W3C

- DRAFT -

HTML Media Task Force Teleconference

04 Mar 2014

Agenda

See also: IRC log

Attendees

Present
paulc, markw, glenn, joesteele, adrianba, +1.425.936.aaaa, ddorwin, davide, johnsim, pal, BobLund, jdsmith
Regrets
Chair
Paul Cotton
Scribe
Adrian Bateman

Contents


<trackbot> Date: 04 March 2014

<paulc> Agenda: http://lists.w3.org/Archives/Public/public-html-media/2014Mar/0010.html

<scribe> Agenda: http://lists.w3.org/Archives/Public/public-html-media/2014Mar/0010.html

<scribe> ScribeNick: adrianba

<scribe> Scribe: Adrian Bateman

Roll call, introductions and selection of scribe

paulc: done

NEW EME bugs since the last meeting

paulc: there are 4 of these
... one of them had a lot of discussion but the others not so much

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

<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=24771

paulc: long proposal here - do you just want to add this to the list of things of comments or should david introduce the issues?

ddorwin: issue came up when deciding when to GC the objects - could be a circular reference meaning things wouldn't get collected

paulc: volunteer to review?

<markw> I will review it too, but I am also not a browser vendor

joesteele: i could review but not sure if my input would be as useful - not a browser vendor

paulc: perhaps someone from Microsoft can take a look at this

Bug 24873 - Current isTypeSupported() definition does not provide sufficient information to applications

https://www.w3.org/Bugs/Public/show_bug.cgi?id=24873

paulc: filed recently - does this fall into the same category?

ddorwin: not being able to detect if the browser has capabilities needed - adrian mentioned this in one of the other bugs

<joesteele> +q

ddorwin: first two paragraphs says what it is - the rest says why
... two changes - one if to add capability string and the other is changing the return type to have three states
... somewhat like canPlayType though doesn't have to be
... those are independent but work well together

joesteele: seems to reintroduce something we discussed at the beginning
... decided early on the key systems shouldn't have this info because it was too complicated

ddorwin: some of the same issues but this is more targeted specifically at audio vs video
... but we decided not to 'abuse' the key system name

joesteele: maybe i'm not understanding capability - do you mean things like HDCP
... is this something where this platform is not at all capable or not right now
... because if not right now then you'd need to call again

ddorwin: no, i wasn't thinking about HDCP which can take a couple of seconds
... this is supposed to return quickly
... many key systems support multiple levels of robustness

<ddorwin> The old capability detection bug: https://www.w3.org/Bugs/Public/show_bug.cgi?id=16611

adrianba: not sure what the capability string contains - what if it is more than one thing - should it be a string or something else?

ddorwin: it is key system specific - could have a key system specific separator
... could have an array of strings but just as easy to be comma separated

Bug 24874 - Positive isTypeSupported() may be misleading (MSE vs. .src=)

https://www.w3.org/Bugs/Public/show_bug.cgi?id=24874

ddorwin: result of isTypeSupported doesn't say if it works with MSE or with src=
... filed to track this issue

paulc: questions?

Bug 24904 - Uint8Array parameters should not be modifiable after method calls return

https://www.w3.org/Bugs/Public/show_bug.cgi?id=24904

paulc: provided the beginning of the march part of the thread

http://lists.w3.org/Archives/Public/public-html-media/2014Mar/0002.html

paulc: most recent suggestion to raise this as a TAG issue

<joesteele> +1 to email discussion

paulc: shall we let this continue in email? this problem exists in other places too

EME bugs for discussion

paulc: all the bugs that had postings since our last meeting
... agenda item 7 includes implemented bugs since last time (4 bugs)
... agenda item 8 is bugs waiting for editors (6 bugs)
... agenda item 9 is low pri bugs
... plan to step through the items in #6 and ignore the others today

Bug 17673 - Define Initialization Data for implementations that choose to support the ISO Base Media File Format

https://www.w3.org/Bugs/Public/show_bug.cgi?id=17673

adrianba: we think we should move ahead with changing this as discussed in recent meetings to see if people like the text
... (that's Microsoft's position)

<joesteele> no objection

paulc: any comments?
... any objections to trying this out?
... okay, this one is assigned to the editors to do

adrianba: i'm happy to make the change

ddorwin: i'll file a specific bug about the "CENC" string - i suspect we'll need to change isTypeSupported too

Bug 17750 - Define the behavior MediaKeySession close() and clearing the keys attribute

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

paulc: comment from adrian on feb 21

<joesteele> +q

adrianba: we reviewed this and think we're proposing the correct answer - we need someone to check our working

ddorwin: no specific objections

markw: looks okay - i will check with our implementers

joesteele: i had raised a question above about cached keys being released
... not clear to me that we agree that keys can be cached
... might be off topic for this bug

adrianba: i think loadSession implies there are cached keys otherwise what could you load
... i think there is a question beyond just consistency with other specs - we proposed a solution that does impact what order things can execute in
... so there is something EME specific to review here too

glenn: haven't looked at the detail but curious if there is a need for promises here?

