ffmpeg: Free Software's WMA decoder

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."

Comments

Re:Is this REALLY a good thing?

[GauteL]

I'm sorry if this post comes out as a flame, but repeat after me:
"Creating a compatible interpreter is not the same as pirating software"

This means that creating WINE is not the same as trading mp3s, and it's not the same as creating a trading ground for mp3s. They are not even closely related.

I do not know how often people post things like this. RIAA attacked and closed Napster because they created a trading ground for mp3s. WINE and ffmpeg is creating an implementation of the Win32-api and WMA-decoder respectively.

There are however TWO ways that this WMA-decoder might be illegal:
1. It might be breaking the DMCA, by reverse-engineering or by circumventing DRM. I do not know if this might apply though.
2. It might be a breach of some software patent in WMA.

It has _nothing_ to do with the napster situation however.

Uggg...

[Junta]

I presume this is a sign that .avi files with wma or ABR mp3 tracks, or maybe ac3 tracks are pretty much entrenched now in terms of market? First mp3 becomes entrenched and now this? .avi is a poor container format (vbr prohibited, for example). DivX is decent, but not really a 'standard'. It may be MPEG-4 compatible/complete (I have no idea), but the FourCC code on those files is 'DIVX', and that represents a non-standard approach. Of course, the FourCC is only relevant in .avi and something easily faked in alternative encoders, but it just irks me...

And CBR mp3 audio... ick... maybe it replicates the bug and plays VBR mp3 audio, but still, doesn't mp3 only support two channels?

I would love to see the proliferation of something much more elegant. Say 'MPG4' FourCC (if you must). .Ogg container over .avi, or quicktime, or, best yet, the official standard container format of MPEG-4 (which, if not identical, is highly similar to quicktime 6 and/or the .divx format (does anyone use that at all?). Was there an audio MPEG-4 codec to go with the video and container, or would Vorbis audio be the best option?

Re:How long before...

[Reality Master 101]

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).

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

Re:Truly great!

[gowen]

For future stuff yes, but for stuff alreay encoded this is magic code

Plus, WMA has been pushed hard for embedded devices, and changing the codec to make old decoders non-operational -- especially not-easily-updatable firmware -- would make them extremely unpopular with music hardware vendors.

Re:Why not MIT X license instead of GPL?

[Eric Seppanen]

The key difference is that it would be a good thing for the Ogg Vorbis format to spread and become as widely used as possible. Nobody really wants to sees WMA become any more popular; it's best to just offer basic functionality for *nix systems that wouldn't otherwise have it. It's a tight balance: trying to make the free system better without giving any more power to the secret format gods.

Re:Is this REALLY a good thing?

[colinleroy]

IANAL, but there are laws in France (where ffmeg's main developer lives) that allow reverse-engineering programs to achieve interoperability, when no other ways (like documentation) can be used. RIAA and DMCA and such are non-valid in France, too. Given that and the fact that WMA is 100% undocumented, i guess Microsoft can't do much about this.

Re:Question: Why WMA?

[Brett Glass]

The answer to this question is simple. Many streaming media sites use Windows Media because the server is given away for free and does not limit the number of streams you can serve (unlike RealNetworks' products, where you pay by the number of streams). Webcasters, already squeezed by huge fees from the RIAA, unions, etc., don't want to pay high prices for the streaming software. So, they go with Microsoft's free server. And you, if you want to listen to their programming, must have a CODEC that lets you listen to a Windows Media stream.

As mentioned elsewhere in this topic, the fact that the CODEC mentioned here is licensed under the LGPL is likely to prevent its use in players for some operating systems, which is a shame. Whether or not we like Microsoft or Windows Media, I think you'll agree that all authors of players, and all end users, should be able to play streams that are encoded in that format.

Most complete grabber? We're in big trouble then.

[Trogre]

ffmpeg is great for video streams, and even sound streams. Just don't try doing both at once.

I have had *zero* luck trying to get the audio track to sync with the video, even at insanely low resolutions (eg half PAL) with no frame drop. Different combinations of different codecs make little difference it seems.

The FAQ even says so:
4) I get audio/video synchro problems when grabbing.

Currently, the grabbing stuff does not handle synchronisation
correctly. You are free to correct it. It is planned to fix it ASAP

So IMHO, ffmpeg as it stands is completely useless as an audiovisual grabber.