More On The BBC's Codec 'Dirac' 278
TioHoltzman writes "El Reg is reporting about a new codec that is built on top of wavelet technology and seems to offer performance that is "roughly in line with the Video Codec 9" from Microsoft. The project has been released as open source on SourceForge. This looks like it might be really interesting." (Previously mentioned a few weeks back.)
patents on arithmetic coding? (Score:5, Interesting)
Re:patents on arithmetic coding? (Score:5, Insightful)
patents, pixlet and jpeg (Score:5, Informative)
as for wavelet compression being a novel codec, what about apple's pixlet technology?
Re:patents, pixlet and jpeg (Score:3, Interesting)
Pixlet (Score:5, Informative)
Pixlet is designed for real-time editing, so it has minimal artifacts and no interframe compression. Dirac is for broadcast, so it is much more agressive about compression and can take advantage of motion compensation and other computationally expensive compression techniques.
You are right, however, that wavelets are not at all a new compression technology. People started playing with it at least 10 years ago and JPEG-2000 uses wavelets for still photo compression. I think that the computational load has prevented their use in video until recently.
patents? (Score:5, Informative)
Re:patents? (Score:2, Informative)
Re:patents? (Score:5, Insightful)
Looks interesting though. I think a lot of people ignore or marginalise the beed, when they've come out with a hell of a lot of innovation in their time. Let's hope this is one of the 'biggies' that they're responsible for.
Re:patents? (Score:2, Flamebait)
Re:patents? (Score:2)
Re:patents? (Score:2, Interesting)
Re:patents? (Score:5, Informative)
Unisys never had a problem with any of the LZW implementation in source form. They never asked for them to be pulled out of any site, and neither could they legally. What they asked is if you were using this technology for anything other than research and study (i.e. if you really wanted to compress some file with it for redistribution) *then* you needed a license from them.
The use of patented methods for research and study is legal, this is the whole point of patenting technology. Patenting is a publication process, in exchange for exclusive control of the technology *in applications*. The idea is that other people can study this technology and improve on it.
If you as a user take some source code floating on the net implementing some patented technology, and add it to some application, be the application free or not, you are responsible for obtaining a license from the holder of the patent, but AFAIK the author of the code is in the clear, and so are the distributors.
Re:patents? (Score:3, Insightful)
Well, we should put this in context though. Sure, the US only makes up 4-5% of the world, but the largest portion of the people in the world are thinking about how they are going to get their next meal, and don't even have any devices with any form of video playback, so they could care less about codecs.
In addition, and most importantly, the USA's 5% makes
Re:patents? (Score:5, Insightful)
I have a reply. GSM, DVB, DAB. All of these technologies are doing well despite the US not being a market. Two of them are the defacto standard outside of the US with some small exceptions. The other is becoming a standard.
You've got China and India and they are not as backward as you thing. The US is less than half the size of Europe, numbers wise. Add South America, Australisia, the Middle East, Asia etc and I'm afraid the US is rather out numbered by thriving markets who can afford the technology.
the USA's 5% makes up most of the scientific research in the world
Quote your source. This is complete bullshit. They do make up a large amount of the research but definitely not the majority.
Stop believing all that propaganda you keep hearing.
Re:patents? (Score:2)
Oh come now, it's not that undemocratic. If it was we wouldn't have been able to lobby against the corporations and win [newsforge.com]. Compare this with what happened in the US, where the govt bended over backwards to help the corporations.
New codec? (Score:5, Insightful)
Re:New codec? (Score:5, Interesting)
Everyone should read Stallman's essay The Right to Read [gnu.org]. When I first saw it, I thought it was so implausible that there was no need to worry about it. But since then I've observed much of the groundwork for this dystopia being laid. It is absolutely vital that consumers be educated to reject commercial technologies that take away their rights (including fair use), and instead prefer free and open technologies such as Dirac (assuming that it doesn't run into patent problems).
Re:New codec? (Score:3, Flamebait)
You forgot to mention Adobe - the one company who actually imprisoned someone [ebookweb.org] by doing exactly what you described.