<ddorwin> Does the proposed spec change related to spinning the event loop mean MediaKeys construction will prevent any other tasks (from any other spec) from being processed? Is that desirable?

adrianba: i don't think promises apply here - this is about multiple async tasks interacting with each other

<glenn> sleep(0)

adrianba: spinning the event loop is like VB6 DoEvents - it lets other things run

paulc: is there an editor to implement this?

adrianba: i can do this

Bug 21798 - Revisit MediaKeyError codes

https://www.w3.org/Bugs/Public/show_bug.cgi?id=21798

adrianba: we can live with not solving this in this version but if someone comes up with a workable proposal then we are okay with that

ddorwin: i will make a proposal

Bug 23619 - Change MediaKeyError to extend DOMError and use strings for error names

https://www.w3.org/Bugs/Public/show_bug.cgi?id=23619

<ddorwin> Open issue in DOM4 on the future of DOMError: http://www.w3.org/TR/dom/#interface-domerror

adrianba: while the spec continues to have DOMError, we think we're using it correctly
... we also prefer to keep systemCode

<joesteele> +1 to keeping it in the spec as-is

ddorwin: i don't object to system code and the inclusion requires that we define an additional type - if people want to keep it then that is fine - it is already in the spec

paulc: what is next?

ddorwin: if nobody wants to eliminate this type then we resolve, fixed

paulc: proposal is to mark it fixed

<ddorwin> done

Bug 24027 - Define a generic Initialization Data solution for ISO Base Media File Format and/or Common Encryption (will be used by Clear Key)

https://www.w3.org/Bugs/Public/show_bug.cgi?id=24027

paulc: mark agreed to add a concrete proposal - in comment 6
... some dialogue here - what is the current state?

markw: i didn't see the questions from joe and david so i need to catch up and reply to their points

joesteele: i should reply in the bug - i wasn't clear from david's last question why you wouldn't want to use the MAC - i would guess that the CDM would say key not available

ddorwin: some confusion about what the MAC was earlier in thread - agree - question is do the existing algorithms deal with this

Bug 24419 - Clear Key: Define license request format

https://www.w3.org/Bugs/Public/show_bug.cgi?id=24419

paulc: is this ready to move to the "to be implemented" list?

ddorwin: need to implement the license request format first

Bug 24673 - Make all content type string checks case-sensitive

https://www.w3.org/Bugs/Public/show_bug.cgi?id=24673

ddorwin: we find that the content type and the codecs have different requirements
... so we might need non-normative text

adrianba: seems fine - just need text to add

paulc: do we need concrete text in the bug or just move forward - better to move ahead

ddorwin: will make this dependent on the "CENC" bug that I said I will file

Any other business

paulc: i said we'd skip the other bugs unless someone objects - now is the time if you want to
... in 10 days i'll evaluate where we stand for the topic bugs for discussion in the next meeting

adrianba: different topic, are people planning to attend the F2F meeting to discuss EME?

<markw> yes, I'll be there

<BobLund> I'll be there

paulc: [lists attendees from TF who already plan to attend]

<paulc> https://www.w3.org/2002/09/wbs/40318/html-april-2014/results

paulc: if you can't attend might be helpful to fill out the registration form saying so

joesteele: i may have a conflict - probably be on the phone at least

ddorwin: would be nice if we knew which day to minimise travel

<paulc> https://www.w3.org/wiki/HTML/wg/2014-04-Agenda#Potential_Topics

paulc: if you put it on the potential topics list then we can reserve that time
... meeting is tues/wed

<BobLund> Tue or Wed AM

<paulc> April 8-9

paulc: does anyone have a pref for which day

johnsim: if the meeting is wed AM i might be able to attend

paulc: any objections to wed AM?

<BobLund> Wed AM is good

adrianba: works for me

paulc: would it be worth asking dsinger about attending?

pal: excellent idea

paulc: i'll propose on the draft agenda - should i ask for 9 to 11?
... i'll figure this out

Adjournment

paulc: talk to you in 2 weeks

Summary of Action Items

[End of minutes]

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Guessing input format: RRSAgent_Text_Format (score 1.00)

Found ScribeNick: adrianba
Found Scribe: Adrian Bateman
Default Present: paulc, markw, glenn, joesteele, adrianba, +1.425.936.aaaa, ddorwin, davide, johnsim, pal, BobLund, jdsmith
Present: paulc markw glenn joesteele adrianba +1.425.936.aaaa ddorwin davide johnsim pal BobLund jdsmith
Agenda: http://lists.w3.org/Archives/Public/public-html-media/2014Mar/0010.html
Found Date: 04 Mar 2014
Guessing minutes URL: http://www.w3.org/2014/03/04-html-media-minutes.html
People with action items: 

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