RE: {agenda} HTML WG media telecon 2014-09-23 - EME status and bug discussion

I have another topic for the agenda, Paul:  Allowing license servers and CDMs to control data persistence and secure release.  I will open a bug on this, but also want to attach the topic directly to your agenda.

Our current spec uses sessionType to control storage of session data, and load() and remove() to support secure release.  These assume the app is in control of the secure release process, and in many respects, the CDM need not be aware.  Unfortunately, these features don't work well with implementations that have the license server and CDM control secure release using terms set in the license itself.  This license server model has many positives.  It can securely manage license persistence, expirations and secure release features, directly and with little app complexity.  We believe supporting it will be important for EME; however, there are issues between it and the current spec:


1.      At most, sessionType could only be a hint to the process in the license controlled model, as the license terms would determine whether the license itself is stored, and whether it is subject to secure release requirements.

2.      Load() is problematic, since licenses under secure release may still be temporary (in fact this may be desirable) and may be released even though secure release messages are still pending.

3.      Status information on secure release is maintained in the CDM and currently would be inaccessible to applications.  We could make this information accessible, but the utility of any function we provide for this might vary by CDM.

Some of these issues result from overloading the original intents for MediaKeySession and sessionId.  These originally managed the short term exchange of messages and have grown to now manage the lifetime of media content playback on a given device.  The original short term intention was a much better fit with license server controlled CDM implementations.

We believe the license server controlled model must be supported by EME.  I'd like to get agreement on this and discuss whether it can be done with a common EME abstraction or not.

Jerry

From: Paul Cotton [mailto:Paul.Cotton@microsoft.com]
Sent: Sunday, September 21, 2014 7:01 AM
To: public-html-media@w3.org
Subject: {agenda} HTML WG media telecon 2014-09-23 - EME status and bug discussion


The HTML WG media teleconference meeting will occur on 2014-09-23 for up to 60 minutes from 15:00Z to 16:00Z.



http://timeanddate.com/s/2qyj



Tokyo midnight, Amsterdam/Oslo 17:00, London/Dublin 16:00, New Jersey/York 11:00, Kansas City 10:00, Seattle/San Francisco 08:00.



Chair of the meeting: Paul Cotton

Scribe: TBD



(See the end of this email for dial-in and IRC info.)



== Agenda ==



1. Roll call, introductions and selection of scribe



2. Previous meeting minutes

Sep 9:

http://lists.w3.org/Archives/Public/public-html-media/2014Sep/0005.html

Aug 26:

http://lists.w3.org/Archives/Public/public-html-media/2014Aug/0030.html

Aug 19:

http://lists.w3.org/Archives/Public/public-html-media/2014Aug/0018.html



3. EME status and bugs



a) Encrypted Media Extensions editor's draft http://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/encrypted-media.html

Last updated on Sep 15.



b) Encrypted Media Extensions bugs:

http://tinyurl.com/7tfambo

Status as of Sep 21: 18 bugs

Status as of Sep 15: 18 bugs

Status as of Sep 8: 20 bugs

Status as of Aug 25: 18 bugs



5.  New EME bugs since the last meeting



a) Bug 26776 - Diagnosing and resolving CDM errors needs a numeric systemCode (deleted with MediaKeyError)

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26776#c1

Status:  See Mark's question and the answer at:

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26776#c5

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26776#c6



b) Bug 26811 - Separate definitions of Initialization Data Types from Stream Format parsing

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26811

Status: Spun off from discussion of:

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26738



6. Security related bugs



a) Bug 26332 - Applications should only use EME APIs on secure origins (e.g. HTTPS)

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26332

Status: See post from TAG about their work on a TAG finding:

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26332#c78

See also the next bug which deals with some of the InitData items:

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26332#c77



b) Bug 26838 - Normatively address vulnerabilities related to initData contained in media data

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26838#c2



7. Other EME bugs



a) Bug 26738 - "ISO Common Encryption EME Stream Format and Initialization Data" should be extended for MPEG-2 TS CENC

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26738

Status: I think we have dealt with the Patent Policy question and can now return to the original technical request.



b) Bug 25092 - Need a way to inform script that resolution restrictions are applied

https://www.w3.org/Bugs/Public/show_bug.cgi?id=25092

Status: See:

https://www.w3.org/Bugs/Public/show_bug.cgi?id=25092#c22



c) Bug 25923 - isTypeSupported should be asynchronous

https://www.w3.org/Bugs/Public/show_bug.cgi?id=25923

Status: See recent discussion since last meeting and David's proposal in:

https://www.w3.org/Bugs/Public/show_bug.cgi?id=25923#c32



d) Bug 26372 - Report issues/events not related to a specific method call

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26372

Status: See recent discussion since last meeting.



e) Bug 24771 - Provide guidance on object and CDM lifetime (including when events are guaranteed to be fired)

https://www.w3.org/Bugs/Public/show_bug.cgi?id=24771#c5



8. Other EME bugs

http://tinyurl.com/7tfambo



9. Any other business



10. Chair and Scribe for next meeting



11. Adjournment



== Dial-in and IRC Details ==



Zakim teleconference bridge:

   +1.617.761.6200, conference 63342 ("media")

https://www.w3.org/Guide/1998/08/teleconference-calendar#s_5366



Supplementary IRC chat (logged):

   #html-media on irc.w3.org port 6665 or port 80 Paul Cotton, Microsoft Canada

17 Eleanor Drive, Ottawa, Ontario K2E 6A3

Tel: (425) 705-9596 Fax: (425) 936-7329



Paul Cotton, Microsoft Canada

17 Eleanor Drive, Ottawa, Ontario K2E 6A3

Tel: (425) 705-9596 Fax: (425) 936-7329