Re:New codec? (Score:2)
Re:you can't make your own? (Score:2)
Re:New codec? (Score:4, Interesting)
Apparently the BBC is planning on allowing people to watch TV shows after thay are broadcast form the website. This codec development could be related to this.
Re:New codec? (Score:2, Informative)
In theory, the BBC hasn't been all that interested in profits, being a non-profit taxpayer funded organisation. I was starting to wonder what I payed a license fee for, but if they carry on like this I'll be quite happy to keep paying it.
I welcome the BBC's foray into OSS, and I hope it'll be the first of many OSS sucesses for them.
Re:New codec? (Score:5, Informative)
Many of us English folks grew up with the BBC Micro [mcmordie.co.uk] computer in schools.
Re:New codec? (Score:2)
Aah, I remember those. We had them in India too. Lovely machines. The other machines at school were the Tandy TRS-80, which nobody wanted to use. The IBM PC-AT already existed but was too expensive at the time.
Re:New codec? (Score:3, Insightful)
Only if there's a driving force to adopt the new standard. (Witness ogg/vorbis.)
The BBC do a lot to drive new technology - they've done computer and web education drives in the past, they're spending a huge amount of money on digital terrestrial channels that don't get audiences to drive adoption of that, they force-fed new technologoy to the kids on Radio 1 with webcams, SMS votes, etc., before everyone else caught on.
You
NOT a dupe ;) (Score:5, Funny)
Re:NOT a dupe ;) (Score:3, Funny)
$story_txt
&post( $story );
Re:NOT a dupe ;) (Score:2, Funny)
could be hopeful (Score:3, Insightful)
Re:could be hopeful (Score:2)
Maybe so... but the BBC's reputation seems to be sliding down a slippery slope when it comes to being a reputable, reliable publisher/broadcaster. A telling off for the BBC [aardvark.co.nz].
Re:could be hopeful (Score:2)
Re:could be hopeful (Score:2)
Are you sure that was really the reason he was bankrupted? It would appear, at least from the comments of one former US Defense Department official (as made on this TV documentary [interestingprojects.com]), there may have been a *lot* more to it than that.
Re:could be hopeful (Score:3, Insightful)
The reason for this greatness is that these mandates mean that there is the potential to use its clout to formulate these kind of public standards, codecs, browser standards, docu
What other methods? (Score:4, Interesting)
So what methods do these other compressions algorithms employ? I couldn't figure it out from google. It seemed as though H.264 was related to mpeg4? Also, is there a rough guess as to how effective wavelets will be when they're better developed?
Re:What other methods? (Score:5, Informative)
The basic idea of DCT is to transform the data into a series of waves, which tends to concentrate the data. Then you throw away part of the data, and then use lossless encoding on what is left. If you just threw away pixels, the result would be obvious in an image; but if you throw away part of the wave specification data, the results are not as obvious.
With DCT, consistent data sets compress very well (e.g., a blue sky or a white wall). Pictures with lots of sharp little edges (e.g., a field of blades of grass) compress much less well.
My understanding is that potentially wavelets will compress even better than the DCT. However, they are not enough better to be a huge win at the moment.
steveha
Re: What other methods? (Score:5, Informative)
This means that when information is dropped in each block (according to the compression required), the edges of blocks suffer in a way unrelated to the edge of adjacent blocks. The result -- as the quality decreases, the edges between blocks become more and more obvious, and the whole image becomes 'blocky'.
I believe this is one way that wavelet technology improves -- the individual wavelets are spread over the whole image, without regard for any blocks, and so the compression degrades much more gracefully.
As you say, the DCT converts each 8x8 block into a series of cosine waves, both horizontally and vertically in the block. Then, when it needs to reduce the space, it drops the higher-frequency coefficients first -- this is why sharp edges, with lots of high frequency information, suffer most. (You tend to find that lower-frequency coefficients try to compensate, giving the characteristic ripples near sharp edges.) Areas that are relatively smooth, with only low-frequency information to start with, suffer much less.
Another way JPEG loses information is by colour. The human eye is much more sensitive to fine changes in brightness than it is to fine changes in colour; so the picture is transformed from RGB into a brightness channel and two colour channels, and the brightness channel gets a greater share of the limited space. It's quite interesting, if you're, er, interested in that sort of thing...
