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ffmpeg: Free Software's WMA decoder

Posted by CmdrTaco on from the way-to-go-guys dept.

mmu_man writes "This morning, after the usual spams, I got this from the ffmpeg-devel mailing list: Here it is, something we waited for long. Now we have a FreeSoftware (LGPL) WMA (Windows Media Audio) decoder. WMA is the highly proprietary audio codec M$ is pushing along with its user-locking tools like DRM. this will free us from the ugly DLL hacks required to play DivX until now. Note there isn't any encoder yet, but who would like to encode into WMA while we have better and more open solutions? With this new codec, ffmpeg really proves itself as the most complete audio/video grabbing, convertion and streaming solution, for Linux, but also FreeBSD, Windows and even BeOS. Note ffmpeg codecs are used in a lot of other FreeSoftware projects, like mplayer."

24 of 245 comments (clear)

  1. How long before... by meringuoid · · Score: 4, Interesting

    ...MS decide this is illegal and start suing? I mean, clearly there's the whole DMCA thing. Does this decoder ignore MS's DRM system? I would have read the article, but I don't speak C...

    --
    Real Daleks don't climb stairs - they level the building.
    1. Re:How long before... by Anonymous Coward · · Score: 4, Interesting

      It's been previously established that ignoring is not the same as circumventing.

    2. Re:How long before... by NanoGator · · Score: 5, Interesting

      "MS decide this is illegal and start suing? I mean, clearly there's the whole DMCA thing. Does this decoder ignore MS's DRM system? I would have read the article, but I don't speak C...
      "

      Anybody remember when VirtualDub could work on .ASF files...?

      Here is a short blurb talking about it.

      --
      "Derp de derp."
    3. Re:How long before... by FreeUser · · Score: 5, Interesting

      How long before... ...MS decide this is illegal and start suing?

      How about sometime after Microsoft actually uses a lawsuit as a weapon? Microsoft has zero history of suing people who write lookalikes of their software (Samba, WINE, That NT-workalike project, etc).

      Well, that is true only to a point. In fairness to Microsoft, they haven't filed any such lawsuits, but they have used the threat of lawsuits on more than one occasion, and while they haven't dealt with look-and-feel per se, they have dealt with other equally inane things, like file format compatability. Certainly Microsoft has reserved the option to (mis)use lawsuits strategicly against Free Software in the internal Halloween documents leaked a few years ago.

      Apparently, you're thinking of Apple who really is truly evil when it comes to suing people.

      Both are evil, in different ways. However, I believe you are correct in pointing out that Apple is the one which went beyond mere intimidation, to actually filing (and losing) lawsuits based upon mimicknig look-and-feel.

      Which is why, much as I like some of Apple's products (and will almost certainly make Apple my next laptop), I am also at pains to point out that anyone switching from Windows to Apple is simply trading one Master for another, and who is to say that the kinder Master today will be the kinder Master next year?

      Of course, with Palladium on the horizon, we may well find ourselves in the extraordinarilly ironic situation where we need to buy a non-Intel, non-AMD (e.g. Apple PowerPC) system just to be able to dual-boot into Linux. I suspect instead most of the Asian hardware companies will ship with two BIOSes, so that a simple jumper or firmware setting can completely eliminate Palladium, but who can ever be certain in these unusual times?

      --
      The Future of Human Evolution: Autonomy
    4. Re:How long before... by Anonymous Coward · · Score: 3, Interesting

      I'm responding to your .sig, which is actually still on topic for this discussion.

      (The .sig I'm responding to currently reads: "Paranoids: explain how Palladium will prevent all unsigned code/mp3s, yet maintain backward compatibility.")

      The answer is: it won't prevent unsigned code/mp3s[/wma]. You can run all the unsigned code you want (if you have an app that supports it). You can run an unsigned OS if you want. However, what the underlying TCPA hardware will allow that unsigned code to do is very limited.

      Under TCPA/Palladium, you WILL be able to:
      - load and run an unsigned kernel
      - play unsigned content
      - etc.

