Dirac 1.0.0 Released

dylan_- writes "According to their website, 'Dirac is an advanced royalty-free video compression format designed for a wide range of uses, from delivering low-resolution web content to broadcasting HD and beyond, to near-lossless studio editing.' Now a stable version of the dirac-research codebase, Dirac 1.0.0, has been released. The BBC have already successfully used the new codec during the Beijing Olympics and are looking to push it to more general use throughout the organisation. The latest version of VLC (the recently released 0.9.2) has support for Dirac using the Schroedinger library."

Comments

really?

[Anonymous Coward]

Remember when we all used GIF until somebody came out of the closet with a patent claim. How can we be sure about this one?

Re:really?

[whathappenedtomonday]

Read their site. From the FAQ:

Do you infringe any patents?

The short answer is that we don't know for certain, but we're pretty sure we don't.
We haven't employed armies of lawyers to trawl through the tens of thousands of video compression techniques. That's not the way to invent a successful algorithm. Instead we've tried to use techniques of long standing in novel ways.

What will you do if you infringe patents?

Code round them, first and foremost. There are many alternative techniques to each of the technologies used within Dirac.
Dirac is relatively modular (which is one reason why it's a conventional hybrid codec rather than, say, 3D wavelets) so removing or adding tools was relatively easy, even though this may mean issuing a new version of the specification.

Re:really?

[Anonymous Coward]

The real question is, how does it fare against good H.264 encoders e.g. x264? And how are the encoding speeds?

The few comparisons I've seen put H.264 as having the edge when it comes to both, but not by a lot.

Re:really?

[David Gerard]

Encoding and decoding is presently fat and slow. It's very much in development.

Re:really?

[whathappenedtomonday]

Since you claim this I assume that you tried the 1.0.0 already - I watched the promo vid, and it says the BBC is using the codec to handle HD content over their standard def infrastructure at very low latency (a few ms, if I remember correctly).

Nonetheless, this seems to be an interesting thing to keep an eye on, because the codec specs address good compression especially for very high bandwidths, which is going to be an important issue for movie post production/processing, HD content and the likes. The promo vid is well worth watching.

Great, but...

[Anonymous Coward]

I tried using the Schrodinger library but I'm uncertain it works. Plus, I can't find my cat.

Re:Great, but...

[Anonymous Coward]

Plus, I can't find my cat.

Be glad for that, as long as you dont you might still have one.

Re:Great, but...

[Hangeron]

I had success integrating Dirac, and got a result of 1.

Re:Great, but...

[tobiasly]

I tried using the Schrodinger library but I'm uncertain it works. Plus, I can't find my cat.

I hate to tell you, but your cat is dead. And/or not.

Re:Great, but...

[John Hasler]

You may have loaded libheisenberg instead. They sometimes become entangled.

0xBBCD

[hey]

I see the first 4 bytes are 0xBBCD.
British Broadcasting Corporation Dirac.

Re:0xBBCD

[Anonymous Coward]

Did you mean to say the FOURCC (which is usually not the first four bytes) is 'BBCD'? 0xBBCD is usually two bytes...

Re:0xBBCD

[Anonymous Coward]

Isn't that just 2 bytes? :)

*nibbles on parent's geek card*

Re:0xBBCD

[Bloater]

the fourcc is 'drac'

Re:0xBBCD

[dougisfunny]

The size of a byte doesn't have to be 8 bits, though it usually is.

Re:0xBBCD

[Yetihehe]

It doesn't? It's Blasphemy! In the beginning, there was word. And in word there was two bytes. In two bytes there was 16 bits. And the root saw it was good.

Open source overkill

[mdmkolbe]

From the FAQ:

What are the license conditions?

The Schrodinger software is available under any of the GPLv2, MIT or MPL licences. Libraries may also be used under LGPL.

Sounds like someone wanted there to be no question about whether it was open source.

Re:Open source overkill

[damn_registrars]

The Schrodinger software is available under any of the GPLv2, MIT or MPL licences. Libraries may also be used under LGPL.

Sounds like someone wanted there to be no question about whether it was open source.

Sounds to me like the license exists in multiple states at once, which may be exactly the way Schrodinger would have liked it.

