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Dirac: BBC Open Source Video Codec
NickFitz writes "Need To Know this week has a piece about Dirac, a BBC R&D project to produce a video codec, which has been released as an Open Source project. From BBCi: 'Dirac is a general-purpose video codec aimed at resolutions from QCIF (180x144) to HDTV (1920x1080) progressive or interlaced... Our algorithm seems to give a two-fold reduction in bit rate over MPEG-2 for high definition video (e.g. 1920x1080 pixels), its original target application. It has been further developed to optimise it for internet streaming resolutions.'"
right now I have good quality with 3vix but it is 1 gig.
if this can get me to 700 MBs at the same quality (about 85 in the 3vix) that would rock!!!
I am the Alpha and the Omega-3
True... just give me one free and powerful codec and I'll be happy... Can't we just have a standard here?
After 3 days without programming, life becomes meaningless
- The Tao of Programming
Hopefully the BBC will use this instead of RAM, silly real player!
I spent ages trying to think of sig, but never did
Could this be related to the archive of video content they are purported to be setting up? Seems like a very unnessecary step to accomplish that, unless they have some sort of conflict with the legalaties of other codecs out there...
Their documentaries are so interesting that I often choose to watch them over other movies or shows I may have on my computer. Bravo BBC.
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It's wavelet based, so presumably it doesn't suffer from the block artifacts of MPEG-2 & MPRG-4.
Even more impressive than the codec itself, in my opinion, is that they managed to develop a new video codec without infringing any patents! And given that it's the BBC, I assume they could go to court to defend themselves in prior art.
:-)
Very cool. But then all the engineers in their R&D dept. are apparently very anti software patents, and have been doing their bit writing letters to that effect
Did you ever consider that they intend to use this for their plans to put their archives online?
The poster stated that "It has been further developed to optimise it for internet streaming resolutions" which is one way for such a thing to be distributed. Have a look here. The register states that "The BBC's new media director, Ashley Highfield, said that a P2P network will allow the BBC to handle the volume of traffic it expects when the Internet Media Player (IMP) goes live. The IMP will enable users to download or stream content to their PC, laptop or palmtop computer."
If this is the case then Aunty Beeb is well underway to providing the tools we will need for accessing their archives.
-- Enditallnow
This is really wonderful news. The BBC is sharing its work with the Open Source community - and most of the British Open Source community are BBC TV licence payers.
I am glad that the BBC has recognised the need for this codec to be Open Source. It means that everyone, not just those beholden to private corporations, will get the chance to experience BBC content. The BBC is also a highly influential body; I would be surprised if other European content providers did not display an interest in this. PAL was a joint development between the BBC and its German counterpart; SUSE is German.
This is going to be one to watch.
Je fume. Tu fumes. Nous fûmes!
What do companies do when they have products which, though not being best of breed, require huge and increasingly unjustifiable Research and Development funds? They go Open Source! (no, I am not naming names... sap db netscape interbase ...
I mean all the BBC's services in general. I think I know the answer in assuming that the British people pay for it in tax and TV license fees. That's something I'm grateful for as a New Zealander living in the US. The BBC is a refreshing change to the somewhat mind numbing American news sources.
/. I definitely want on of those beside my bed when it becomes available. It seems like its the ideal thing for BBC listeners. I wonder if its availbility will significantly increase the load on their servers, all costing real money of course.
My real question to Brits here is: How well is this burden accepted by the British people? Are the BBC TV and radio stations in the UK really non-commercial? I know the US government gives money to PBS and NPR but I don't know how it compares (especially per capita) to what the British government must spend on the BBC. It must cost a fortune and they are effectively supplying (IMHO) a good quality product for free to the rest of the world via internet and shortwave. I imagine some of the international motivation of the BBC stems back to the days of the old empire. It almost seems too good to be true.
I assume that NPR and others like it around the world pay to carry the program. Maybe that earns a lot.
This question came up in my mind the other day when the wi-fi radio was mentoned here on
That's interesting. When I visited the R and D centre, they said that WMP streaming had a royalty model which they didn't like. They prefered Real's and gave no hint that they'll be doing WMP soon, but rather concentrate on Dirac. This is of course in an informal demonstration/chat, not official information.
I know that the BBC is somewhat of an enigma in broadcasting compared to what we're used to in North America (although some would argue networks like PBS and the Canadian Broadcasting Corporation are somewhat similar)....but I can't help think how utterly cool it is the BBC does this sort of thing. Progressive (no pun intended) stuff like putting their achives online is also really damn cool...not to mention the fact they have *gobs* of content that a traditional broadcaster wouldn't have (I've been taking Welsh language lessons courtesy of the BBC!).
-psy
Let's say you compare
a) 640x360 vid at 1x bandwidth
b) 640x360 vid at 9x bandwidth
c) 1920x1080 vid at 9x bandwidth
a) and c), MPEG4 will win. b) will be much much closer. What you define as "low" bitrates really depends on resolution. The dual-layer DVDs coming now should be able to do full HDTV resolution with somewhat better quality than a 1CD DVDrip. Since 2CD rips typically use 3-400mb on AC3 track, actually not that far away from 2CD rip. But something like 8-10Mbit (aren't they usually 1Mbit today?) is hardly a low-bitrate stream in my opinion...
Kjella
Live today, because you never know what tomorrow brings
I was fortunate enough to speak to a BBC employee about the codec at the Linux User & Developer Expo in London.
For one, MXF and AFF are two wrappers for convential video codecs, which add invaluable meta data to the file.
