalties. The MPEG consortium can come in at any time they like and destroy any open-source project using their standards, or leech off their hard work by charging everybody royalties. I wouldn't work on a project that had that hanging over its head, even if the MPEG people have been okay so far.

    --
    main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}
  22. Re:openness is hardly a concern to mplayer develop by Srin+Tuar · · Score: 2, Insightful

    This is a very big problem: major distros cannot include mplayer because of potential patent suits.

    Just because noone has filed suit yet means nothing.

    If you want desktop linux to have a chance there have to be popular patent-free multimedia formats that it can use.

    There really is no point in promulgating any more mental-prison ware than strictly necessary. When new codecs are being developed, it only makes sense to throw your support behind the free ones when you have a choice.

    (iow, Dirac + ogg in an mkv container could save your soul ;P )

  23. but when.. by Turn-X+Alphonse · · Score: 2, Insightful

    Do we get a government based report looking into it and decicing it's a waste of the licence fee money then kill it?

    The BBC is funded by people paying a licence to watch TV in the UK (it is illegal not to have one and watch TV in your place of residences). Now 99% of these people arn't geeks and won't use a codec, why are they paying for it?

    --
    I like muppets.
    1. Re:but when.. by trewornan · · Score: 4, Insightful
      Now 99% of these people arn't geeks and won't use a codec, why are they paying for it?

      Because in the future they will be using it (or something like it) and if the BBC don't sort something out right now - in ten years time we'll all be needing Microsoft's permission to view what their PR department doesn't object to.

    2. Re:but when.. by Bertie · · Score: 3, Insightful

      It's all part of the BBC's remit. It was the BBC that developed NICAM, for instance. The BBC took it upon themselves to encourage the takeup of home computing by coming up with the spec for their own machine and recruiting Acorn to make it. Their Internet presence has been a major factor in getting the British population online - the BBC's websites are now among the most popular in the world. And they're currently at the forefront of the push to get digital TV into every home in the country through their Freeview set-top boxes.

  24. no. Here's why. by don.g · · Score: 2, Informative

    mencoder at present (AFAIK) only outputs AVI, a format which doesn't cope well with VBR.

    Until it supports the ogg bitstream format, you're not likely to see Vorbis audio support, let alone Theora.

    --
    Pretend that something especially witty is here. Thanks.
  25. Warez codecs are holding back free multimedia by Wesley+Felter · · Score: 2, Insightful

    You're completely right; such a lax attitude towards copyrights is a big barrier to the adoption of free (as in legally free) multimedia formats and software. Free software developers who don't respect Microsoft, Real, Apple, and Intel's copyrights shouldn't expect much in return.

    Given the Dirac developers' attitudes, I would expect them to be more likely to contribute to legal multimedia frameworks like GStreamer or Helix. Maybe the point of Dirac/Mplayer integration is popularity at any cost, in which case the cost will be a semi-underground existence.

    A reference implementation and ISO standard doesn't do me (or Fedora or Ubuntu etc.) much good; it's still patent-encumbered and thus not free.

  26. network television by Doc+Ruby · · Score: 5, Funny

    The BBC has an R&D department that builds video codecs. In the states, we've got PBS which makes a new muppet every 10 years, and ABCNNBCBS, which came up with projecting a yellow bar across the football scrimmage line in the 40 years since introducing color TV. That's why America is leading the media revolution!

    --

    --
    make install -not war

    1. Re:network television by Singletoned · · Score: 2, Insightful
      That R&D department (a black box which you pour money in and get cool toys out) is possible because of the £120 a year fee every household in the UK has to pay.

      Which is a good thing, let's be clear.

      The value for money we get is good, but is secondary to the fact that it means we can get intelligent and impartial television and radio. Our friends in the US have nothing remotely like Radio 3 or 4. (High-brow classical music and jazz played in full, not just the famous bits, and high-brow, impartial current affairs, drama and comedy). They don't even have any politically impartial major broadcasters.