Re:Open source overkill

[Anonymous Coward]

I am not sure, but isn't MIT one good enough to relicense it to (L)GPL or MPL?

Re:Open source overkill

[MrWim]

The GPL makes assurances regarding patents that the MIT license doesn't:

"Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version."

So if you use it as a GPL licensed library you can't get sued by the BBC or other contributors to the code.

Re:Open source overkill

[dapyx]

No, the GPLv3 has clauses about using the code in a DRM system, the anti-patents clause has been for a long time.

Performance? Benefits?

[Enderandrew]

How does it stack up to other codecs?

Do we need another codec?

Content

[whathappenedtomonday]

I was wondering where I could find some vids to check out quality vs. file sizes and found this index of demo files. Looks great in VLC, quite impressive even at lower bitrates.

Re:Performance? Benefits?

[fuzzyfuzzyfungus]

We don't need another codec, per se, we need a royalty free codec, that can be legally implemented in FOSS situations, and others without a lot of legal overhead. Assuming it isn't markedly worse than others in performance terms, Dirac qualifies. If by some miracle(class II or greater) mpeg4 were available under such terms, there wouldn't be any point to Dirac; but that isn't exactly likely.

News from OGG Theora, too!

[c0l0]

Dirac isn't the only royality-free, patent-unencumbered video codec there is - Xiph's OGG Theora has been around a while already, yet failed to impress quality-wise up until recently. There's some really cool development going on however, and you may see some of the results achieved over there: http://xiphmont.livejournal.com/35363.html

It's noteworthy that the changes made only affect the ENCODER, thus no changes to the DECODER (the part of a codec all applications used to play back files have included) are necessary. This bodes very well for HTML5, which will include some support for Theora on at least Mozilla (and iirc Opera) browsers.

Re:News from OGG Theora, too!

[Tab is on Slashdot]

Theora gets a bad rap for being outdated technology, but it does have a few advantages over MPEG-4 ASP: the loop filter, adaptive block sizes, and multiple reference frames, putting it closer to H.264 than MPEG-4 ASP. With these features, it's really a pretty strong showing from Xiph, and things can only get better as the encoder nears 1.0.

Re:News from OGG Theora, too!

[delt0r]

This is a big point. The Encoder is far more important that the rest of the codec. Folks talk about xvid and divx as if they are codecs when really they are different encoders for mpeg4.

Both Theora and Dirac have plenty of space to move with regard to encoders.

However there is no easy way to measure "distortion" of the encoded image that matches the human visual system all that well. (unlike audio). But I expect most codecs to get better in the next few years because of encoders. (including h264).

Ironically h264 does so well because of the availability of a free, fast and good quality encoder done my the community. Not the license owners.

Re:News from OGG Theora, too!

[mdmkolbe]

However there is no easy way to measure "distortion" of the encoded image that matches the human visual system all that well. (unlike audio).

How do you objectively measure psychoacoustic distortion? Do the same techniques not apply to vision simply due to unknown constants or is there some more fundamental reason?

Re:News from OGG Theora, too!

[delt0r]

In sound the idea of masking works really well. That is if there is a loud sound at a particular frequency we tend to not be able to hear sounds that are a low in pitch and a bit quieter (IIRC). Its effectively masked. The other big advantage is also the linear nature of sound.

But the human visual system is a *lot* more complicated. IIRC about 1/3 or our brains are used for visual perception. Currently we use PSNR (Peek signal to noise ratio) as a measure. But this has been shown many times to be a very poor indication of what we perceive. One example is blocking. Blocking cause straight lines to form in the image and our brains lock on to them far more quickly that other artifacts.

Next is the colour and the 2d nature of a image. Then add that the eyes do a bunch of preprocessing on motion perception and its getting quite difficult. Finally we have the method of comparison. Which often involves comparing still images from the video stream. Yet if thats a high motion scene the codec might be better off encoding these frames with low quality because we can't perceive the quality loss combined with fast motion.

Lets also not forget how many people think youtube is good quality or at worse, good enough!

Re:News from OGG Theora, too!

[delt0r]

All the R&D papers I have read and from folk in the field working on this. Its well recognized that psychoacoustic models are far more developed than psycho visual models.