      You will NOT be able to:
      - access certain parts of the system from that unsigned kernel
      - access signed content from that unsigned kernel/code in a way that lets you get around the DRM
      - write unsigned code that has any ability to view signed/protected content that doesn't allow that

      This is all assuming, of course, that the code works just like it's supposed to and doesn't have any bugs that amount to back doors. Peter Biddle (group manager of the software techs writing Palladium at MS) has said publically (Usenix Security Conference '02) that he and his associates fully expect that -- even after Palladium is rolled out -- any content released in any protected digital format *will* be cracked open and re-released in an open format to the P2P services within hours. This was one of his answers to the "how do you write this code and still sleep at night" line of questioning. He knows their managers want this written to satisfy the (MP|RI)AA, but doesn't believe it'll work for that, so thinks his group is excused from the moral problem.

    5. Re:How long before... by Anonymous Coward · · Score: 2, Interesting

      It doesn't have a DRM implementation (either v1, v2 or v2.1), so it cannot read protected content.

      However, FreeMe can be used against v2 (and v2.1) in certain circumstances. The unfuck workaround for v1, which is more common (i.e., the version produced by XP's media player when ripping with default settings) transcodes the file to 64kbps, and is thus really icky and not recommended.

      The fact that a free decoder (although it'll likely be under imminent legal assault - get your mirrors ready, people!) now exists, however, has prompted me to restart work on my no-license-required v2/2.1 system break (you don't get something for nothing, MS) and v1 known plaintext attacks again, in an attempt to make them both practical and rapid, without using drmclien, indivbox, or drmstor (which would just be changed with countermeasures).

      Watch sci.crypt, cryptome and here for releases if I succeed.

  2. Is this REALLY a good thing? by GnomeKing · · Score: 5, Interesting

    Sure, I'm all in favour of being able to play more movies on my linux system - even though I'm unlikely to own (m)any wmv movies...

    But my question is how legal is this?

    What is to stop MS attacking open source in the same way as RIAA attacked - and closed - napster?

    yes, yes, one is a concept, the other is a program - but RIAA wants to make ANY file sharing program which is similar to napster illegal, and their certainly making progress toward that goal...

    If a percentage of open source developers ignore the law - such as a percentage of napster users did - whats going to happen in the future?

    1. Re:Is this REALLY a good thing? by Zathruss · · Score: 2, Interesting

      This is really off topic. But I was wondering; what happens if you are based in the USA, but write the software remotely; ie: the software source code is written, stored, compiled and run on a maching based in some little country no one has ever heard of. Lets assume that there is no cache of any sort on your local machine, like you're using it as a dumb terminal. What happens then?

  3. Quality "Enhancements" by __Maad__ · · Score: 5, Interesting

    I remember someone mentioning in an earier discussion that the WMA encoder fooled many people into thinking their encoded audio sounded "better" by applying a compressor/dynamics (6:1 ratio was it?), leaving the dynamic range 'squished' and making music sound louder (which isn't really "better"). Can anybody confirm this?

    If an open version of a WMA encoder is released, it would be interesting to see how it would perform versus the MS encoder in this respect.

    --
    Maciek

    --
    -- Maciek
    1. Re:Quality "Enhancements" by Anonymous Coward · · Score: 1, Interesting

      I've never understood what the != thing was all about. It obvisouly means the first part really isn't equal to the second part, but where did it originate?

  4. How does this relate to Divx? by magnum3065 · · Score: 2, Interesting

    Could someone explain what WMA has to do with Divx?

  5. Truly great! by mr_z_beeblebrox · · Score: 3, Interesting

    Unfortunately, how long will it be before MS "improves" WMA encoding now? I think it is an unsafe target decoding MS files as they can change everything and you are back to development.
    However, with MS new licensing and the fact that most tools are fairly robust. You might grab share if you can record and playback. Though with examples like Star Office I wonder how much grabbing you would do.

  6. Latest WMA? And will MS try to shut it down? by burgburgburg · · Score: 3, Interesting

    Does this decode the latest version of WMA files? What does it do about/with the DRM component of such files? And in consideration of this, will MS use the DCMA (or some "you must have agreed to the EULA not to reverse engineer if you've ever downloaded a WMA file in your life" argument) to shut this effort down?

  7. Liability? by m0i · · Score: 5, Interesting

    Can this source code be subjected to DMCA?
    Can its author be sued for reverse engineering?
    Is it planned that DRM features will be added at some point, or the above applies..