Re: What other methods? (Score:2)
This may be a silly question (I've not really got much knowledge of video encoding), but can't the algorithm work out if most of the information in the block is high frequency and in that case start dropping the _low_ frequency components instead?
Re:What other methods? (Score:5, Interesting)
It needed some improvements (more searching), and had some faults: around when it came out, it took a 600MHz Alpha (The fastest processor at that time, or darn near it) 24hours for a 30-sec clip, because it used brute force, and the quality was good, and compared to other compression types they all were much larger, and some looked worse. The problem is the difficulty in finding the fractals that will work. Recreating the image is relatively easy.
Re:What other methods? (Score:3, Interesting)
Although I didn't see it, the lecturer talking about this at the time (he was researching in this area) said he'd seen fractal encodings of images which pull out more detail than was actually in the image that was encoded. Sounds like crazy talk to me though
Re:What other methods? (Score:3, Informative)
Unlike an 8x8 DCT (for example), fractal compression is generally scale independent. A block of pixels is represented by a contractive mapping that can be applied to ANY size block. The mapping is applied iteratively and can be proved to conver
Re:What other methods? (Score:2)
Sure. The fractal encoding is basically specifying the shapes of the various elements of the image, and then when you ask for more detail, it creates some. It's kind of like taking a scanned image, then converting it to a vector image (say, for Adobe Illustrator), then printing it at a large size.
You can buy fractal filters for Photoshop, that allow you to upsample your images to a larger si
Was it a hex-cell fractal image? (Score:2)
This system had the advantages t
Re:What other methods? (Score:4, Interesting)
Indeed. The problem with the effective fractal compression algorithms is basically that, while there is a fast inverse transform to go from compressed to raw form, there is no efficient forward transform to go from a raw frame to the compressed form. There have been some exceptions -- the University of Bath once did a simple fractal compression scheme that went fast in the forward direction, but the compression rates were not very good. TTBOMK, all of the fractal compression schemes that achieve high compression rates require searches over VERY large spaces. If you can develop a fast forward transform, you may not get rich, but you'll be famous within a small circle of mathematicians.
Re:I'd love some details (Score:2)
Sure. This is called "temporal compression", when you take advantage of the fact that over time, large blocks of the image stay the same. Change blocks, that just represent the difference, are very small (at least if the original video source is clean). And MPEG has a way to specify that a part of the image moved, so you can say "first move this block over there, then apply a change block".
Does this codec co
Re:What other methods? (Score:5, Informative)
While wavelets doesn't offer a breathtaking advantage in data rate vs. quality factor, it does appear to lend itself to a simpler implementation than does DCT, and unlike MPEG, which is very intensive on the encoder, wavelets places symmetrical burdens on encoder and decoder.
It was a core assumption in the design of MPEG that the world market for encoders was quite small (where have we heard that theme before???) Clearly, the assumption was false, and one advantage of switching to a wavelets technology would be reduced cost per unit for encoders.
Re:What other methods? (Score:2, Informative)
Re:What other methods? (Score:3, Informative)
H.264 is going to become "MPEG4 AVC", Advanced Visual Codec. This is one of the 3 compression standards due to be approved (or maybe actually approved by now) for HD-DVD. The other 2 are WM9 (love it or hate it) and MPEG2 (for thos
Am I the only one... (Score:5, Funny)
Re:Am I the only one... (Score:2)
Re:Am I the only one... (Score:5, Informative)
Re:Am I the only one... (Score:4, Funny)
Well you can't be too careful when you're dealing with Slashdotters with UID > 700000...
Re:Am I the only one... (Score:2)
Re:I think this codec ... (Score:2)
Re:It's a reference to his book, (Score:2)
Any connection to their archival project? (Score:5, Interesting)
Spam Vikings await.
Interesting article on wavelets (Score:5, Informative)
http://www.seyboldreports.com/SRIP/wavelet/ [seyboldreports.com]
steveha
Re:Interesting article on wavelets (Score:2, Informative)
There's a well known intro paper on wavelets here: Building your own wavelets at home [bell-labs.com] (Wim Sweldens and Peter Schröder, ACM SIGGRAPH 1996)
More here [caltech.edu].
