- From: Kazuyuki Ashimura <ashimura@w3.org>
- Date: Fri, 3 Apr 2015 02:01:50 +0900
- To: "public-tvapi@w3.org" <public-tvapi@w3.org>
- Message-ID: <CAJ8iq9VhF6HwfL2qjwwEcBmjar-SVdrG5N=_VN1tFJ_236jnLQ@mail.gmail.com>
Sorry for the delay.
The minutes from the TV Control API CG call on 17 March 2015
are available at:
http://www.w3.org/2015/03/17-tvapi-minutes.html
also as text below.
Thanks a lot for taking these minutes, Chris!
Kazuyuki
---
[1]W3C
[1] http://www.w3.org/
- DRAFT -
TV Control API CG
17 Mar 2015
[2]Agenda
[2] https://www.w3.org/community/tvapi/wiki/Main_Page/Agenda_Telco_Mar_17_2015
See also: [3]IRC log
[3] http://www.w3.org/2015/03/17-tvapi-irc
Attendees
Present
Bin, Kaz, Daniel, Chris, Paul, Alex
Regrets
Chair
Bin
Scribe
Chris
Contents
* [4]Topics
1. [5]Summary of TV Developer Meetup in Tokyo
2. [6]Review of action items
* [7]Summary of Action Items
__________________________________________________________
Summary of TV Developer Meetup in Tokyo
Daniel: We had a 2 day developer meetup, looking at the TV API
... from a Hybridcast and TV API point of view
... We looked at things in Hybridcast not supported by the TV
API
... Firstly, the triggered interactive overlay. Could this be
split into two requirements: a trigger requirement, and an
overlay requirement
... There could be two kinds of triggers, one with a
pre-defined time, and one that is generated live
... For those with pre-defined times, could the in-band
resource track spec be used?
<ddavis>
[8]http://www.w3.org/2014/05/28-webtv-minutes.html#item05
[8] http://www.w3.org/2014/05/28-webtv-minutes.html#item05
Bin: There can be relative time stamps encoded in the stream
for triggering events
... The service provider can signal events, say every 10
minutes
Paul: There is also an alarm clock API
Daniel: Can out of band triggers be supported by server sent
events?
<ddavis>
[9]https://www.w3.org/community/tvapi/wiki/Main_Page/Requiremen
ts_Mapping
[9] https://www.w3.org/community/tvapi/wiki/Main_Page/Requirements_Mapping
Daniel: Hybridcast does not have a channel change event, as the
application is closed on changing channel
Paul: Hybridcast and HbbTV are essentially channel-bound, so
changing channel discards the interactive environment, to be
replaced with a new one.
... With the Open IPTV Forum specs, the application persists,
this is described in the application lifecycle model in the DAE
Daniel: The group was wondering whether the TV control API
should converge these two approaches
Paul: The issue of a security model was raised on the mailing
list, and there are privacy concerns too.
Daniel: We discussed using watermark fingerprint triggers for
synchronising alternate streams.
Bin: With the supplemental triggers, these are optional, if
present they should be surfaced by the API
... We would have to define the content type and data
structures for these triggers, to identify these as trigger
metadata
... Some fields are mandatory, such those controlling the as
start time and end time/duration of the trigger
<ddavis> Type: video/x-iptvf-broadcast
Daniel: It would help to write down more of this detail in the
requirements
<ddavis> <param name="video"
value="arib://<original_network_id>.<transport_stream_id>.<serv
ice_id>[;<content_id>]
[.<event_id>]/<component_tag>[;<channel_id>]">
<ddavis>
[10]http://www.w3.org/TR/mediacapture-streams/#idl-def-MediaStr
eam
[10] http://www.w3.org/TR/mediacapture-streams/#idl-def-MediaStream
Daniel: Regarding integration with HTML5 audio and video
elements, Hybridcast a specific content-type, with parameters
not available in the media stream
Paul: There is also a different state machine, when comparing
HTML5 media with OIPF
... Looking at combining the W3C specs, we've found pausing
live TV in a media element would require reinitialising the
media element
... Chris suggested maybe allowing buffering with MediaStreams,
but do we define that or put this to that group
Daniel: Emergency notifications are implemented by a separate
system, EWS, not within Hybridcast
<aldafu> Zakim: aacc is me
Daniel: There is an earthquake prediction service, which may
need to be triggered differently
Paul: In the US there is a classification, different alerts
have different priorities
Daniel: Regarding the EPG, we have a getProgrammes method in
the mapping table, which takes an options object
... our API should allow more filtering options, such as by
type of content (movies, sport)
... also, get EPG by channel
... the duration option is confusing, as its the time range for
the search, maybe we should change this to endTime?
Paul: There are lots of ways to search, so with TV Anytime, we
have attribute pairings, more schema-less to allow more
flexible data models
Daniel: The general view was to allow more ways to search for
programmes
<ddavis>
[11]https://w3c.github.io/tvapi/spec/#h-tvprogram-interface
[11] https://w3c.github.io/tvapi/spec/#h-tvprogram-interface
Daniel: The TVProgram interface, should there be both a short
description and a long description, is it a satellite or
terrestrial programme.
... The getAudioLanguages and getSubtitleLanguages methods were
felt to be too restrictive. There can be alternate commentaries
but in the same language.
... An API like getAudioTracks might be more flexible, similar
for subtitles: getSubtitleTracks
... The satellite/terrestrial could be added to the
TVChannelType enum
... The isFree flag on the TVChannel could be added to the
TVProgramme object, for free channels that contain some paid
programmes
... Regarding parental control, this could be done at the
programme or at the system level, we may need to clarify our
requirements
... We'll share our notes from the meeting
Paul: Did the group identify anything missing?
