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15:50:22 <RRSAgent> logging to http://www.w3.org/2012/12/18-html-media-irc
15:50:24 <trackbot> RRSAgent, make logs public
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15:50:26 <trackbot> Zakim, this will be 63342
15:50:26 <Zakim> ok, trackbot; I see HTML_WG()11:00AM scheduled to start in 10 minutes
15:50:27 <trackbot> Meeting: HTML Media Task Force Teleconference
15:50:27 <trackbot> Date: 18 December 2012
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15:58:33 <adrianba> Chair: Paul Cotton
15:58:40 <adrianba> Agenda: http://lists.w3.org/Archives/Public/public-html-media/2012Dec/0027.html
15:59:02 <Zakim> HTML_WG()11:00AM has now started
15:59:09 <Zakim> +ddorwin
15:59:52 <pal> pal has joined #html-media
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16:01:16 <Zakim> +pal
16:02:00 <Zakim> +[Microsoft]
16:02:01 <acolwell> acolwell has joined #html-media
16:02:16 <Zakim> +Aaron_Colwell
16:02:36 <Zakim> +markw
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16:03:09 <Zakim> +[Microsoft.a]
16:03:11 <adrianba> zakim, [Microsoft.a] has adrianba, paulc
16:03:11 <Zakim> +adrianba, paulc; got it
16:03:20 <adrianba> zakim, who is on the phone?
16:03:20 <Zakim> On the phone I see ddorwin, pal, [Microsoft], Aaron_Colwell, markw, [Microsoft.a]
16:03:23 <Zakim> [Microsoft.a] has adrianba, paulc
16:03:42 <paulc> paulc has joined #html-media
16:03:55 <adrianba> ScribeNick: adrianba
16:04:01 <adrianba> Scribe: Adrian Bateman
16:04:18 <adrianba> zakim, [Microsoft] is johnsim
16:04:18 <Zakim> +johnsim; got it
16:04:25 <adrianba> zakim, who is on the phone?
16:04:25 <Zakim> On the phone I see ddorwin, pal, johnsim, Aaron_Colwell, markw, [Microsoft.a]
16:04:28 <Zakim> [Microsoft.a] has adrianba, paulc
16:04:50 <Zakim> +??P18
16:05:07 <BobLund> zakim, ??p18 is me
16:05:07 <Zakim> +BobLund; got it
16:05:32 <adrianba> TOPIC: Roll call, introductions and selection of scribe
16:05:57 <adrianba> paulc: done
16:06:06 <adrianba> TOPIC: Previous meeting minutes
16:06:11 <adrianba> http://www.w3.org/2012/12/04-html-wg-minutes.html
16:06:15 <adrianba> paulc: noted
16:06:21 <adrianba> TOPIC: Review of action items
16:06:28 <adrianba> paulc: none apply to MSE currently
16:06:39 <adrianba> TOPIC: Baseline documents and Bugzilla information
16:06:55 <adrianba> http://dvcs.w3.org/hg/html-media/raw-file/tip/media-source/media-source.html
16:07:14 <adrianba> paulc: prepared agenda last week - there have been a couple of editorial changes since then
16:07:28 <adrianba> .. changes made to align with pubrules
16:07:47 <adrianba> Media Source Extension bugs -> http://tinyurl.com/6pdnzej
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16:08:22 <adrianba> TOPIC: Progression to First Public Working Draft
16:08:44 <adrianba> paulc: here i pointed to bug 20253 which aaron created to indicate the results of our dec 4 discussion
16:09:03 <adrianba> ... where we said there were 7 bugs that were desirable to fix prior to FPWD
16:09:35 <adrianba> ... if you look at 20253 it indicates that the following have been processed: 17002, 17094, 18960, 18963, and 19531
16:09:44 <Zakim> + +1.613.287.aaaa
16:10:03 <MartinSoukup> zakim, aaaa is me
16:10:03 <Zakim> +MartinSoukup; got it
16:10:05 <adrianba> ... leaving outstanding 17006, 18962
16:10:22 <adrianba> ... 17006 is track language and kind
16:10:29 <adrianba> ... 18962 is allow appending with XHR
16:10:44 <adrianba> adrianba: those are assigned to me
16:11:05 <adrianba> paulc: can you give us a status update?