Dirac stands out as being a unique codec as it concentrates wavlets, motion compensation and arithmetic coding. This is not your standard codec.
Theora would be nice, but it's perpetually Alpha... I was excited about it at first too, but now it seems it's going to take another year before the code is even in beta, and probably two years before it reaches 1.0, when there will be ports to non-Linux platforms.
I wish Theora would move faster myself. I know nothing about codecs, but might try to find out how I can contribute.
By then, it will be about as advanced as MPEG-1 is today... Way behind the times.
Xiph has a project to develop an advanced codec called Tarkin. From the Theora FAQ:
It's a pity one doesn't hear about Tarkin more often, it seems more interesting than Theora, if more fanciful and unrealistic for current needs.
They also said that while they had no objection to paying licensing fee's per se, and that they did pay MS and Real, these were so inflexible in their licencing that scaling up operations was problematic. Their expressed hope was that with such a codec widely adopted they could massively scale up operations such as streaming without being crippled with licencing costs, or having the administrative burden of unwieldy licensing schemes.
-he who laughs last, is a bit slow.
journal
A matter of disclaimer: I've done some work on Dirac, for BBC, over the last several months. Here's a bit of background on Dirac:
By nature, Dirac has many similarities to existing algorithms such and MPEG-2 and H.264/AVC -- however, Dirac is an original invention that uses wavelet transforms, arithmetic encoding, rate-distortion optimization, variable block-size motion compensation, and hierarchical motion estimation in some new and unique ways. Again, this is a research project, so there's much experimentation to be done!
As a research project, Dirac continues to be analyzed, optimized, and documented. What you're seeing now is very preliminary code; I suspect it will improve and evolve dramatically in the coming months, both in terms of clarity and functionality. The goal is to produce a universal codec, which is one reason behind the open source move.
The codec source code is licensed under dual MPL/GPL licenses.
Dirac is modular, and thus well-suited to implementation with an object-oriented programming language. The reference engine is written in ISO Standard C++, and has been tested under various forms of 32- and 64-bit Linux, as well as under Windows 2000/XP.
I'll try to answer questions here, to the best of my ability.
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We have a library named after him here at Florida State University. Is this the same guy?
Basically blurriness.
The block artifacts in DCT/FFT based approaches such as MPEG-2 are due to the fact that video has local detail (well, duh!) but you're using a globally repeating waveform (FFT = sine, or DCT = cosine) to encode it. In order to represent local detail with a DCT-based tranforrm you have to divide the image into blocks to localize the transform, and when you throw away the lower order transform coefficients (which is basically what transform-based encoding is all about) those block boundaries become apparent - block artifacts.
In contract, wavelets are spatially localized / non-repeating, so you can represent local detail without needing to introduce blocks. But, when you throw away your lower order coefficients you will see bits of the image represented by only the higher order wavelets, which (wavelets being smooth) means that there'll be blurriness.
The BBC codec might still choose to use blocks for motion compression (I don't know), but the above basically explains the difference between the two, and definitely applies to the difference between image compression using DCT (JPEG) vs wavelet (JPEG2000) compression.
Your post sums things up quite well. Because we all pay for it, they have a duty to make sure it's available to all.
And that duty's not just 'something they should do to be nice', it's the law -- the Royal Charter and Agreement which the BBC operates under makes this clear.
Incidentally, the BBC are pretty big Linux/F/OSS proponents. Their entire BBC Interactive digital service is run from Linux systems. There are some very clever folk at the Beeb, used to 'rolling their own' technologies. I'd imagine something like Linux is the perfect tool to do this kinda stuff with. They've got vast amounts of in-house software and hardware which they've developed over the best part of a century.
Anyone else remember the BBC Micro? They, and the Open University have to take quite a significant amount of credit for kick-starting interest in computing in the UK during the late 70's and early 80's.
Incidentally, the Open University, whose course materials BBC 2 broadcast nationally and for free, is a fantastic organisation. Like the BBC, it was founded by Royal Charter, and is another example of how something spawned by government need not be tethered to it. It's been a highly respected institution from which to graduate for decades. Here's some info
What's the frequency, Kenneth?
Don't forget that "Friends" US --> UK "Coupling".
Not really. Friends is about... well, friends,and Coupleing is about coupling. Yes, the format has obvious similarities, but the the characters are different, the type of humour is different, the relationships are all different.
There was a made-in-the-US version of "Red Dwarf"? Did not know that.
They tried twice. Two pilots. Actually, according to one of the writers the second pilot was great until the studios got their hands on it.
Here are two extremely successful UK to US sitcom adaptations:
I was not aware of those. I stand corrected. Perhaps it's just a recent thing that they've been oversanitising them, or something.
Include the memory access operations and the wavelet transform looses horribly for most reasonable architectures.
Water looked alot better, still had some problems with key frames ghosting arround sharp edges the picture improved after a few deltas. It was pretty neat however sound is still a problem ogg is not high fi enough so they are going to license something.
James
Guys, as you may know we are busy building the world best 100% open source media player, called the Helix Player (https://player.helixcommunity.org). We welcome all open source codecs and formats, including Dirac.
Secondly, this summer we will be releasing the RealPlayer 10 for Linux, which is built on top the Helix Player and includes the non-open source components of MP3, MPEG4, Flash, and RealAudio and RealVideo.
Both the Helix Player and RealPlayer 10 have a Mozilla plug-in and are going to be a major no cost update for your current RealPlayer 8.
Kevin Foreman