15:01:49 RRSAgent has joined #html-media
15:01:49 logging to http://www.w3.org/2013/07/09-html-media-irc
15:01:51 RRSAgent, make logs public
15:01:51 Zakim has joined #html-media
15:01:53 Zakim, this will be 63342
15:01:53 ok, trackbot; I see HTML_WG()11:00AM scheduled to start now
15:01:54 Meeting: HTML Media Task Force Teleconference
15:01:54 Date: 09 July 2013
15:02:00 pladd has joined #html-media
15:02:07 Zakim, who is on the phone?
15:02:07 HTML_WG()11:00AM has not yet started, pladd
15:02:08 On IRC I see pladd, Zakim, RRSAgent, davide, glenn, Michael_Thornburgh, trackbot, wseltzer
15:02:12 MartinSoukup has joined #html-media
15:02:22 BobLund has joined #html-media
15:02:52 zakim, who's on the phone?
15:02:52 HTML_WG()11:00AM has not yet started, glenn
15:02:54 On IRC I see BobLund, MartinSoukup, pladd, Zakim, RRSAgent, davide, glenn, Michael_Thornburgh, trackbot, wseltzer
15:03:05 zakim, this will be html
15:03:05 ok, glenn, I see HTML_WG()11:00AM already started
15:03:12 adrianba has joined #html-media
15:03:13 zakim, who's on the phone?
15:03:14 On the phone I see +1.831.457.aaaa, pladd, ??P21, [Microsoft]
15:03:18 paulc has joined #html-media
15:03:20 +davide
15:03:21 zakim, ??p21 is me
15:03:21 +glenn; got it
15:03:24 zakim, i am aaaa
15:03:24 +Michael_Thornburgh; got it
15:03:24 Good morning
15:03:57 Agenda: http://lists.w3.org/Archives/Public/public-html-media/2013Jul/0008.html
15:04:13 I will need a scribe today.
15:04:48 acolwell has joined #html-media
15:04:49 zakim, who is on the phone?
15:04:49 On the phone I see Michael_Thornburgh, pladd, glenn, [Microsoft], davide
15:04:57 +Mark_Watson
15:05:04 markw has joined #html-media
15:05:33 jdsmith has joined #html-media
15:05:33 +[Microsoft.a]
15:05:35 pal has joined #html-media
15:05:44 Zakim, who is on the phone ?
15:05:44 On the phone I see Michael_Thornburgh, pladd, glenn, [Microsoft], davide, Mark_Watson, [Microsoft.a]
15:05:51 Zakim, Mark_Watson is markw
15:05:51 +markw; got it
15:05:58 zakim, who is on the call?
15:05:58 On the phone I see Michael_Thornburgh, pladd, glenn, [Microsoft], davide, markw, [Microsoft.a]
15:06:08 +Aaron_Colwell
15:06:27 +[Microsoft.aa]
15:06:36 + +1.613.287.aabb
15:06:37 zakim, [Microsoft.aa] is me
15:06:37 +adrianba; got it
15:06:42 zakim, aabb is me
15:06:42 +MartinSoukup; got it
15:06:42 zakim, [Microsoft] has paulc
15:06:43 +paulc; got it
15:06:59 zakim, [Microsoft.a] has jdsmith
15:07:00 +jdsmith; got it
15:07:09 ScribeNick: markw
15:07:10 zakim, who is on the call?