    --
    have you been defaced today?
  8. Isn't the WMA format patented? by Anonymous Coward · · Score: 5, Interesting

    I'm sure I remember a /. article from someone who was closed down by Microsoft (read: sent threatening letters) for attempting to produce a WMA decoder. The argument then was that the WMA format was covered by various patents.

    What's to stop the same thing happening to this one?

  9. Patent problems with this? by FattMattP · · Score: 5, Interesting

    Are they sure that this isn't covered by a patent? I remember almost two years ago that VirtualDub had to remove support for ASF files because Microsoft had a patent on some part of it. The VirtualDub guys just removed support rather than fight MS. I hope this doesn't turn out to be the same situation.

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    Prevent email address forgery. Publish SPF records for y
  10. EULA for WMAs by Spaceman40 · · Score: 2, Interesting

    A while ago I was going to switch all my WMAs over to MP3 format (Acid doesn't like WMAs as input), but when I went into Nero (which can decode/encode multiple files with one command) it said that it's not allowed to decode WMA files - something about Microsoft saying it's bad.

    Have any of you seen this?

    --
    I [may] disapprove of what you say, but I will defend to the death your right to say it.
  11. stable interfaces by den_erpel · · Score: 4, Interesting

    The only pitty is that there are no real stable interfaces to the library, which makes a lot of projects to statically link the libraries :(

    We changed the upstream sources a bit to provide libavcodec and libavformat as shlibs and started using dynamic linking.

    As long as ppl use the sources provided with the debs and compile, no problem, but it's hacking time again when someone gets a CVS release :X Oh well, that's what makes life (and coding) interesting of course ;) -and trying to capture possible problems with m4 macros >:)-

    --
    Genius doesn't work on an assembly line basis. You can't simply say, "Today I will be brilliant."
  12. A free WMA decoder promotes Microsoft standards by fluor2 · · Score: 2, Interesting

    I'm afraid that a free WMA decoder promotes Microsoft standards, instead of promoting the use of open standards.

    I think it would actually be better to never make anything else than OGG decoders to conquer the push from software giants.

    Also, would be nice if you linked up to www.xvid.org, that also is free.

  13. no petrol but many ideas by Anonymous Coward · · Score: 2, Interesting

    I don't want to start a flame war there but did you know that:

    * FFmpeg was started by a french group (maybe just a french guy)
    * DivX was invented by a french guy
    * another beautiful player, VideoLAN, is made by a French group

    As the french say, "we might not have petrol in France, but we have ideas".

    Artaxerxes

  14. How did they do it? by skeedlelee · · Score: 2, Interesting

    With all the discussion of is this or isn't this a patent/lawsuit problem, it seems an important question is being missed. How did they make the (co)dec? The article itself doesn't mention it and short of digging into their dev site, I don't know how to figure that out. Anyone involved with the project care to share?

    I can think of two very different ways to get at it. Try and dig the decoder out of MS code or give it a bunch of training files and tweak the decoder until it sounded right. (ouch that sounds like a painful project) If the latter, then I don't really see how there could be any sort of lawsuit issues, unless there's a EULA problem (can't use WMP in developing competing software or something). It's a bit reminiscent of the Samba approach. Also, without a encoder, (IANAL) you shouldn't run into problems even if the wma format itself is patented.

  15. Re:Why not MIT X license instead of GPL? by spitzak · · Score: 3, Interesting
    Maybe because the writer wants to sell the code to proprietary software developers?

    No, that would not fit into your "the GPL is a Communist conspiracy" theory. In fact the GPL is put on code for extremely selfish reasons that would make Ayn Rand proud.

  16. Two words: by Anonymous Coward · · Score: 1, Interesting

    Winamp Plugin.

    Using this library to build a standalone WMA decoder plugin that doesn't use the system libraries (and hence, isn't obnoxious about where it will output too) would be really really nice, especially after MS told Nullsoft to cripple their system library one.

  17. Re:Misleading writeup by megabeck42 · · Score: 2, Interesting

    Actually, an interesting thing I noticed the other day, is that a bunch of divx's are being released with downsampled or original AC3 tracks, so if you have alsa and a spdif capable soundcard (cmi, fm801), you can get dolby goodness. A websearch indicates they were probably encoded with a patched version of nandub. mplayer handles this great to: mplayer -ao alsa9 -ac hwac3 .avi

    Of course, if you don't have all that, mplayer will happily do the AC3 decoding and output regular audio.

    --
    fnord.