      In America most major stations are heavily right-wing because they are all owned by rich people who, unsurprisingly, support the Republicans. We get at least half a chance of hearing things from a reasonably independent, though critical, source.

      Worth every penny if you ask me, and I don't even watch TV.

  27. Re:openness is hardly a concern to mplayer develop by Spoing · · Score: 3, Insightful
    1. Bullshit. Every MPEG standard implementor is -supposed- to pay royalties. But I don't see any projects which support mpeg video and audio- doing so. I also don't see anyone chasing them down for the royalties. The general consensus is that if you don't make money off it, nobody will chase you down for the royalties; they're happy with the revenue stream from commercial software.

    Good point. One for you: Do you think the BBC will have to pay royalties if they use H.264?

    --
    A firewall can not protect you from yourself. Turn off what you do not need. Do not use the firewall to do your work.
  28. Re:"legal in hungary" does not change anything by ncc74656 · · Score: 2, Informative
    Further- just because [MPlayer]'s legal in Hungary doesn't mean it is legal anywhere else- which is why mplayer isn't distributed with, for example, Debian. I don't believe it is, in fact, distributed with any major Linux distribution.

    There is a Gentoo ebuild for it. The MPlayer files (source and DLL packs) aren't hosted by any of the Gentoo mirrors, but are retrieved from the MPlayer website. The same applies to most software for which ebuilds exist, though. Source for GNU programs gets pulled from GNU mirrors, source for SourceForge-hosted projects gets pulled from SourceForge mirrors, etc. Whether you could call this state of affairs "distribution" is open to debate, I suppose. While what Gentoo provides directly is in a sense little more than instructions and a patchfile, installing MPlayer is no more difficult than installing Emacs or KDE.

    (It's worth mentioning that system-specific optimizations (-march=athlon-xp, or whatever) are disabled in the MPlayer ebuild, which goes against one of the main reasons people use Gentoo. With that said, it's behaved reasonably well IME.)

    --
    20 January 2017: the End of an Error.
  29. Re:mplayer is bloated and going nowhere by 0x0d0a · · Score: 3, Informative

    Who cares about mplayer support?

    Those of us who prefer our keyboard to our mouse. And other folks.

    It's bloated. On both linux and MacOS X, it consumes considerable CPU resources- and that's with the fancy interpolation it supposedly does turned off. My Powerbook G4, for example- mplayer consumes about 60% CPU, enough to bake my lap and turn on the fan after a while. VLC, on the other hand- needs about 20%, keeping my lap happy.

    You misconfigured it. This is, admittedly, not hard to do, but mplayer is the fastest of movie players if used correctly.

    Try using the following command: mplayer -vo xv -fs=yes moviename.

    Hmm, upon checking the manual, perhaps if Mac OS X lacks support for xv you should be using -vo quartz.

    Mplayer has been under "development" for several years. It hasn't seen any major or even minor feature additions. /me boggles.

    You've got to be joking. What about the latest ChangeLog?

    The user interface sucks, especially on OS X.

    Actually, mplayer has some kind of bitmapped interface, which I always compile out. I hate all of those damned bitmapped interfaces, the pseudo-VCR things. It has a CLI interface which is exactly the same on OS X as on the other platforms.

  30. Re:openness is hardly a concern to mplayer develop by blibbler · · Score: 4, Informative

    Sorry for the double post, but it needs to be formatted properly

    Dirac + ogg in an mkv container could save your soul

    I assume you mean Dirac + Vorbis in Matroska... Ogg is a container format like matroska... (what you said was akin to DivX + AVI in ASF :-p )
    On a related topic, Matroska is an unfortunate format to use. It is very inefficient, both in CPU time, and in overhead. My computer can play a 640x480 divx in an avi, but can't play a 512x384 divx in matroska. Additionally, matroska has a higher file overhead than asf or quicktime.
    Ogg is a good, basic format. It could be seen as a sturdy replacement for AVI. Matroska doesn't do anything beyond even the Quicktime format... and quicktime is vastly more efficient.

