Re: Accessibility and EME (was RE: Is EME usable regardless of the software/hardware I use ?)

John,

Thanks for your detailed reply.

> This is not entirely correct, and with regard to media is a non-issue.  

Agreed - my concern was around non-media content like text.  It sounds
like you & the accessibility folks have media controls well covered.

> Screen reading tools used by the blind and low-vision user essentially
> interacts with the DOM (or a virtual snapshot of that DOM, depending on
> the
> tool), and so anything that is in the DOM is "shifted" to an alternative
> output mode: text is rendered via either a speech output or Braille
> output
> device via the Accessibility APIs of the different operating systems. 
> Blind
> users however will be able to hear the encrypted videos audio stream
> exactly
> like you will if you (or they) are using a device that supports the
> decryption of the media stream. 

This is the area of accessibility tech. that I'm more familiar with, and
it's the core of my accessibility concern w.r.t. CDMs.  My understanding
is that text protected by a CDM will not be accessible through the DOM,
and thus will be inaccessible to screen reading tools. 

The CDM can choose to provide a clear-text stream for use by such a
device, but in the case of text, wouldn't that be exactly equivalent to
the protected content in the first place?  It seems unlikely to me that
such a solution would seem acceptable to content providers, but as
you've correctly pointed out, you have far greater experience &
knowledge in this area.

> So you were basically wrong about *all* of that, from understanding how
> Assistive Technology actually works, to *any* of the potential accessibility
> issues of "HTML5 Media", as well as initially expressing this as an issue
> for "physically disabled" users. It did not go un-noticed to me that you
> then attempted to try and make this a screen-reader issue/problem (which it
> really isn't either). 
> 
> My accusation of FUD stands, and my frustration and outright anger of you
> attempting to invoke "accessibility" as a justification for not working
> on EME is, to my mind, unconscionable. This is not the first time I've
> encountered others attempting to "play the accessibility trump card" with
> little-to-zero knowledge or understanding of the real issues, but, what
> the heck, who is actually going to *oppose* accessibility and "doing the
> right thing", so it's an easy point to score, right? Right.

I mentioned screen-readers because they are the assistive technology
with which I'm most familar.  And, as I explained above, I'm still a
little uncertain as to how screen-reader integration with EME / CDM -
protected text (not video or audio content!) - would work in practice.

Even given that concern, I'm quite happy to amend my statement to:

"The *sole* purpose of EME is to interop with closed-source proprietary
blobs called CDMs.  These will most assuredly not be available to all
people regardless of hardware, software, network infrastructure, and
geographical localtion.  They will probably not cater for those who
speak non-mainstream languages."

Would that satisfy you?

-- 
Duncan Bayne
ph: +61 420817082 | web: http://duncan-bayne.github.com/ | skype:
duncan_bayne

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Received on Thursday, 13 June 2013 04:06:44 UTC