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Re: Encrypted Media proposal: Summary of the discussion so far

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Thu, 8 Mar 2012 14:12:38 -0800
Message-ID: <CAAWBYDBX96BvQgkHABX+x0zVeaGrckOedN+PUi5NqpPgWtySYg@mail.gmail.com>
To: Glenn Adams <glenn@skynav.com>
Cc: Philip J├Ągenstedt <philipj@opera.com>, public-html@w3.org
On Thu, Mar 8, 2012 at 2:04 PM, Glenn Adams <glenn@skynav.com> wrote:
> On Thu, Mar 8, 2012 at 12:54 PM, Tab Atkins Jr. <jackalmage@gmail.com>
> wrote:
>> On Thu, Mar 8, 2012 at 8:13 AM, Glenn Adams <glenn@skynav.com> wrote:>
>> Thirdly, your claim "a necessary side-effect, makes it impossible to provide
>> > accessibility improvements like brightness/contrast controls or audio
>> > filtering" is factually wrong.
>>
>> Please explain how it is possible to provide accessibility
>> improvements like this if the DRM component controls the entire
>> rendering pipeline, providing the video to the browser as an overlay.
>
> There is nothing in the proposal that mandates any of:
>
> (1) "the DRM component controls the entire rendering pipeline"
> (2) "providing the video to the browser as an overlay"

That was given as a reasonably possible DRM component that a movie
distributor might require, and neither you or Mark has stated
definitely that it's not a possibility.


> If what you say is true, then the same comment would equally apply to
> canvas.getContext().

Um, what?


> The facts are that whether or not (1) or (2) is true depends on (A) how the
> browser implements the proposal, the media pipeline, and video frame
> compositing, and (B) what control features the browser is willing to
> delegate to a CDM instance.
>
> A browser implementer may choose (A) or (B) based on their own criteria,
> which is not specified in the proposal. Some browsers may choose (A) or (B)
> in a manner that precludes the use of certain CDMs. That's fine, and that's
> outside the scope of the proposal as far as I'm concerned. That is a
> business decision that should not be dictated by a W3C specification.

Once again, if a video distributor requires a CDM that does this (and
you continue to suggest this is a possibility), then it's a de facto
part of the proposal.  The fact that this is a possibility is a strike
against the proposal.

~TJ
Received on Thursday, 8 March 2012 22:13:26 GMT

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