15:07:10 On the phone I see Michael_Thornburgh, pladd, glenn, [Microsoft], davide, markw, [Microsoft.a], Aaron_Colwell, adrianba, MartinSoukup
15:07:13 [Microsoft] has paulc
15:07:13 [Microsoft.a] has jdsmith
15:07:14 + +1.310.210.aacc
15:07:17 Scribe: Mark Watson
15:07:23 rrsagent, generate minutes
15:07:23 I have made the request to generate http://www.w3.org/2013/07/09-html-media-minutes.html paulc
15:07:28 Agenda: http://lists.w3.org/Archives/Public/public-html-media/2013Jul/0008.html
15:07:36 zakim, aaac is me
15:07:36 sorry, pal, I do not recognize a party named 'aaac'
15:07:53 zakim, [aacc] is pal
15:07:53 sorry, paulc, I do not recognize a party named '[aacc]'
15:07:54 zakim, aaac is +1.310.210.aacc
15:07:55 sorry, pal, I do not recognize a party named 'aaac'
15:08:06 zakim, [.aacc] is pal
15:08:07 sorry, paulc, I do not recognize a party named '[.aacc]'
15:08:08 zakim, +1.310.210.aacc is me
15:08:08 +pal; got it
15:08:19 you're typing aaac instead of aacc
15:08:35 Chair: Paul Cotton
15:08:43 Usual pattern: "Topic: xxxxx"
15:09:10 Topic: Previous meeting minutes
15:09:39 paulc: Propose to note previous minutes
15:09:46 Topic: Review of action items and issues
15:10:01 paulc: Embedded in agenda
15:10:07 +BobLund
15:10:08 Topic: MSE status and bugs
15:10:27 Latest Ed draft: http://dvcs.w3.org/hg/html-media/raw-file/tip/media-source/media-source.html
15:11:10 MSE bugs: http://tinyurl.com/6pdnzej
15:11:42 Topic: Pre-Last Call bugs
15:11:47 Bug 22148 - Request that we reconsider adding jitter to video quality metrics
15:11:55 https://www.w3.org/Bugs/Public/show_bug.cgi?id=22148
15:12:08 paulc: This is open, assigned to Aaron
15:12:32 acolwell: This this is answered. I will try to get this implemented this week.
15:12:54 paulc: If this is the only open one, we could go to LC before implementing it
15:13:11 Bug 22137 - changes in number of audio tracks during advert insertion
15:13:21 https://www.w3.org/Bugs/Public/show_bug.cgi?id=22137
15:13:22 ACTION-21?
15:13:22 ACTION-21 -- Adrian Bateman to work with Jerry to review bug 22137 and provide feedback -- due 2013-07-02 -- PENDINGREVIEW
15:13:22 http://www.w3.org/html/wg/media/track/actions/21
15:13:49 See latest comment at https://www.w3.org/Bugs/Public/show_bug.cgi?id=22137#c5
15:13:59 jdsmith: We had some discussion and comments are in the bug. Some aspects tricky. Trade-off between throwing an error if track numbers are reduced vs trying to play.
15:14:08 ... Trying to play is a good goal
15:14:11 q+
15:14:19 ... Local language might be preferred for example
15:14:26 q+
15:14:31 ack ad
15:15:35 q+
15:15:36 adrianba: Aaron's compromise proposal was what the original bug was asking for. In summary the difference between what the current spec says (prohibit track changes) and coming up with heuristics for deciding on which track to continue with when available tracks change
15:15:42 ... not obvious we have a clear answer
15:16:40 ... in out media engine we look at languages, formats and pick default track. Other media engines might do something different. Getting interop might be hard.
15:16:54 ... Is this something we really need to solve now ?
15:17:04 q+
15:17:15 ... If yes, how precisely should heuristics be defined and does it need to be repeatable ?
15:17:55 Michael_Thornburgh: I'll add a note today to eb bug about the main usecase: separate video and audio tracks coming in separately and then switch to an add which is multiplexed
15:18:10 q+
15:18:11 ... so you are going from 0 to 1 track of a particular type or 1 to 0
15:18:16 ack mich
15:18:45 ack bob
15:19:12 BobLund: Issues adrianba raised are independent of MSE and apply to any media resource where the set of tracks changes. There's a resolved bug in the HTML5 spec on this.
15:19:21 What is the HTML5 bug number?
15:19:34 ... There is some ambiguity about how applications should respond, but it's not just an MSE issue
15:20:11 ... MSE issue is whether we want to allow those track changes at all - a separate issue from how you deal with them when the happen
15:20:26 ... Should just discuss whether we allow track changes in MSE
15:20:49 Is this a case where the spec should say the choice of text track is "implementation-defined"?
15:21:08 paulc: adrianba, is this a case where we should just say "implementation defined" ?