    Anyway, moving on from that rant. I agree strongly with your other points. If you have a choice between two, largely equivalent codecs, one is unencumbered by laws and one is, why would you choose to use the one that is. Sure you might not get sued straight away, or even for a year or two, but why bother with that risk at all?
    I am not particularly bothered with pirating certain commercial software, but if there is a free program that does everything I need, I will use that over a pirated of a commercial program. Why take the risk when there is another option?

  31. Re:openness is hardly a concern to mplayer develop by DrSkwid · · Score: 2, Insightful

    mencoder is a simple movie encoder, designed to encode MPlayer-playable movies to other MPlayer-playable formats. It encodes to DivX4, XviD, one of the libavcodec codecs and PCM/MP3/VBRMP3 audio in 1, 2 or 3 passes. Furthermore it has stream copying abilities, a powerful plugin system (crop, expand, flip, postprocess, rotate, scale, noise, rgb/yuv conversion) and more.

    --
    There are places where the networks are not touching,and there are places where they are-Boeing's Lori Gunter
  32. The FAQ states... by Kristoffer+Lunden · · Score: 2, Informative
    What about Ogg Theora?

    We're glad that it looks like Theora will reach beta soon. We think you can't have too many free codecs, but that the Open Source community also needs to continue to develop codecs with increasingly better performance. We also think there could be a good deal in Theora that we could use in Dirac, and we'd like to work with developers who've been closely involved in Theora. We intend to pack the Dirac elementary stream into MXF, which has lots of useful features. That doesn't preclude it packing into Ogg as well, and it's probably a good idea to have a variety of packing formats. For this the elementary stream needs to be very well defined.

    http://www.bbc.co.uk/rd/projects/dirac/documentati on/faq.htm#11
    1. Re:The FAQ states... by dolmen.fr · · Score: 2, Informative

      For those who, like me, wanted to know more about MXF, it is the Material eXchange Format (and not "Multimedia Exchange Format" as Thomas Davies said in the interview).

  33. when a licence is needed (& good for Dirac!) by feepcreature · · Score: 2, Informative
    No it isn't, it's illegal to watch the BBC without paying for it. If all you use your television for is console games or other channels, don't tune your television in to receive BBC channels and you will be fine.
    The actual rule is that if you operate equipment that is capable of receiving broadcast TV signals you need a licence (UK spelling :-) ), or you have to license it. Even if you only watch commercial TV, or you never turn it on, or you only watch videos or play games (honest, guv).

    There are minor exceptions for small, battery-only devices in caravans, and the like, and people have escaped where they could show that they could not receive broadcasts (like there was no aerial for their TV/Video, and neither were tuned in to TV channels), but it's not easy.

    And the rules on multiple-occupancy are complex, and the way the BBC seeks to apply them seems to evolve. But the basic idea is that you need a licence if there are any tellies in a house.

    It's enforced by automatic reminders, detector vans, £1000 fines (Grand if you have a licence, a grand if you don't), and TV sellers notifying the authorities when they sell a telly.

    In my opinion it's great value, though. Even if it is being dumbed down, and the free internet-accessible archive seems to have stalled somewhere...

    But developing a codec is sensible if it keeps the costs of streaming down - and especially if it's easier to implement on Open Source O/Ss. Hopefully some penny-driven accounting type at the Beeb won't feel the need to charge huge licence fees or impose Open-Source-incompatible licence terms.

    --
    Paul "Say no to feeping creaturism"
  34. Re:Interesting... by mikael · · Score: 2, Funny

    That's the easy bit :)

    Your mission, if you decide to accept it, is to catalogue 80,000 hours worth of pixel colours in movies and video so it can be searched by location, actors, presenters, producer, camera operator, sound operator, objects, clothes, sky, clouds, landmarks, time, direction, events, astronomical, geological, geopolitical events, age and anything else that a producer may want on a whim at 5.30pm, 30 minutes prior to presenting the evening news.

    --
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