- From: Mark Watson <watsonm@netflix.com>
- Date: Wed, 12 Jun 2013 21:47:23 -0700
- To: Duncan Bayne <dhgbayne@fastmail.fm>
- Cc: "public-restrictedmedia@w3.org" <public-restrictedmedia@w3.org>
Sent from my iPhone On Jun 12, 2013, at 9:06 PM, Duncan Bayne <dhgbayne@fastmail.fm> wrote: > 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. Actually, we're not aware of any requirements from content providers for DRM protection of subtitles/captions. All our subtitles/captions are delivered in the clear today. ...Mark > >> 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 > > I usually check my mail every 24 - 48 hours. If there's something > urgent going on, please send me an SMS or call me at the above number. >
Received on Thursday, 13 June 2013 04:47:53 UTC