Re: CfC: Create Media Task Force

On 4/15/2012 4:22 PM, Robert O'Callahan wrote:
> On Sun, Apr 15, 2012 at 9:17 AM, Charles Pritchard <chuck@jumis.com 
> <mailto:chuck@jumis.com>> wrote:
>
>     Mark Watson, an editor and proponent of the Media TF asks:
>
>     "Would it be sufficient in this case to be more specific and
>     require that there is at least one interoperable UA implementation"
>
>     Robert O'Callahan replies:
>     "No, I don't think it would... in practice Hollywood requires all
>     sites to use some 'Microsoft CDM' or 'Google CDM' that is only
>     supported by the DRM vendor's browser."
>
>
> What I actually said:
>
>     That would allow a situation where there's Clearkey or some other
>     weak CDM that can be used to demonstrate interoperability, but in
>     practice Hollywood requires all sites to use some "Microsoft CDM"
>     or "Google CDM" that is only supported by the DRM vendor's browser.
>
> Your "creative editing" changed the meaning of what I said from a 
> hypothetical to a bare assertion. That is upsetting. Please refrain 
> from "creatively editing" me again.
>
> I don't believe my objection creates an impasse. I suggested multiple 
> ways to address it, only one of which Mark has rejected so far.

In your statement: What's the distinction between a "weak" CDM and a 
"strong" CDM?
Would a "strong" CDM satisfy your concerns about the allowing "a 
situation" to develop?

I'm sorry that I upset you with my prior editing. Thank you for 
addressing the issue.

---

On your second suggestion:
"Alternatively, for a platform that offers built-in DRM API, you could 
define a CDM that maps onto that API, and explain the mapping in enough 
detail that any UA running on that platform could implement it."

Are you requesting that a "User Agent Implementation Guide" be produced 
by the TF in addition to spec?
What platforms would you expect that document to cover?
http://www.widevine.com/available_platforms.html

Hypothetically, Widevine would publish documents that Opera could use to 
support DRM on the Wii.
In practice, I don't think that'll happen out in the open, without an NDA.
http://www.widevine.com/cwip/index.html

---

Your third suggestion:
"Alternatively, for a proprietary DRM product, you could define a CDM 
that maps onto that product and explain that mapping in enough detail 
that any UA running where that product is present could implement it."

Are you requesting that DRM vendors in the TF be required to publish 
some baseline of documentation?
"A proprietary DRM product" by its nature is not part of the standard. 
Seems like the burden would be on the product vendor to provide 
documentation to implementers.


It doesn't seem to me like those two scenarios would play out in public, 
given the NDAs surrounding DRM.
I've not heard any vendors step up and say that they want to go ahead 
and publish internal documents.

If those won't play out, then that only leaves us with the first idea.


-Charles