Media Pipeline Task Force Teleconference

17 May 2012


See also: IRC log


Kazuyuki, Clarke, Glenn, Duncan, Joe, Narm, John, Niklas, ??P41, +1.908.541.aaee, Kevin, Aaron, Mark_Watson
Clarke Stevens


<kaz> agenda: http://www.w3.org/2011/webtv/wiki/MPTF/Agenda_Telco_17th_May_2012

Agenda Reivew by Chair

nothing to record

video in RTC context

Clarke: RTC uses some formats for Video and need to confirm what kind of video we use. Broadcase or Stored?
... should the tags for the Video in RTC be same as what we have here?

Joe: are there any online resources about RTC

<scribe> ACTION: Clarke send details of RTC WG [recorded in http://www.w3.org/2012/05/17-webtv-minutes.html#action01]

<trackbot> noticed an ACTION. Trying to create it.

<trackbot> Created ACTION-98 - Send details of RTC WG [on Clarke Stevens - due 2012-05-24].

Clarke: Clarke is travelling, so no meeting next week.

WebPerf group from Mark Watson

<kaz> [ fyi, LCWD announcement for 2 specs of the group: https://lists.w3.org/Archives/Member/chairs/2012AprJun/0052.html ]

<kaz> [ also Navigation Timing CR: http://www.w3.org/TR/2011/CR-navigation-timing-20110602/ ]

MarkW: For each HTTP request, is the performance information is provided? Mark checked this with the WebPerf WG
... the intent was to estimate the bandwidth via JavaScript.
... they have an API at the top level window object to get the performance information at the HTTP level.
... all this can be done via JavaScript

Duncan: Will this work only through JavaScript and no other method need to be used?

MarkW: Yes. the JavaScript module will directly get the information from HTTP layer.

MarkW: they dont increase the byte range.

Clarke: You have mentioned that they use a buffer. Does this create a problem?

MarkW: The buffer is only added when the HTTP request complete. The estimation can be done in short requests.

Bug Review

Clarke: No change since last week. Any new bugs to report?

Use cases in Content Protection

<Clarke> CP Spec: http://dvcs.w3.org/hg/webtv/raw-file/tip/mpreq/MPTF-CP-Requirements.html

<kaz> especially the Use Cases section

Clarke: Reviewing the Use case: Support Authorized Access to Content

Joe: this is high level and requirements of the use case are not discussed

Clarke: this is use case and may need more detail. Open to changes.

John: Authorized Access: focus is on Content Protection, but authorized access is a separate function. Is there a requirement for supporting authorization itself?

Clarke: No, a separate requirement is not captured

John: We should have either separate requirement or expand this.

Bob: Authorization is a saperate requirement
... web cryptography is looking into doing tools for these and we should co-ordinate.

John: In addition Authorization we should look into Device Authentication
... this is a requirement for TV devices
... should be able to initiate from a web app.
... even if Authorization and Authentication are not W3C specs, we should have a way to do it from web app.

Joe: prefer anonymous for authentication. Current spec does not cover Authentication. User Identification is not covered by current spec. Not sure if appropriate to put in this use case!

Clarke: Users already have to authenticate. We need to think if we should formalize this or not ...

Joe: Upto CDM, not sure if we can standardize

Aaron: Authentication may be controversial, because it may make tracking users easier.

<joesteele> +1

<joesteele> need to be careful about privacy

Bob: The DNT we have to make sure we are doing right.

MarkW: with webcrypto the identity you see via JavaScript is different from real identity.

Clarke: Summary: This will have to be broken up into multiple concepts and will work on it.

Use Case 2: Support for Commonly-used Container Formats

Clarke: Reviewing the Use Case 2

Joe: Will there be multiple of these, each for commonly used container formats?

Clarke: container format is to be defined.

John: your requirement is written as design guideline and may need rephrasing as a requirement that does not have content protection markup.

Clarke: The requirement says that content protection does not favor any specific container format

Use Case 3: Support for a Baseline CDM

Clarke: Reviewing the use case.

Use Case 4: Support for Browser-independent Implementation

Clarke: Reviewing the use case

<kaz> scribenick: kaz

Joe: difference between U3 and U4?

Clarke: you can support U4 without supporting U3
... opinions to express?

Joe: ability to get access the content
... unclear about the player actually play the content

Use Case 5: Support for Playback of Encrypted Adaptive Bit-rate Content

Clarke: comments?
... out of time
... no call next week

tx for taking notes, narm_gadiraju!

<Clarke> Thanks, Narm

[ adjourned ]

Summary of Action Items

[NEW] ACTION: Clarke send details of RTC WG [recorded in http://www.w3.org/2012/05/17-webtv-minutes.html#action01]
[End of minutes]

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$Date: 2012/05/18 07:39:58 $