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DivX Codec Port Contest
mr.e@home.com writes: "Flashingyellow.com has started up a contest to port the DivX MPEG-4 codec to the Macintosh platform. The goal is a completely open-sourced, cross-platform codec for use with Quicktime (hoping the Linux port of Quicktime ever gets completed). Prize is $5000 and an iMac DV Special Edition."
If DivX is a Microsoft extended version of MPEG-4, then isn't it likely to be protected by both Microsoft and other MPEG-4 patents?
Is MPEG-4 any less encumbered by patents than MPEG-2?
Note that some patents (such as H.263) are so broad as to apparently ensure that ANY implementation will infringe.
Before you start shouting bloody murder, read the FAQ on the page. DivX is Microsoft's implmention of the MPEG-4 video standard that has been embraced and extended. DIVX is that awful DVD scheme from Circut City. You have been warned.
From the divx.st site: "DVD-Quality". Let's get one thing straight: DivX does not give you DVD-quality, and IMHO it doesn't even come close to DVDs. If you're a movie enthusiast, you'll know what I'm talking about.
:)
And yes, MPEG4 is a standard. Microsoft has implemented that standard. Their implementation is not called DivX. DivX (which has nothing to do with Circuit City) is Microsoft's MPEG4 codec which has been modified to allow the use of MP3 and WMA audio. (No, it's not blessed by MS
As you probably understand, I don't like DivX that much. It gives you great quality at a small filesize, but it's nowhere near DVD-quality.
I don't understand why anyone would spend time working on that port anyway. Go contribute to something like OVD ("Open" counterpart to DVD) instead. Checkout linuxvideo.org for more info.
Okay, just in case anybody's still confused, here's what DiVX really is: Microsoft includes a codec for MPEG 4 video compression with recent releases of Windows Media Player. I don't know how standards compliant this codec is, nor if the standard is really finalized anyway.
The problem with this codec from the perspective of your average Windows user is that it's locked to prevent it being used with even vaguely open file formats such as avi. Like the Windows Media Audio codec, you're supposed to be able to use it only with one of Microsoft's new closed file formats -- asf? -- which enforce "rights management" -- which makes it difficult to use the codecs to recompress DVDs and distribute them all over the world on GNUTELLA, which is what everyone wants to do with them.
DiVX is just a patch to the binary DLLs that relaxes this restriction, so you can create and play back avis using MPEG 4 compression. It also comes packaged with a pirated version of the fraunhoffer mp3 codec for audio, and a similarly cracked WMA audio codec in recent versions as well.
Regarding porting, it would probably be semi-easy to "port" DiVX to i386 Linux using Wine to interface with the DLL. AFAIK, Microsoft has a fairly standardized API for pluggable video codecs, and DiVX complies to this. I think a very useful and realistic project would be writing the glue to call these codecs from a linux app (Winelib has the ability to link in DLLs I think). This would give anyone using i386 Linux easy access to playback/encoding of all of the video codecs that come with Windows now and in the future, within xanim or whatever. And since the best Windows video compression program for DVD piracy -- FlaskMPEG -- is already GPL'd except for the codecs it has to link in, it would be easy to port to Linux as well. Admittedly we'd be stuck with binary codec libraries, but as all these codecs are heavily proprietary and patent-encumbered it's probably the best we can do anyway. Obviously this binary-recycling approach won't work for the contest of porting to the Mac, but frankly I think that's pretty hopeless anyway.
The MPEG 4 divx standard is totally unrelated to the DIVX fiasco. The name sharing is confusing but since one of them no longer exists it doesn't really hurt to reuse the name, I gues.
Anyway mpeg4 divx is a compression standard which apparently delivers good compression rates at the price of performance. Both encoding and decoding is more expensive than mpeg2. The result however is not bad. Apparently it is possible to compress a dvd to fit on one cd. Also the quality is not bad apparently although I have heard various reports about that ranging from "nearly as good as DVD" to worse than VCD. I suppose it depends very much on the type of movie you encode.
Jilles
hoping the Linux port of Quicktime ever gets completed
What is wrong with xanim ?? It plays quicktime movies, and uses ALL available codecs. Apple is preventing usage of the most common Sorensen codec under linux, and also failing to port their player to linux. In short, they are trying to dominate online movies while ACTIVELY blocking any use of their movie format under linux. Several other codecs provide Mark Podlipec with NDAs, and he links their codecs in as binary libraries - thus not revealing their source.
From the xanim home page
I have contacted Sorenson about licensing their codec. They responded that Apple won't allow them to license it to others. You may want to nicely send a single email message to Sorenson and Apple asking about unix and/or xanim support for the Sorenson video codec.
Sorensen email: support@s-vision.com
Apple: wish@hype.quicktime.apple.com