HTML WG media telecon 2013-10-01

http://www.w3.org/2013/10/01-html-media-minutes.html

Apologies - I scribed but neglected to send out the link to the minutes

John


________________________________

[W3C]<http://www.w3.org/>

- DRAFT -
HTML Media Task Force Teleconference
01 Oct 2013

Agenda<http://lists.w3.org/Archives/Public/public-html-media/2013Oct/0000.html>

See also: IRC log<http://www.w3.org/2013/10/01-html-media-irc>

Attendees
Present
Regrets
Chair
SV_MEETING_CHAIR
Scribe
johnsim
Contents

  *   Topics<http://www.w3.org/2013/10/01-html-media-minutes.html#agenda>
     *   Roll Call<http://www.w3.org/2013/10/01-html-media-minutes.html#item01>
     *   previous minutes<http://www.w3.org/2013/10/01-html-media-minutes.html#item02>
     *   charter revision<http://www.w3.org/2013/10/01-html-media-minutes.html#item03>
     *   CfC for EME heartbeat<http://www.w3.org/2013/10/01-html-media-minutes.html#item04>
     *   Encrypted Media Extensions Bugs<http://www.w3.org/2013/10/01-html-media-minutes.html#item05>
     *   bugs for discussion/feedback<http://www.w3.org/2013/10/01-html-media-minutes.html#item06>
  *   Summary of Action Items<http://www.w3.org/2013/10/01-html-media-minutes.html#ActionSummary>

________________________________

<trackbot> Date: 01 October 2013

<paulc> trackbot, start meeting

<trackbot> Meeting: HTML Media Task Force Teleconference

<trackbot> Date: 01 October 2013

<paulc> Open bug summary: http://lists.w3.org/Archives/Public/public-html-media/2013Oct/0001.html
Roll Call
previous minutes

no comments
charter revision

paulc: everyone needs to rejoin the working group
... have 45 days to decide

<paulc> Rejoin request: http://lists.w3.org/Archives/Public/public-html-admin/2013Oct/0000.html

<paulc> rejoin link: http://www.w3.org/2004/01/pp-impl/40318/join

paulc: go to the page, ping your AC Rep by following the link.
CfC for EME heartbeat

closes today. So far no substantive objections, closes midnight Boston time
Encrypted Media Extensions Bugs

<paulc> See: http://lists.w3.org/Archives/Public/public-html-media/2013Oct/0001.html

Paulc: this is David's analysis

<paulc> http://tinyurl.com/7tfambo

<paulc> 21 bugs

paulc: the history here, is that objection to CfC, to point to something broken in the heartbeat document, technical comments don't block, and these three bugs came from that type of response.
... are these duplicates?

markw: i do not believe they are duplicates

<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=23340

<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=23341

<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=23342

ddorwin: should we remove the goals section, introduction to "here is what this does" and not sure it fits in the spec anymore

paulc: let these rest for right now, but could you put that as comments on 23341 and 23342

<joesteele> +1 to removing the goals

<paulc> We'll leave this new bugs for now and return to these.
bugs for discussion/feedback

<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=21854

adrianba: when i added the state transitions, three issues left unresolved, wanted to see if any more concrete feedback, and so this morning i replied...
... in David summary, three resolutions:
... key added, not clear under what circumstances it should fire - proposal is to remove

<ddorwin> +1 to remove keyadded

adrianba: way of interrogating what state it is in, but no general interest in this so okay to remove for now

<ddorwin> +1 to deferring the state attribute unless/until we need it.

adrianba: previous discussed transition from ready state to error state, was not clear when doing the editing under what circumstances that would be needed

during playback, if you wanted to fire a key message, not clear if there is a reason to fire against the session or a playback error, so i am proposing to do nothing unless someone can propose text

markw: i think the state variable could be useful for debugging

adrianba: that was kind of why i proposed it, but when it came to updating the spec i had a consensus of people who agreed

joesteele: two questions - i was one of the people arguing against the state variable, because we thought we could calculate state from application
... how would you handle case of output protection failure during playback? against media key session

<markw> @joesteele - I agree the app can calculate it, but having it explicit allows you to assert on whether the state is what you think it is - useful both for app debugging and UA testing

adrianba: only errors against media key session are related to communication with the license server to acquire keys
... original reason for session was to correlate messages - so violation of output protections should be fired against the media elements

joesteele: error codes on media element?