Daniel: Maybe more device information, with properties such as
manufacturer, but we need to identify requirements.
Bin: Which group is working on the in band tracks?
<ddavis> [12]https://www.w3.org/community/inbandtracks/
[12] https://www.w3.org/community/inbandtracks/
<ddavis>
[13]http://dev.w3.org/html5/html-sourcing-inband-tracks/
[13] http://dev.w3.org/html5/html-sourcing-inband-tracks/
Paul: This is looking at mappings from ISDB, ATSC etc to tracks
associated with a video element
Bin: I have an interest in the encoding mechanism, for example,
a raw A/V stream from the studio, how do we add the triggers
and encode them within the stream. Which is the easiest way to
do this during encoding?
... The dataCue can provide an abstraction over the underlying
transport method
Paul: HbbTV defines stream events. There's a method
addStreamEventListener. How it's encoded in the transport
stream would be specified by DVB
Daniel: One other comment, more for the multi device timing
comnunity group: HTML5 needs a more accurate way to reference
the timeline, e.g., for ad insertion. for example, the
timeupdate event is only generated every 250ms
... That's all our feedback, we had a good useful discussion
today.
Review of action items
<Bin_Hu>
[14]http://www.w3.org/community/tvapi/track/actions/open
[14] http://www.w3.org/community/tvapi/track/actions/open
<ddavis> ACTION: ddavis to share wiki page containing feedback
from Japan TV dev meetup [recorded in
[15]http://www.w3.org/2015/03/17-tvapi-minutes.html#action01]
<trackbot> Created ACTION-28 - Share wiki page containing
feedback from japan tv dev meetup [on Daniel Davis - due
2015-03-24].
Alex: with action 23, the feedback and discussion about action
24 is related to this, in particular the background task for
recording
Bin: So we can close action 23
... Paul and Chris have reported their findings for actions 24
and 25, on recording and timeshifting
<kaz> action-23?
<trackbot> action-23 -- Alexander Futász to Email the mailing
list regarding the recording.series requirement and proposed
solutions -- due 2015-02-24 -- CLOSED
<trackbot>
[16]http://www.w3.org/community/tvapi/track/actions/23
[16] http://www.w3.org/community/tvapi/track/actions/23
<kaz> action-24?
<trackbot> action-24 -- Paul Higgs to Look at the media capture
and streams api and compare against our recording and
timeshifting requirements -- due 2015-04-14 -- OPEN
<trackbot>
[17]http://www.w3.org/community/tvapi/track/actions/24
[17] http://www.w3.org/community/tvapi/track/actions/24
<kaz> action-25?
<trackbot> action-25 -- Chris Needham to Look at the
timeshifting requirements and the html video element -- due
2015-03-17 -- OPEN
<trackbot>
[18]http://www.w3.org/community/tvapi/track/actions/25
[18] http://www.w3.org/community/tvapi/track/actions/25
Paul: We need to ensure our API meets regulatory requirements
regarding background workers, as TV devices go into standby
mode
... It would be useful to see some examples of how the various
APIs fit together
<Paul_Higgs> what I call the alarm clock API is
[19]http://www.w3.org/2012/sysapps/web-alarms/
[19] http://www.w3.org/2012/sysapps/web-alarms/
<Paul_Higgs> sorry, I have a hard stop now - I think this call
is just scheduled for 1 hour!
Bin: For action 25 (time shifting), we can do some more
investigation, look again at our requirements, also we should
understand the rationale for preventing buffering of
MediaStreams. We should do this before proposing any changes.
<scribe> ACTION: Chris to look further into timeshifting and
MediaStream API rationale [recorded in
[20]http://www.w3.org/2015/03/17-tvapi-minutes.html#action02]
<trackbot> Created ACTION-29 - Look further into timeshifting
and mediastream api rationale [on Chris Needham - due
2015-03-24].
Bin: we'll leave actions 26 and 27 open, and hopefully report
on these next time
<kaz> action-26?
<trackbot> action-26 -- Bin Hu to Contact sean and add
emergency alert requirements to the spec -- due 2015-02-24 --
OPEN
<trackbot>
[21]http://www.w3.org/community/tvapi/track/actions/26
[21] http://www.w3.org/community/tvapi/track/actions/26
<kaz> action-27?
<trackbot> action-27 -- Bin Hu to Work on triggered interactive
overlay requirements -- due 2015-02-24 -- OPEN
<trackbot>
[22]http://www.w3.org/community/tvapi/track/actions/27
[22] http://www.w3.org/community/tvapi/track/actions/27
<kaz> [ adjourned ]
Summary of Action Items
[NEW] ACTION: Chris to look further into timeshifting and
MediaStream API rationale [recorded in
[23]http://www.w3.org/2015/03/17-tvapi-minutes.html#action02]
[NEW] ACTION: ddavis to share wiki page containing feedback
from Japan TV dev meetup [recorded in
[24]http://www.w3.org/2015/03/17-tvapi-minutes.html#action01]
[End of minutes]
__________________________________________________________
Minutes formatted by David Booth's [25]scribe.perl version
1.140 ([26]CVS log)
$Date: 2015/04/02 16:01:22 $
[25] http://dev.w3.org/cvsweb/~checkout~/2002/scribe/scribedoc.htm
[26] http://dev.w3.org/cvsweb/2002/scribe/
--
Kaz Ashimura, W3C Staff Contact for Auto, TV, MMI, Voice, Geo and NFC
Tel: +81 3 3516 2504
Received on Thursday, 2 April 2015 17:03:00 UTC