MSE questions from Open IPTV Forum, HbbTV and the UK DTG

I have received the following questions from a joint meeting between the Open IPTV Forum, HbbTV and the UK DTG.    These organizations originally sent a liaison statement to the W3C Web & TV IG:

https://lists.w3.org/Archives/Member/member-web-and-tv/2013Jan/0000.html (W3C member only link)

and as a follow up to that liaison I have arranged for some of the members of these external organizations to join our Tue Mar 19 Media TF meeting.



My plan is to add these questions to the Media TF meeting agenda for Tue Mar 19.  In addition we may have some new Bugzilla bugs filed against the MSE spec by these external experts.  If such bugs are created then I will also add those to the TF meeting agenda.



Please feel free to start a discussion on these questions in response to this email.


Q1. Are there plans for test cases for MSE?



Q2. Do you believe MSE contains the features needed for a DASH player that fully supports the DASH profiles defined by MPEG and by DASH-IF? If a DASH player on top of MSE could only support a subset of these profiles, is there any information on what could not be supported?



Q3. Has any thought gone into how MSE could be used with a media element whose playback rate was other than 0 or 1? Particularly rates greater than 1 or less than 0.



Q4. In section 8, it says;



>The combination of an initialization segment and any contiguous sequence of media segments associated with it must:

..

>If a track is encrypted, provide any encryption parameters necessary to

>decrypt the content (except the encryption key itself)



Is there a complete description for the handling of encrypted content with an embedded DRM?



Q5. The broadcasters in our 3 organisations have a requirement to know when a particular advert starts being played and stops being played so that they can report this information back to an advertising server. It seems to us that the (only?) way to achieve this with with MSE is to remember a) where in the timeline the advert has been inserted (as defined by timestampOffset) and b) the length of the advert. As the content is played, the app would poll the currentTime property of the media element and test if this was within an advert. Is this how you would expect this requirement to be met with MSE?


/paulc
HTML WG co-chair

Paul Cotton, Microsoft Canada
17 Eleanor Drive, Ottawa, Ontario K2E 6A3
Tel: (425) 705-9596 Fax: (425) 936-7329