<adrianba> https://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/encrypted-media.html#dom-media_err_encrypted

adrianba: i thought we added media error encrypted - should fire when error with playback related encryption

joesteele: should we not add this for the video tag?

adrianba: this is an extension spec, so defined as an extension

ddorwin: encrypted media and I cannot play it. Media errors are fatal to playback.
... other than i don't know how to play this media, - as to where to add them, everywhere you can fire an error - probably say if there is some error fire a media key error

adrianba: first comment - if there is an examp;le of an error that fires in this state which is not terminal to playback, i would like to understand that a little better
... in our implementation we determined that most of these "during playback error conditions" occurs has no correlation to a particular session
... so we actually - meant we couldn't continue playback, so we use encrypted media error for this, only against sesssion when it is specifically session related

<paulc> ac joe

adrianba: ready to error okay, but need text proposal

joesteele: output protection and domain error are two examples - domain - in a blackout situation, live stream i don't have rights for (part of)
... one way is key error to force a new license acquisition
... key rotation and license rotation - key is standard CAS model, minute or five minutes for - license rotation stream has ... different licensing group
... signalling a domain in the non-CENC case

ddorwin: we have some - this change depends on clarity on key errors - maybe we should add it to that

paulc: if we did that, adrian, could we close this bug

<joesteele> +1 to removing the key added and moving the other issue to the remaining error code bug

paulc: the answer to "remove key added" and "not adding a state variable" are okay, and ready to error added as a new bug

adrianba: propose adding to 21798

<paulc> Update 21798 with third item

<paulc> Therefore after updating the spec we can close out 21854 with the addition of the error code item to 21798.

paulc: next item for topics, 19809

<ddorwin> https://www.w3.org/Bugs/Public/show_bug.cgi?id=19809

<joesteele> https://www.w3.org/Bugs/Public/show_bug.cgi?id=19809

<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=19809

ddorwin: part of the problem is whether to fire "key added", perhaps move Adrian's action on key added to this bug
... removed key added and that was the important thing
... remove all text when adding keys or events fired when adding keys

<paulc> David will re-evaluate 19809 after Ade's changes 21854 are completed.

<paulc> Bug 17202

https://www.w3.org/Bugs/Public/show_bug.cgi?id=17202

joesteele: agree with intent of David's comment but runs contrary to the ability - you want to share keys to have a performant implementation
... not sure how to solve but i don't think we want to be explicit about preventing it

adrianba: question how this bug relates to 21855

<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=21855

joesteele: i was okay with what you proposed, my interpretation was it is allowed but not required to directly transition to the key ready state

adrianba: two parts to my proposal - yes, allowed but not required - but second part, only optimization we call out and if you have two sessions which are related to fundementally the same key once you got to the ready state

if further need to interact - no further optimization - so we don't have to deal with the complex questions david asked

ddorwin: my view of these two bugs - 855 being this optimization, mainly related to the same page, same init data multiple times,
... that is where we are avoiding network traffic, not the "i saved this key" case
... there is a clear leakage of information if you use a domain key the application is storing - so i would like to see Joe propose a way to do domain keys that avoids leaking information

paulc: but that is a response to 202?

joesteele: i will come up with some proposal there, my counter to that would be in all the situations - many - except some pathological situations

when you have a domain key susceptible to the kind of sharing you have mentioned - can be shared on client or server

<paulc> ACTION: joesteele to propose text for bug 17202 to propose how to share keys without leakage of information [recorded in http://www.w3.org/2013/10/01-html-media-minutes.html#action01]

<trackbot> Error finding 'joesteele'. You can review and register nicknames at < http://www.w3.org/html/wg/media/track/users>.<http://www.w3.org/html/wg/media/track/users%3E.>

paulc: would like an action - propose how to share keys without leakage of information

<adrianba> ACTION: joe to propose text for bug 17202 to propose how to share keys without leakage of information [recorded in http://www.w3.org/2013/10/01-html-media-minutes.html#action02]

<trackbot> Created ACTION-40 - Propose text for bug 17202 to propose how to share keys without leakage of information [on Joe Steele - due 2013-10-08].