I don't doubt that some people can tell the difference between flac and mp3/ogg/aac. But the true number is far less than the claimed number (do a proper blind test to really find out). Also you don't design codecs for 0.5% of the population that can hear the difference, but for the 90% that can't and the other 9.5% that don't care.

Now its a fact that PSNR is used in most encoders. Its also widely recognized that it is not a good measure. I have done my own image compression and got better PSNR than jpeg per bit, and yet it looked far worse.

So I'm not really sure where you getting the idea that is even in the same category as audio.

Re:Performance? Benefits?

[Tab is on Slashdot]

How does it stack up to other codecs?

As I say below, unfortunately the quality is lacking compared to modern codecs like H.264 and even (dare I say) VC-1. Apparently that's just the nature of using wavelets. While they give a very natural style of compression on still images (JPEG-2000, etc), they do not translate well to moving sequences because, unlike all other current codecs, the image is not broken up into blocks that can then be tracked and diff'd in time. Still, it'll be interesting to follow Dirac, if only because they're taking a radical new approach with only Michael Niedermayer's Snow as a peer.

Re:For low values of success

[ATMD]

Could it be that the BBC's slowness to offer HD is related to the fact that most license payers receive their broadcasts via analogue or "Freeview" digital, neither of which currently support it? I guess they have better things to spend their limited budget on.

Re:Performance? Benefits?

[delt0r]

As I state below. Most of codecs performance has to do with the encoder. At 1.0.0 its too early to tell if the format/codec design is limited.

However a great codec without a good encoder is no good at all. But its early days yet considering h.264 has been around for 5+ years.

Re:Performance? Benefits?

[Tab is on Slashdot]

Dirac employs wavelet compression, instead of the discrete cosine transforms used in most older codecs (such as H.264/MPEG-4 AVC or SMPTE's VC-1). Dirac is one of several projects attempting to apply wavelets to video compression. Others include Rududu [2], Snow and Tarkin. Wavelet compression has already proven its viability in the JPEG 2000 compression standard for photographic images.

Yes it does :|

Re:For low values of success

[lxt]

16mm is a perfectly viable format for 24p HD, so your question is something of a contradiction. Sure, the quality might not be as good as it could be, but it serves a niche market for low budget HD output on 'quality' drama. Comparing the BBC's HD drama output to the stuff in the States is disingenuous, not least because HD penetration in the UK is extremely low but also because shows in the UK tend to run on lower budgets anyway than prime-time US serials.

Re:For low values of success

[Anonymous Coward]

In a nutshell, yes. HD is also not much of a big deal to the vast majority of television viewers either. The only reason there is such a fuss over it in the United States is mostly because they are rolling out HD and digital at the same time: most of the improvement has come from the change to digital, not HD. In Europe it's not such a big deal because we've already switched to digital. HD is "nice" but it's not the huge leap in visual quality some people would like you to believe.

Re:For low values of success

[PopeRatzo]

Id guess that at least about 40% of all shots from news or sports footage is overexposed by at least 2 stops.

And I thought that was some kind of UK New Wave artsy Duane Hopkins/dogma thing they were going for.

Once again, I mistake incompetence for artistic innovation.

Re:For low values of success

[ttlgDaveh]

Someone's evidentially not been watching Top Gear, which features some of the best camera work on TV and film.

Re:Performance? Benefits?

[Ant P.]

The codec is new, give it a few months.

Early DVDs looked like shitty 90% compressed jpegs too, you know.

Re:Where is the windows codec.

[figleaf]

I downloaded the code from sourceforge and compiled the code using Visual Studio 2008.
Looks like the encoder is distributed in source format only. I could not locate any pre-built binaries.

I am having trouble figuring out what the command-line parameters mean from the README supplied in the source tarball.
This certainly needs better documentation for non technical users.

The samples certainly look impressive. I will try to compare it against my current favorite encoder -- x264 -- over the weekend.

Re:Performance? Benefits?

[Tab is on Slashdot]

Update: I've been told by the devs that Dirac is optimized for HD live action, wheres my tests have thus far involved SD animated content, so, YMMV. I'll have to try some live action sources next.

Re:For low values of success

[RonnyJ]

I strongly disagree that "most of the improvement has come from the change to digital, not HD". TVs don't magically become a higher resolution when you add a digital decoder! The main benefit(?) of digital has been more channels.