15:21:52 ... if we did this and got into Last Call it could be a source of objectiosn
15:21:59 ack paulc
15:22:01 s/objectiosn/objections/
15:22:09 ack acol
15:22:32 acolwell: First on Michael_Thornburgh's use case, those transitions would actually introduce new tracks
15:23:01 ... if one of the source buffers suddenly had an extra track, then that should introduce a new track in HTML5 and you ought to actually select that new track
15:23:24 q+
15:23:25 ... not clear that UA could automatically detect that it should switch just based on the absence of data in the old source buffer and the appearance of the new track
15:24:09 http://www.w3.org/TR/2012/CR-html5-20121217/embedded-content-0.html#audiotracklist, http://www.w3.org/TR/2012/CR-html5-20121217/embedded-content-0.html#texttracklist
15:24:11 q+
15:24:17 ... Second, on BobLund's comment, I think HTML has language about tracks coming and going which is fine but the concern is whether the media engines can actually support that and what bar do we want to set for minimal client implementations
15:24:27 ... seems to me it is more in the scope of MSE than HTML5
15:24:33 ack pal
15:24:34 q+
15:24:52 pal: There is already in HTML5 a means of selecting which track should be played, correct ?
15:24:57 acolwell: yes
15:25:17 pal: so for this use-case with an ad insertion the app can select which track will start playing
15:25:58 acollwell: when they append the new data they should get a notification of the new track on the HTMLMediaElement and the app could select then. But there is no implicit way for the track selection to happen automatically
15:26:09 pal: would seem dangerous to have a track selected automatically
15:26:25 ... another thing is whether we should impose constraints on track switching
15:26:34 pal has joined #html-media
15:26:34 ... perhaps requires multiple decoders etc.
15:26:54 acolwell: current text does not allow track count or codecs to change exactly for that reason
15:27:27 ... my comment was just to define minimal behaviour so that if the track counts do change the behaviour is deterministic, but don't require the UA to actually handle the new tracks
15:27:45 ack bob
15:28:17 BobLund: links above are to the HTML IDL that provide add/remove track capability
15:28:48 ... app can select the tracks - no ambiguity there - I agree with acolwell that the issue for MSE is whether or not to support these track changes
15:28:57 ... if we do support them the UA behaviour is clear in HTML
15:28:59 q+
15:30:07 http://www.w3.org/TR/2012/CR-html5-20121217/embedded-content-0.html#audiotracklist-and-videotracklist-objects
15:30:38 ack adrian
15:31:27 adrianba: in response to BobLund, HTML5 is clear what event should be fired in response to track add/remove.
15:31:59 ... what's missing is what to do if the track that you are playing disappears. Should you enable another track automatically ?
15:32:06 ... and how do you decide which one ?
15:32:35 ... alternatives are to give an error and stop playing or to continue playing
15:32:43 q+
15:33:20 ... ideally we would have the ability to schedule a track change at some time in the future
15:33:46 ... so for example when appending the new track you could let the media element know that you will want to change at some future point
15:34:01 q+
15:34:16 ... might not be able to do this right away, but seems like a long-term goal
15:34:46 ... propose converting this to an HTML5 bug
15:34:48 q+
15:34:49 +1 to moving this to an HTML5 bug
15:35:00 ... proposing future scheduling of track changes
15:35:01 ack aaron
15:35:02 q-
15:35:27 acolwell: agree with adrianba that providing information about how to switch tracks at a particular point in the timeline
15:35:56 ... immediate problem is whether to trigger an error (which is what is says now) or whether to change that to say it's allowed but may not be exposed by the UA
15:36:11 ... so then this new future spec can be used to control the changes
15:36:31 ack acol
15:36:50 q-
15:37:16 q+
15:37:19 Mark: A simple suggestion is to possibly mark one of the tracks as the default if one of the tracks goes away.
15:37:57 Mark: If the audio track goes away maybe the UA will stall and we don't want the UA arbirtarily picking tracks.
15:38:02 ack markw
15:38:22 markw: perhaps allow a track to be flagged from the MSE side as the default track to be used if the currently playing track ends
15:38:25 Aaron: There is currently no way for the applications to know the track ids.
15:38:45 acolwell: that could be tricky because There is currently no way for the applications to know the track ids
15:38:50 q+
15:39:02 ack Michael
15:39:45 Michael_Thornburgh: provding information for track switches at append time would unify the append time behaviour with the rendering behavior
15:39:57 ... woudl also solve the stall problem when there were suddenly zero tracks
15:40:03 s/woudl/would/
15:40:21 ack pal
15:40:27 ... I'll add this to my comment on the bug
15:40:43 q+
15:40:44 pal: acolwell, when you said the MSE had no concept of trackid, what did you mean
15:41:16 acolwell: track selection is abstracted away from track ids in the media itself. There is just a track list and you can select from that. You can't use track id on that side.