16:11:32 <adrianba> https://www.w3.org/Bugs/Public/show_bug.cgi?id=20434
16:13:58 <adrianba> adrianba: i filed this new bug which i think is blocking 18962
16:14:10 <adrianba> ... this deals with making append() async even for ArrayBuffer
16:14:14 <adrianba> ... details in the bug
16:14:51 <adrianba> acolwell: i have a concern about changing this late - have to think about this
16:14:59 <adrianba> ... seems like an IE implementation requirement
16:15:05 <adrianba> ... we've implemented this without
16:15:20 <adrianba> ... i do like the idea that it makes it consistent between the stream and non-stream version
16:15:42 <MartinSoukup> i believe if the API is going to change, it is better to make the change prior to FPWD
16:16:30 <adrianba> adrianba: of course we could make this sync by blocking but we'd prefer not to do that
16:16:37 <adrianba> acolwell: i need to think about this offline
16:17:01 <adrianba> paulc: let's pop-up to the fact that adrian made the XHR bug dependent on this
16:17:16 <adrianba> ... and we need to decide how to process the move to FPWD
16:17:35 <adrianba> ... practical situation is that my plan was to do a CfC in this group (might be as simple as doing it on the phone call)
16:17:49 <adrianba> ... but obviously we need to take a FPWD ready spec to the WG and do a CfC inside the WG
16:17:57 <adrianba> ... that call would normally last a week
16:18:08 <adrianba> ... the working group is not meeting this week or next week
16:18:14 <adrianba> ... possibly will meet on jan 3
16:18:30 <adrianba> ... i proposed that we not meet on dec 20 and dec 27
16:18:40 <adrianba> ... even if we went forward today, the CfC might have to be for 3 weeks
16:18:51 <adrianba> ... i'm reluctant to use one week when it would overlap with the holidays
16:19:19 <adrianba> ... i think we've lost our window of opportunity - i wonder if we should give the editors until early january to make progress and the do CfC in early january
16:19:28 <adrianba> acolwell: what is the benefit of doing it in this group first?
16:19:49 <adrianba> paulc: in some ways i'm being trained by the time i've spent monitoring the a11y task force
16:20:07 <adrianba> ... the a11y tf leadership have always been careful to ensure that they have consensus inside that group
16:20:18 <adrianba> ... it would be foolish to take to the WG and then have someone in the TF object
16:20:29 <adrianba> ... so what maciej was saying is what really matters is what the WG says
16:20:36 <adrianba> ... so we could do this informally in the TF
16:20:47 <adrianba> ... one possibility would be to look at TF schedule
16:21:19 <adrianba> ... we could agree that on jan 8 the editors will give us a draft FPWD with as many bugs closed as possible and on that call, which would normally be a EME call, we would test consensus to go to the WG
16:21:29 <adrianba> ... and then we'd go to the WG at that time
16:21:54 <adrianba> ... i think that is a strawman that avoids the perception we're trying to we're trying to sneak it in
16:22:03 <adrianba> ... how does that sound?
16:22:21 <adrianba> acolwell: i'm fine with that plan - can we fix more bugs in this time?
16:22:32 <adrianba> paulc: yes, editors can always add more
16:22:47 <adrianba> acolwell: i don't want to let more bugs block us getting to FPWD
16:23:04 <adrianba> paulc: understood
16:23:39 <adrianba> TOPIC: [MSE] Homework re: issues in the context of upcoming FPWD
16:23:39 <johnsim> +1
16:24:04 <adrianba> pal: i'm not opposed to proceed with regular draft publications so we don't fall into the trap of always trying to fix a bug and not publishing
16:24:16 <adrianba> ... so my proposal is to simply add a note in the WD pointing to that bug or issue
16:24:28 <adrianba> ... helping the reader identify areas still under discussion
16:24:48 <adrianba> ... also trying to encourage readers to provide feedback on those issues
16:25:36 <adrianba> paulc: these are bugs 19673, 20327, 19784, 19676
16:26:03 <adrianba> ... there are places identified in the spec to point to these bugs
16:26:14 <adrianba> pal: not just limited to these bugs - could be other bugs too
16:26:30 <adrianba> paulc: looking for the minimum necessary to declare victory - want to make you happy
16:26:59 <adrianba> ... in addition to this i'd like to suggest that the editors add a para to the status section that identifies the bugzilla component for this draft and a link to the search for outstanding bugs
16:27:14 <adrianba> ... there are examples in other previously published working drafts
16:27:23 <adrianba> ... that will highlight up front that there are outstanding bugs
16:27:42 <adrianba> ... that along with what pal has suggested for his bugs inlined into the document will make it very clear
16:27:58 <adrianba> ... it's like adding a health warning to particular spec sections
16:28:07 <adrianba> acolwell: i'll have to go look to add an example
16:28:20 <adrianba> adrianba: it's easy to add more to the status section - i can help
16:29:07 <adrianba> paulc: the current html wd includes a paragraph on this
16:29:38 <adrianba> [reads from html editor's draft]
16:29:53 <adrianba> paulc: editors should look at how this has been done in the past in this WG
16:30:51 <adrianba> q?