I see a huge difference in quality between SD and HD. The most damaging thing for HD that I've seen is that many retailers used to play SD content on HDTVs, which isn't particularly suited for a TFT/LCD screen and can look terrible.

Re:Performance? Benefits?

[Tweenk]

Matroska is not a codec. It is a container format, and it beats any closed-source competitions hands own on features (e.g. as far as I know it is the only format that supports embedding custom TrueType fonts for subtitles).

The best video encoding combo right now is:
- Matroska as the container
- H.264 for video
- Ogg Vorbis for audio
- ASS for subtitles

Re:For low values of success

[hairyfeet]

Yes,it is nice to have HD,the problem is that the big companies will ruin it by compressing the hell out of it to squeeze in more channels. personally,seeing as how many artifacts end up in the overly compressed HD,I'd personally rather have uncompressed SD than HD,thank you very much. I'm just lucky I'm on a small cableco that is going to stick with SD until they are finished upgrading their network,which they figure will take around 2 years. New servers,lots of fiber being laid,and with each new piece my Internet connection gets a little faster and snappier. But if all the providers start compressing the hell out of the HD signals I don't see HD adoption taking off. Who in the hell would want HD if they compress it so bad it looks like a low bitrate .wmv? But as always this is my 02c,YMMV

Re:Performance? Benefits?

[Dwedit]

How does Vorbis really compare against AAC? Besides the whole royalty/patent free issue, does Vorbis really beat out AAC? (Ignoring royalty/patent issues here because you also mentioned H264)

Re:Where is the windows codec.

[figleaf]

Took me a while to figure I needed to use YUV input.
Unfortunately, it looks like Dirac is no match for x264. :(
Even VC-1 beats Dirac.

Re:top gear = rockin' :)

[caluml]

Thanks for your support, TV licensees of Britain!

Uh, that's OK. Just send me some money, and I'll make sure it gets passed on to the right pub... I mean people.

Dirac? Schrodinger? wha...?

[aqk]

Hey, I KNEW those Atomic Physics courses I took way back in University would come in handy!

Who needs to compress time, when all you hafta do is compress the video.
If I took a video of my cat, and then compressed it with this new codec, would the cat be...
Umm.. never mind...!
.
.

Re:Free as in beer or speech?

[delt0r]

But if you're just distributing the source..

So now I can't also distribute binary but my freedom is not affected? I don't think I would want to test source=ok, binarys=!ok as far as patent law is concerned with my wallet. Economic harm is all thats needed if software patents are valid.

Theoretically true, although that hasn't happened much in practice, at least in this space.

So you pay a crap load of money and only don't get sued much? Thats a raw deal. There has been at least one case I know of with mpeg4 | h.264, and thats a lot more than what both theora and dirac have had to deal with. Add the fact that theora is based on VP3 with a active company now with VP7. That they are active with this "IP".

and don't have the market effect of lots of companies looking for patents to assert to get a share of the MPEG-LA revenue.

And yet these codecs are the only ones that have any history of problems.

Have you actually all of the H.264 or VC-1 patents?

Not all, but most of them. I even got "advice" and we did decide that most could be overturned with prior art, patenting math, and obviousness. But the cost and most importantly *time* that this would take... Its not that there is one, its that there 10+ or more for each company in the pool.

If anything H.264 and VC-1 are much more reasonable than MPEG-2...

This is true. Its a lot better. And yet still discriminates against OS ideals of freedom and free. Yes you lose freedom, no matter how slice it.

There are patents that are free to license for free GPL type products. These do not reduce freedom. The patents we are talking about do. Software patents in general do. Our freedom is reduced if they apply to code we write.

Another problem is what you are expected to sign up to when you get a license. This license itself is also restrictive. So if you donate that +3 million per annum cap to the mplayer/ffmpeg whatever group so they can release legal worldwide free codecs, I think you will find that the license will prevent this. After all what would all the other licensees think.... If the license dose not prevent this it would not take long to do so, as mpeg-la reduce themselfs to a single licensee (everyone else can just use mplayer/ffmpeg code even in hardware players).

Re:For low values of success

[funkatron]

Top Gear isn't about cars, they're just used to give the presenters something to argue about.