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Re: Encrypted Media proposal (was RE: ISSUE-179: av_param - Chairs Solicit Alternate Proposals or Counter-Proposals)

From: Boris Zbarsky <bzbarsky@MIT.EDU>
Date: Mon, 27 Feb 2012 17:46:15 -0500
Message-ID: <4F4C07B7.5030506@mit.edu>
To: Mark Watson <watsonm@netflix.com>
CC: "<public-html@w3.org>" <public-html@w3.org>
On 2/27/12 5:35 PM, Mark Watson wrote:
> Maybe technically, in principle, yes. But the Adobe web site lists specific versions of desktop browsers for specific platforms that are "supported" and specific devices that are "certified". And it isn't supported unless it's tested. Even if the full Flash test suite was available from Adobe then a new browser maker would still need to work with Adobe to fix any bugs and get onto their "supported" or "certified" list.

That's true, but being on that list is not a prerequisite for actually 
having a working Flash...

> My (albeit limited) experience with NPAPI suggests that just implementing from the specification probably isn't enough to have something as complex as Flash "just work".

That's almost certainly true; there are some edge cases that might be 
underdocumented.

But again, there are no legal restrictions preventing someone from 
looking at one of the two existing open-source codebases that have an 
NPAPI implementation that works with Flash and adjusting their 
implementation accordingly.

>>> With our proposal, the new browser would need instead to support one or more Content Decryption Modules.
>>
>> Right; the question is what that would actually entail.
>>
>>> This is a much simpler task over which the new browser developer has greater control and more options.
>>
>> That's not obvious a priori.  I'd love to understand why this is the case.
>
> It's simpler because the functionality in a CDM is a very small subset of the functionality in a plugin like Flash or Silverlight.

Unless I'm missing something, implementing a CDM without explicit 
permission from whoever controls it is likely to fall afoul of the 
anti-circumvention provisions of the DMCA, at least in the United 
States.  _Am_ I missing something?

> The engineering costs to create and maintain a CDM is much less than the engineering effort to create and maintain a full-featured plugin like Flash or Silverlight.

Implementing the browser side of NPAPI is nothing like creating or 
maintaining Flash or Silverlight.

> The licensing issues are no worse

I don't see why.  I'd love to understand that.

> Companies interested in commercial video services might be motivated to create and distribute CDMs when they would not be interested in creating and distributing full-fledged plugins.

No one is asking them to create and distribute such plug-ins; the 
plug-ins are already there.

I feel like we're talking past each other here....

> These are obviously fairly general statements - the proposal doesn't prescribe a model for where CDMs will come from and we appreciate opinions and ideas on that topic.

OK, let's try a concrete example.

Assume this system is implemented and working as desired.

What does a new browser codebase on Windows, say, have to do to end up 
being able to watch video provided by commercial video services?

How does the answer change if the operating system is Linux?  How does 
it change if it's a new operating system?  How does it change if it's a 
new hardware architecture?

I realize that even existing use of Flash is a problem in those last 
three cases, of course, but I'm worried about even the first case here. 
  Again, I am not a lawyer, all the standard disclaimers.

-Boris
Received on Monday, 27 February 2012 22:46:45 UTC

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