Unfortunately it doesn't matter (yet) (Score:4, Interesting)
You only have to look at Mozilla/Firebird which have finally matured into reasonably solid stable products. Netscape innovated, then lost market share and IE got a foothold. Now it doesn't matter to most companies that there is once again a good alternative in Mozilla because it only has a small marketshare. In the case of MP3, it took more of a foothold earlier on but we're already seeing movement towards proprietary formats.
The only way that the open source community is going to do well here is to provide a single coherent product without branches that is trivial to install and use for the average non-technical computer user. Unfortunately the very nature of open source and free software makes this difficult, because you have to reach a consensus amongst a diverse range of very intelligent people with very different politcal agendas. Choosing a single united front is a huge challenge.
Forget the codec for a moment. If I want to install the latest client operating system from Microsoft there is only 1. (This is the ideal - I know we've had Me/98/XP running concurrently but that's still only 3). How many Linux distributions exist - each version with its quirks and styles. It may be fantastic from the point of view of evolution of the software. Its not going to get users switching over.
Re:Unfortunately it doesn't matter (yet) (Score:3, Insightful)
First of all, this is stupid. Imagine if we did away with all that pointless branching into different c
Re:Unfortunately it doesn't matter (yet) (Score:2)
The automakers have distinct and instantly recognizable product lines for each segment of the market. None of the hundreds of Linux distributions have the visibility of Windows or the Mac or as clearly defined a target audience.
Re:Unfortunately it doesn't matter (yet) (Score:5, Insightful)
May be true for other things, but definitely not true for codecs, you can have multiple codecs loaded and not experience any problems/inconvenience (like if you were switching word processors back and forth) with switching between playing files using different ones. Think of how much trouble you have playing a VCD, DVD, DivX (MPEG-1,2, and several implementations of 4).
Keep in mind this will also likely be driven by a HUGE (and quite good quality - it's BBC) media library being available in this format.
Re:Unfortunately it doesn't matter (yet) (Score:5, Insightful)
Re:Unfortunately it doesn't matter (yet) (Score:2)
The fact is the majority of users don't watch DivX's. If you could click on a link and play one without installing additional software, and if they all had cheap bandwidth they might.
Re: Unfortunately it doesn't matter (yet) (Score:2)
Yes, this has always been true.
However, perhaps we're reaching a time when being unrestricted, open-sourced, and freely available is perceived as an advantage -- by enough people to tilt the balance?
Or at least, so we can hope... And maybe we can help to make it happen?
Re:Unfortunately it doesn't matter (yet) (Score:2)
Re:Unfortunately it doesn't matter (yet) (Score:5, Insightful)
Secondly, IE "won" the browser wars because it was the best browser. It still is. The reason? Developers still code to the IE "spec", not W3C. In addition it's page loading/rendering speed and start-up is much faster than Mozilla. Simple fact, live with it. Mozilla is exactly what OSS is not supposed to be, particularly on Unix - it's 100% bloatware. Even on my 'nix boxes I have IE running under WINE because it's better.
Your last two paragraphs completely miss the point of the codec. The BBC is not releasing this for Linux users. They're creating an open format that they still control. They want us to put the time and effort into making it perfect so that everybody can share it. This has always been the way the BBC has worked from technical innovation through to it's creative stance - it gets the people who pay for it, involved in it. They do not care if the implementation makes Linux more viable - they will take any codec work and deploy it for the UK masses on windows. If they decide to release that particular build of it to you for free, be grateful.
Mark my words, within five years DIRAC will be bigger than MP3 is now.
Re:Unfortunately it doesn't matter (yet) (Score:3, Informative)
Mark my words, within five years DIRAC will be bigger than MP3 is now.
You're all too willing to predict the future. I wish I had your prescience. You may be right but like Bill Gates and Larry Ellison have been to the tune of many millions and they're the successful ones.
Exploit happy, are you? (Score:2)
You are suicidal my friend. The first things I do with Windows boxes I have to use is to remove IE, OE and the pesky MS Messenger. They are security threats. Hell, I wouldn't even use Windows if I had the choice but they are paying me to. Best browser my arse, what do you with thousands of popups that accumulate after an hour of browsing?