16:30:55 <acolwell> q+
16:31:10 <paulc> ack ac
16:31:37 <adrianba> acolwell: i have a concern that a couple of the bugs in the WD as a note elevates them to indicate that they will be addressed and in my mind not all have a convincing case
16:32:06 <adrianba> ... i don't think we've discussed enough and i think it would be misleading to indicate that these are going to change
16:32:14 <adrianba> ... not sure what the right balance is
16:32:16 <adrianba> q+
16:32:53 <pal> q+
16:32:54 <adrianba> paulc: the text from pal doesn't say whether it merits inclusion or not - just points to the bug
16:33:10 <adrianba> acolwell: but it's still up for discussion - would rather resolve than add text not resolved
16:33:38 <adrianba> paulc: the HTML5 WD had a way for people to mark bugzilla bugs and the editorial process put those bugs into the spec as a marker
16:33:46 <adrianba> ... WG in the past has had a low bar for doing that
16:33:51 <adrianba> acolwell: ok
16:34:19 <adrianba> paulc: if the text from pal indicated that this must change that would be different - but it's just noting the existence of the bug
16:34:21 <pal> q-
16:34:31 <adrianba> ... this is a common W3C procedure
16:35:09 <adrianba> paulc: if someone tried to argue that because we mentioned them we have to fix them in a particular way i wouldn't accept that
16:35:11 <adrianba> q?
16:35:20 <paulc> ack adrian
16:36:47 <adrianba> adrianba: i just wanted to emphasise that this has happened before
16:37:00 <adrianba> ... perhaps we could use ISSUE to explain why only a few bugs are in this state
16:37:18 <adrianba> paulc: i'd rather try to have some technical issues on this call and leave this to the editors
16:37:24 <adrianba> ... anyone have anything else to say on this?
16:37:50 <adrianba> paulc: overall plan is to get to CfC by jan 8
16:38:06 <adrianba> paulc: acolwell are there specific bugs you'd like to discuss?
16:38:52 <adrianba> TOPIC: Discussion of outstanding bugs
16:39:26 <adrianba> https://www.w3.org/Bugs/Public/show_bug.cgi?id=19784
16:39:39 <adrianba> timestampOffset with multiplexed Media Segments
16:40:02 <adrianba> pal: timestampOffset allows the start of a media segment to be offset by a value
16:40:21 <adrianba> ... the issue is that media segments that contain multiplex - the audio may start a little earlier
16:40:34 <adrianba> ... this is often done in DASH, blueray
16:40:41 <adrianba> ... to support splicing of different streams
16:41:15 <adrianba> ... the issue is the timestampOffset says you shall start playback at the beginning but you always want to splice at the video boundary not the audio boundary
16:41:33 <adrianba> ... but if audio starts earlier then you end up using the audio boundary not the video
16:41:43 <adrianba> ... this is only a problem for multiplexed media
16:42:05 <adrianba> acolwell: the spec says to resolving the splice on a per stream basis
16:42:15 <adrianba> ... so the splice for each stream is resolved independently
16:42:26 <adrianba> pal: where exactly in the media segment does the splice happen
16:42:41 <adrianba> ... does it mean the audio will be offset from the video
16:43:23 <adrianba> pal: original content has audio and video synced but has audio start earlier to allow cross-fade splicing
16:43:58 <adrianba> acolwell: i was assuming the audio frame already in the buffer - the cross fade would happen at the splice time?