<adrianba> ACTION-40 due 2013-10-15

<trackbot> Set ACTION-40 Propose text for bug 17202 to propose how to share keys without leakage of information due date to 2013-10-15.

<paulc> Bug 17682

paulc: next is https://www.w3.org/Bugs/Public/show_bug.cgi?id=17682

<ddorwin> specific comments: https://www.w3.org/Bugs/Public/show_bug.cgi?id=17682#c11

paulc: walk through one at a time

ddorwin: 1 is JWK versus JWK set
... mention key ID in the text - that they are base64 encoded, padded, and then more confusing one is the encoding
... it seems ASCI compatible compatible encoding means multiple things

adrianba: this is right out of the HTML5 spec, link to the definition of it in the HTML5 spec

<adrianba> http://www.w3.org/TR/html5/infrastructure.html#ascii-compatible-character-encoding

ddorwin: definition is where we got confused - seemed overly complex

paulc: difference of opinion - define by reference or inclusion -
... david's question is more a technical one - don't agree with the reference - can someone give a pointer to where this is in the spec

<adrianba> https://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/encrypted-media.html#simple-decryption-clear-key

paulc: so you are challenging the reference - so David is questioning whether this is the right reference

<ddorwin> there are 12 instances of "ASCII-compatible character encoding" in http://www.w3.org/TR/html5/single-page.html. All seem related to input or metadata.

adrianba: i guess my overall thought on this bug is that some very specific proposal that David has on implementation experience, make these changes and point fix our way
... propose - i am happy with this and take another look at the ASCII compatible encoding but not block on this

<ddorwin> http://tools.ietf.org/html/draft-jones-jose-json-private-and-symmetric-key

ddorwin: number six we didn't get to- linked IETF document is expired - Jason Private Key -

adrianba: documents have a lifetime of six months, goes away, look to see if we need to push it forward in the IETF

ddorwin: document as an issue?

paulc: would the task force worth while sending Mike Jones a note asking status of this draft?
... before we run out of time, go back to the question i asked that adrian answered before I asked - any objection to David implementing changes he proposed in 17682?

<joesteele> no objection

<paulc> Bug 17750 was next on the list

<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=17750

adrianba: highlight 17750 - that we didn't get to - i added comments - this is about the close method - proposed an amendment on state transition to deal with close and deals with mark's outstanding issue on key release

<paulc> Possibly related to Mark's work on 17199

<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=17199

Summary of Action Items
[NEW] ACTION: joe to propose text for bug 17202 to propose how to share keys without leakage of information [recorded in http://www.w3.org/2013/10/01-html-media-minutes.html#action02]
[NEW] ACTION: joesteele to propose text for bug 17202 to propose how to share keys without leakage of information [recorded in http://www.w3.org/2013/10/01-html-media-minutes.html#action01]

[End of minutes]
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Minutes formatted by David Booth's scribe.perl<http://dev.w3.org/cvsweb/~checkout~/2002/scribe/scribedoc.htm> version 1.138 (CVS log<http://dev.w3.org/cvsweb/2002/scribe/>)
$Date: 2013-10-01 16:01:35 $
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Agenda: http://lists.w3.org/Archives/Public/public-html-media/2013Oct/0000.html



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Found Date: 01 Oct 2013

Guessing minutes URL: http://www.w3.org/2013/10/01-html-media-minutes.html

People with action items: joe joesteele


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________________________________
John C. Simmons | Media Platform Architect | Microsoft Corporation | direct 425-707-2911 | mobile 425-269-5759