Re:Unfortunately it doesn't matter (yet) (Score:2)
Agreed. Also, unless it is bundled with Quicktime, Real or Windows Media, then it will also be a hard sell. At the same time remember we are talking about a video codec here, so it still needs som
Re:Unfortunately it doesn't matter (yet) (Score:2)
Re:Unfortunately it doesn't matter (yet) (Score:2)
Oh? Then tell me why most everything is available in Divx, and not WM9+ASF?
We are? Could have fooled me. I don't remember seeing very many music files being encoded in WMA nor in RealAudio. Most of them are s
We may start using it in ogg vorbis encapsulation! (Score:2, Interesting)
Common availability (Score:4, Interesting)
Not that this type of research should be discontinued, of course, but from the numerous projects I've been involved in that used streaming media, common availability was the biggest problem... we often had to produce video for Windows, Quicktime and Real. There are some environments (technophobes, corporations, and government) where you can't install a new plugin.
In fact I think a Java based media streaming applet might be a great solution, since Java has pretty good saturation (although *sigh* there is no entirely free software or open source Java implementation at this moment).
Re:Common availability (Score:2, Interesting)
Anyway, do you actually want to watch TV programs on your computer? More likely you want something that has the storage and networking functions of your PC, but also makes full use of your plasma screen or projector. In which case, you're looking at a custom media-centre PC. In which case, you can use cust
Re:Common availability (Score:2)
This is, of course, pure bullshit. I've written
codecs in C and in Java, and the performance of
Java can often be faster than C for typical codec
tasks like block DCTs. Not typically as fast as
Fortran, mind you, but on par with optimized
Common LISP, which is also faster than GCC on
x86 and PPC.
I've never made a similar comparison for fixed-point
or SIMDized code, so I'm only making the claim
for floating-point.
Re:Common availability (Score:2)
What codecs do you know of that are written purely in C?
Most of them make extensive use of assembly to pick-up performance. Since you can't have a java applet integrated with assembly code, but you can have C intigrated with C code, the choice is clear.
Also, I am skeptical of your claim anyhow. I've seen lots of attempts to put codecs in
Re:plugin (Score:3, Informative)
Dirac can help with that (Score:5, Interesting)
Yes, and why are so few codecs available? Two reasons: (1) most codecs out there are a software engineering mess and hence hard to integrate into anything, and (2) most of them are heavily covered by patents and copyrights so people can't just write a plug-in and distribute it.
Something like Dirac holds the promise of letting people create simple, self-contained, freely distributable players that either play stand-alone or can be easily plugged into browsers. Furthermore, the same is true for encoders, allowing people to create content more easily.
And, unlike MPEG encoders, which have lots of weird parameters and flags, Dirac looks like it is simple enough that making high-quality encodings does not require a Ph.D.
In fact I think a Java based media streaming applet might be a great solution, since Java has pretty good saturation (although *sigh* there is no entirely free software or open source Java implementation at this moment).
Well, even there, a simpler format can help: something like Dirac is probably a whole lot easier to re-implement in Java than something like MPEG4.
Would YOU solve the Dirac equation? (Score:5, Interesting)
While in Kyoto I tried to learn Japanese with a vengeance. I worked much harder at it, and got to a point where I could go around in taxis and do things. I took lessons from a Japanese man every day for an hour.
One day he was teaching me the word for "see." "All right," he said. "You want to say, 'May I see your garden?' What do you say?"
I made up a sentence with the word that I had just learned.
"No, no!" he said. "When you say to someone, 'Would you like to see my garden?' you use the first 'see.' But when you want to see someone else's garden, you must use another 'see,' which is more polite."
"Would you like to glance at my lousy garden?" is essentially what you're saying in the first case, but when you want to look at the other fella's garden, you have to say something like "May I observe your gorgeous garden?" So there's two different words you have to use.
Then he gave me another one: "You go to a temple and you want to look at the gardens
I made up a sentence, this time with the polite "see."
"No, no!" he said. "In the temple, the gardens are much more elegant. So you have to say something that would be equivalent to 'May I hang my eyes on your most exquisite gardens?'"