15:41:55 pal: There are attributes like kind, which you can use, but there's no id on the media element side, right ?
15:42:04 acolwell: yes, there's no id which is guaranteed to be the id from the container
15:42:12 pal: ?
15:42:34 acolwell: may be benefits of exposing the track ids, but that's not this particular issue
15:42:46 q?
15:42:53 pal: application should be able to select which track to play from what it has inserted and wants to play the French track or track id 5
15:43:07 We had MSE bugs for this issue
15:43:09 acolwell: you can't select by track id but you can select by language etc.
15:43:26 ... underlying container id is not exposed. it can change
15:43:29 ack adrian
15:44:09 adrianba: this topic is the subject of MSE bugs, we discussed a long time ago that mapping from track id to HTML track lists is tricky. Thought we had resolved that
15:44:21 ... should check in time as there's another issue
15:44:37 ... summary: propose to move this to be solved in HTML5 in a broader way
15:44:45 paulc: in 5.0, the CR ?
15:44:50 adrianba: no, 5.1
15:44:56 ... feature request
15:44:58 q+
15:45:10 ack acol
15:45:38 acolwell: would that HTML5 proposal remove the current resriction in MSE ?
15:45:40 Move to HTML5 -> create a new 5.1 bug that references this bug
15:45:58 adrianba: right, I'm proposing we make no change to MSE now and potentially change that in future
15:46:17 paulc: this means creating a new HTML5 bug referring to this one
15:46:36 paulc: is there consensus today to do that ?
15:46:53 paulc: not today
15:47:16 Bug 22136 - Inband Storage for SPS/PPS in ISO BMFF
15:47:22 https://www.w3.org/Bugs/Public/show_bug.cgi?id=22136
15:47:27 ACTION-22?
15:47:27 ACTION-22 -- Adrian Bateman to work with jerry to confirm the proposal in 22136 is acceptable -- due 2013-07-02 -- PENDINGREVIEW
15:47:27 http://www.w3.org/html/wg/media/track/actions/22
15:48:09 jdsmith: There's an MPEG DASH specification that requires inband SPS/PPS support
15:48:20 ... for ISO BMFF part 15. Currently in draft state
15:48:41 ... hard to require support when it is not yet stable
15:49:09 paulc: what is the exact status
15:49:11 ... ?
15:49:21 jdsmith: don't know exact status
15:49:28 paulc: we should find that out first
15:50:10 http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=62115
15:50:14 q+
15:50:24 DIS ballot, close of voting
15:50:49 ack adrian
15:51:22 adrianba: can we close ACTION-21 and ACTION-22 ?
15:51:35 ... if we identify status of ISO spec as unstable, then what ?
15:52:18 paulc: markw identified status as DIS, which is pretty stable
15:52:30 The status is at: http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=62115
15:52:37 Getting the actual document is a different matter
15:53:22 paulc: looks like it when into DIS in April
15:53:36 ... suggest adrianba looks at how stable this is
15:54:09 Note this is just from searching for 14496-15 amendment 2 which is HEVC support. I am not *certain* this contains the SPS/PPS thing
15:54:17 though that would make sense
15:54:31 ACTION-21: need to confirm exact status of the proposal for SPS/PPS
15:54:31 Notes added to ACTION-21 Work with Jerry to review bug 22137 and provide feedback.
15:55:03 s/ACTION-21/ACTION-22/
15:55:15 -BobLund
15:55:28 Bug 22117 - Add a conformance section
15:55:39 paulc: asked Cyril what he want to do about this item
15:55:48 ... waiting for response
15:55:56 Bug 22112 - Merge appendBuffer and appendStream text
15:56:09 https://www.w3.org/Bugs/Public/show_bug.cgi?id=22112
15:56:20 paulc: This is resolved, fixed
15:56:24 https://www.w3.org/Bugs/Public/show_bug.cgi?id=22112 is resolved fixed
15:56:57 paulc: those were the 5 bugs blocking LC. One is resolved. The first one Aaron will implement in the next two weeks
15:57:12