Reporting schema for CMCD v2

[nicolaslevy]

As discussed at the DASH-IF meeting in Berlin, a new reporting schema is proposed for publication so that the MPD contains the necessary information for a client to configure the three CMCD v2 modes (Request, Response, and Event mode).

From the feedback received, this new schema should consider:

• Define X amount CMCD v2 targets
• For all modes, filter keys to send
• For Request mode, filter by cdn (location)
• Work with CDNs that support v1
• For Event mode, filter events
• Support for Annex I for Response and Event mode (i.e. to send authentication tokens)
• Override capabilities of upper level definitions (version, content id and session id)
• If session id is not defined the client should create a random uuid4
• Configuration for batching intervals in Response and Event mode, for both, time and size.
• A way to do sub-sampling (a probability number or something similar for the client to decide if send or not data). For this we added a "sample" option sample=N, where N is an integer between 0 and 100 inclusive and represents the percentage probability that that target should be used for the playback session (sid). The default is 100 if this parameter is omitted. So sample=20 would mean that 20% of sessions would use that target. It could be implemented by the player if Math.random()*100 <= N.

Below is an example of what this element could look like, this is an early draft that almost capture all those items:

<ClientDataReporting
  schemeIdUri="urn:dashif:cta-5004:2025">
  <CMCDParameters 
    version=2
    contentID="content-id-1"
    sessionID="session-id-1" > 
    <!--TODO: Support Annex I for sid if not defined random uuid4()-->
    <ReportingTargets>
      <RequestTarget 
        version=1
        serviceLocations="cdn-a"
        mode="query"
        keys="br sid cid"
        requestFilter="mpd segment steering" />
      <RequestTarget
        serviceLocations="cdn-b"
        mode="query"
        keys="br sid cid"
        requestFilter="mpd segment" />
      <ResponseTarget 
        mode="json"
        jsonBatchLimit="30 4"
        contentID="content-id-override"
        sessionID="session-id-override"
        keys="sid ot rc msd cid"
        url="http://content-steering.com/collector"
        requestFilter="mpd segment" />
      <EventTarget 
        url="http://user-analytics.com/cmcd-data-collector"
        timeInterval=10
        mode="header"
        keys="sid e mds sta cid"
        events="ps e t" />
      <EventTarget 
        url="http://thirdparty.com/v2endpoint"
        timeInterval=60
        mode="json"
        sample=20
        jsonBatchLimit="30 4" 
        keys="sid bl cid"
        events="t" >
        <!--TODO: 
           - cmcd spec add considerations for large batching intervals 
           - batchLimit 2 params: size and time
           - Update Annex I to new Dash 6th ed. 
         -->
            <EssentialProperty schemeIdUri="urn:mpeg:dash:urlparam:2014">
              <up:UrlQueryInfo xmlns:up="urn:mpeg:dash:schema:urlparam:2014"
                queryTemplate="token=$query:tokencmcd$"
                useMPDUrlQuery="true">
              </up:UrlQueryInfo>
            </EssentialProperty>
        </EventTarget>
    </ReportingTargets>
  </CMCDParameters>
</ClientDataReporting>