Three or four different words for one idea, because when I'm doing it, it's miserable; when you're doing it, it's elegant.
I was learning Japanese mainly for technical things, so I decided to check if this same problem existed among the scientists.
At the institute the next day, I said to the guys in the office, "How would I say in Japanese, 'I solve the Dirac equation'?"
They said such-and-so.
"OK. Now I want to say, 'Would you solve the Dirac equation?' -- how do I say that?"
"Well, you have to use a different word for 'solve,'" they say.
"Why?" I protested. "When I solve it, I do the same damn thing as when you solve it!"
"Well, yes, but it's a different word -- it's more polite."
I gave up. I decided that wasn't the language for me, and stopped learning Japanese.
Re:Would YOU solve the Dirac equation? (Score:2)
Named after this dude, mayhaps? (Score:3, Interesting)
can anyone explain... (Score:3, Interesting)
Re:can anyone explain... (Score:3, Insightful)
At this point you're not really supposed to use it, you are supposed to develop it.
Its time will come, assuming enough people are interested and contribute. I don't know anything about audio or video compression so I already counted myself out!
The *really* nice thing about wavelets (Score:5, Insightful)
The above just takes advantage of spatial similarity (if a pixel is one color, it's neighbors are probably similar), but you can also take advantage of temporal similarity (if a pixel is one color in this frame, it's probably a similar color in the next one). You can also do motion compression, though when you get to that level of optimization you generally lose the symmetry between sender and receiver resource consumption. Of course, that might just be another CS dissertation away.
Grammar (Score:2, Funny)
What about other codecs? (Score:2)
The VP3 codec [wikipedia.org] has been BSD-licensed, and unencumbered by patents since Sept, 2001. And, every major Unix media player can playback VP3.
Despite what you may have heard from doom9, VP3 is also extremely competitive with MPEG-4 (slightly better IMHO) and I know that I can convert MPEG-2 video to MPEG-4 in nearly-perfect quality, at about
let me see (Score:3, Interesting)
carnivore...
open video codec...
carnivore...
I wonder which cost more
Re:let me see (Score:2)
That's my point (Score:2)
I know the US government does fund cool things too, and the british government funds shit too, but it was a lighthearted point.
Re:Government? (Score:4, Insightful)
Re:Government? (Score:2)
They probably can't detect the reciever, but I'm sure they can detect the CRT very easily... It's putting out such a ridiculously large ammount of energy that it can be detected from meters away, and the picture can even be reconstructed from the radiation (see "Tempest").
It would be possible to detect a TV recieving over-the-air signals, although not easy... When your turner picks-up a signal, it
Re:Government? (Score:3, Informative)
It's at that point where you buy a licence, or tell them you don't own a TV.
Obviously, I've never tried this personally, but scuttlebutt (and TV adverts) indicate they send someone out to your house to see if you really don't have a TV. If you're muppet enough to have your TV visible from the road when you're using it, th
Re:Government? (Score:5, Insightful)
But the BBC isn't the government - it's public service broadcasting at its best (though it's not as good as it might be, since it feels the need to justify the license fee by playing the ratings game and filling the schedule with mindless drivel). The BBC has been at the forefront of broadcast engineering development since the 1920s, and I'm happy to see them contributing to the world once more.
And the top rate of income tax over here isn't 50%, it's 40% - I wish it was 50% for high earners, then perhaps they'd have less disposable income to push house prices beyond the reach of the rest of us.
Re:Government? (Score:5, Informative)
Re:Government? (Score:2, Informative)
http://www.bbc.co.uk/info/policies/charte [bbc.co.uk]
Re:Yes, BBC is a govt agency (Score:2, Informative)
It's an independent public body incorporated via a Royal Charter. Just because it appears soft-left doesn't mean this is encouraged or engineered by Government, it's much to their annoyance in fact, take the Dr. Kelly affair or their war coverage
Re:Doctoral thesis (Score:2)
steveha
Re:WMV must Die (Score:3, Insightful)
Re:WMV must Die (Score:2)
Re:Embedded codecs? (Score:2)
Embedding executable in data file is BAD, especially if it needs to be native executable to get any acceptable performance.