Comments on: New release of gnome-themes-extras

By: Mike Hearn

Mike Hearn — Wed, 30 Nov -0001 00:00:00 +0000

I don’t think you can support DRM *playback* with GStreamer 0.10 and todays Linux kernel.

I mean, if you have a theoreticaly wmdrm-decoder element that knows how to decrypt WMA files, what’s to stop you doing:

filesrc location=britney.wma ! wmdrm-decoder ! oggenc ! filesink location=britney.ogg

And stripping the DRM that way? The element would have to scan the entire pipeline and prove to itself that the audio is going direct to the kernel and not being teed off to any files or network streaming elements anywhere. And that’s not possible to do because anybody can write their own element that the wmdrm-decoder element wouldn’t recognise that subverts the pipeline that way.

I really think you guys need to research how the existing crop of DRM systems work – maybe the very lightweight ones like FairPlay can be supported (but apple have zero incentive to help a competitor that way) but there’s absolutely zero chance of you supporting Windows Media which is pretty much the de-facto DRM system outside of Apple land.

In particular, Windows Media playback requires a kernel that refuses to load unsigned drivers and which cannot be modified at will by the user …. it’s called the Secure Audio Path and is implemented in Windows XP and ME.

By: Mike Hearn

Mike Hearn — Wed, 30 Nov -0001 00:00:00 +0000

Oh … I didn’t finish the comment. Obviously DRM playback on Linux is hard to impossible simply because open source and DRM have competing philosophies (it’s not like encryption at all) but DRM *encoding* probably is possible.

So I guess there’s no reason you couldn’t support protected radio streaming and the like using something like WMDRM.

By: Christian Schaller

Christian Schaller — Wed, 30 Nov -0001 00:00:00 +0000

Mike, the essence of the design is the design of a secure pipeline. The decoder would refuse to connect to any plugin it can’t trust if its working with protected content. What happens outside GStreamer is of course a different issue, and here there are work happening at the distros to come up with solutions.

By: Mike Hearn

Mike Hearn — Wed, 30 Nov -0001 00:00:00 +0000

How does it know the plugin is trusted – the binary has to be signed with a trusted key presumably … so how does this work if distros are in charge of compiling GStreamer – they need the trusted key but can’t keep it in their public source packages?

I dunno …. I’ll wait and see what you guys come up with I guess.

By: Xyzzy

Xyzzy — Wed, 30 Nov -0001 00:00:00 +0000

“What happens outside GStreamer is of course a different issue, and here there are work happening at the distros to come up with solutions.”

Would you mind explaining that comment further? What work happening at distros are you referring to?

By: TopDown

TopDown — Wed, 30 Nov -0001 00:00:00 +0000

“How does it know the plugin is trusted – the binary has to be signed with a trusted key presumably … so how does this work if distros are in charge of compiling GStreamer – they need the trusted key but can’t keep it in their public source packages?”

Yes, hence the reason this whole business is fundamentally incompatible with Free software… and Schaller should be ashamed of his umming and ahhing. In case it wasn’t obvious already — he doesn’t actually want to talk about this aspect. He’d rather wave his hands around and talk about how “doors are closed to us if we don’t implement DRM”… and since he’s now sucking on the corporate teat… he’s taken to spouting the corporate line too.