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[MEDIA_PIPELINE_TF] minutes - 15 March 2012

From: Kazuyuki Ashimura <ashimura@w3.org>
Date: Fri, 16 Mar 2012 01:14:56 +0900
Message-ID: <4F621580.1090508@w3.org>
To: public-web-and-tv@w3.org
available at:

also as text below.

Thanks a lot for taking these minutes, Juhani!

The next meeting will be held in two weeks, i.e., on March

Due to Daylight Saving, the time should be:
- 15:00Z
- 08:00 US Pacific
- 11:00 US Eastern
- 17:00 Europe
- 24:00 Korea/Japan

Please see also:



       [1] http://www.w3.org/

                                - DRAFT -

                        Media Pipeline Task Force

15 Mar 2012



    See also: [3]IRC log

       [3] http://www.w3.org/2012/03/15-webtv-irc


           Kazuyuki, Clarke, Mark_Watson, Juhani, Kilroy, glenn,
           acolwell, David_Corvoysier, Iraj(?), Joe_Steele,
           Bob_Lund, Jan_Lindquist




      * [4]Topics
          1. [5]Content protection
      * [6]Summary of Action Items

    <Clarke> requirements dashboard:

       [7] http://www.w3.org/2011/webtv/wiki/MPTF

Content protection

    Content protection Req #8 reworded: "Content protection must be
    useable with specific HTML5 features such as media elements
    (and features (such as timed tracks) within these elements)."


    Kilroy: want to be compatible with media source element, new
    Req #13 ?

    Req. #9. "Media element features that are available in an
    implementation must be available for encrypted content as well
    as unencrypted content."

    <kaz> (question by Joe)

    Clarke: Intention is that certain elements are not eliminated
    due to encryption ... like locating ... accessibility ...

    Bob_Lund: Two issues: what source of access to media stream,
    accessibility through various A/V tracks

    Joe: Issue with the proposal ...

    Bob: Enumerate text tracks .... sign, descriptive audio to be
    encrypted etc. ... to be detailed

    Aaron: Text tracks out-of-band not covered by encryption spec

    markW: Agree with the out-band statement by Aaron ...
    ... Open what to do with the issue

    Bob: Describe / identify the tracks in minimum

    Kilroy: Encryption in two levels ....

    out-of-band for the Kilroy part ....

    MarkW: clear key not specified yet where to apply to which

    Clarke: Reqs for out-of-band ... ?

    joe: Limit acceptance of the solution if out-of-band not taken
    into account ... like Caption data
    ... Enough of value to protect

    Joe: Support some of it encrypted

    Bob: Strt and end of trakcs not to encrypt for browsrs to make
    any use of the tracks (captions)

    clarke: discussion to continue, people responses asked for

    <kaz> ACTION: Clarke to work with Bob and modify the text om
    content protection requirement under consideration #9 based on
    today's discussion [recorded in

    <trackbot> Created ACTION-96 - Work with Bob and modify the
    text om content protection requirement under consideration #9
    based on today's discussion [on Clarke Stevens - due

    #10.The particular content protection method required to use
    the content must be identifiable. ---> Change to methods

    <kaz> Kilroy: would propose adding identifiable priority to

    Kilroy: Add: ... prior to downloading the media
    ... metadata before the media

    MarkW: Supported in the proposal
    ... MIME type is not completely descripttive .... answer of
    support is 'probably', not strong 'YES'

    Joe: Link to MIME type extnesions ?

    Will be provided by Mark

    #11.Any parameters required for use of the content protection
    method must be identified and specifiable.

    MarkW: Paramters in the content file itself
    ... scripts independent of protection systems in the proposal
    ... core idea there
    ... What paramters to pass .. please provide examples
    ... CP specific parmaters as a requirement may be more
    difficult ...

    Joe: Enforcement in CDM ... general purpose applications not
    able to use ... ?

    Clarke: Proposal does not violate the req ... but is the req
    useful ?

    Req. #11 to be deleted

    #12.Specific errors relevant to content protections must be
    identified and reportable.

    Req. #12 is according to our previous detailed error


       [9] http://www.w3.org/2011/webtv/wiki/MPTF/HTML_Error_codes



    Is it ?

    MarkW: Earlier errors more on network etc. errors ... still to
    be addressed in LC

    Clarke: #12 to satisfy CP proposal ... ? ---> OK

    #13.The content protection method must be compatible with the
    (new) media source element as described in the adaptive bit
    rate proposal.

    Aaron: Compatibility should not require implementation
    mandatory, otherwise OK

    <Clarke> new ABR proposal:


    Adaptive Streaming - revised proposal ...

    Aaron: Source ID added ...
    ... allows two separate streams
    ... enables swithcing lang, different decoders, ...
    ... Source ID main API change
    ... overlapping regions, rules, ... clarifications
    ... for compatibility reasons ... to nail down details
    ... Byte stream format ?

    Aaron: WebM and ISO file formats ... examples of usage
    ... How to limit the ...

    How much data buffered by browser

    waht tpyes of splices

    sample rate changes

    Appending byte ranges ...

    Clarke: Comments to authors ?

    Joe: Issues identified ?

    In section 8

    <kaz> [12]Open Issues


    Clarke: Administrative issue ... next week not chaired by

    Joe: Progress in the new TF ? If no, then can skip next week

    Clarke: Proceeding well, rules under creation, to become memebr
    of HTML WG to contirbute

    <kaz> [13]HTML WG discussion

      [13] http://lists.w3.org/Archives/Public/public-html/2012Mar/0450.html

    MarkW: Call for Consensus coming
    ... timing open

    Kaz: join HTML WG to participate ... name Encrypted Media TF
    ... not much an issue as TF only to create

    Clarke: Content protection is the first priority ... reqs to be
    ready ... next telco after two weeks ?


    Kilroy: Flow diagram sect. 1 in , CDM diagram in Protection
    proposal ...how to look as one

    <kaz> [14]Section 1 of "Encrypted Media Extensions" proposal


    [ adjourned ]

Summary of Action Items

    [NEW] ACTION: Clarke to work with Bob and modify the text om
    content protection requirement under consideration #9 based on
    today's discussion [recorded in

    [End of minutes]

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Received on Thursday, 15 March 2012 16:16:11 UTC

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