16:44:24 <adrianba> pal: https://docs.google.com/open?id=0Bz7s0dhnv-7HYjhadTktTGhrd2M
16:44:31 <markw> q+
16:45:36 <adrianba> pal: [describes illustration]
16:46:13 <adrianba> acolwell: the timestamp offset is the value that is added to the timestamp in the media, not a reference to the start
16:46:22 <adrianba> ... it just adds to timestamp values
16:46:37 <adrianba> pal: i don't think mp4 allows negative offsets
16:48:00 <adrianba> acolwell: the current spec says for video the splice happens where you want it
16:48:12 <adrianba> ... say frame 1 starts at 33ms you replace frame 4 and move on
16:48:37 <adrianba> ... for audio the cross-fade would happen between frame 4 of original content and frame 1 of new content
16:48:48 <adrianba> ... and so wherever they overlap a cross-fade would happen
16:48:58 <adrianba> ... if you don't implement cross-fade then frame 4 would be dropped
16:49:05 <adrianba> ... and if there was a gap silence would be inserted
16:49:59 <adrianba> pal: i think the key is that even though it is audio/video multiplex, the splicing is resolve per stream type
16:50:03 <adrianba> ... that is key
16:51:03 <adrianba> ... second, i understand how if the video frame is some offset into the segment you can reduce the timestamp offset by a similar amount to make sure you have alignment
16:51:16 <adrianba> ... how do you tell it to start on the video frame?
16:51:34 <adrianba> acolwell: by the nature of how the html element the first video frame will be displayed before playback starts
16:51:34 <Zakim> -MartinSoukup
16:51:46 <adrianba> ...when it loads it automatically displays first frame
16:51:59 <adrianba> pal: by construction there is always a sync on the video frame
16:52:13 <adrianba> acolwell: the first frame is always displayed when the element is ready for playback
16:52:28 <adrianba> pal: when you hit play you wouldn't want audio to start with the overhang
16:52:41 <adrianba> acolwell: i think that's an implementation detail probably inconsistent with browsers today
16:52:52 <adrianba> ... think that's a HTML issue not media source
16:52:58 <adrianba> ... and it's a tiny time
16:53:02 <adrianba> pal: yes, you can notice 23ms
16:53:14 <adrianba> ... sounds like all that's needed is informative guidance to implementors
16:53:31 <adrianba> ... that timestampOffset will work as is but might need examples perhaps with diagram of how to use it?
16:53:51 <adrianba> paulc: please can you attach the pdf to the bug
16:54:10 <adrianba> pal: yes
16:54:47 <adrianba> paulc: do i take it that we have some level of consensus to deal with this bug 19784 that we don't believe we have a technical problem in the spec but the difficulty could be resolved with further explanatory material?
16:55:04 <markw> q-
16:55:27 <adrianba> acolwell: it sounds like an example that shows how this scenario would be resolved is required and then a note on implementors that at the beginning of playback possibly trimming the initial part of audio
16:55:44 <adrianba> paulc: perhaps the right tactic might be to get this possible resolution into the bugzilla bug
16:55:56 <adrianba> ... so that if it is not in FPWD then people would see that proposed disposition
16:55:57 <Zakim> -BobLund
16:56:09 <adrianba> ... leave it to acolwell and pal about how to get this into bugzilla
16:56:26 <adrianba> paulc: does the explanation for 19784 cascade to other bugs?
16:56:28 <adrianba> pal: no
16:56:34 <adrianba> paulc: so it was independent then
16:56:42 <adrianba> pal: yes i picked this one because it was independent
16:56:51 <adrianba> paulc: good, then we made progress
16:57:01 <adrianba> TOPIC: Other Business
16:57:15 <adrianba> paulc: not going to cover anything else
16:57:21 <adrianba> TOPIC: Chair and Scribe for next meeting
16:57:32 <adrianba> paulc: neither groups will meet dec 25 or jan 7
16:57:39 <adrianba> ... jan 8 would normally be EME group
16:57:47 <adrianba> ... but you should expect to see a combined agenda
16:58:01 <adrianba> ... so i can give update on MSE candidate FPWD document
16:58:08 <adrianba> ... so that i can take this to the working group
16:58:26 <adrianba> acolwell: is there a day we should get this published?
16:58:32 <pal> q+
16:58:35 <adrianba> paulc: would the previous week some time be okay?
16:58:41 <adrianba> ... by jan 4?
16:58:48 <adrianba> acolwell: i think that's fine
16:58:59 <adrianba> paulc: editors will deliver on or before jan 4
16:59:09 <adrianba> ... if it doesn't happen we'll adapt
16:59:27 <adrianba> ... want a stable document, consider a different URL for that doc
16:59:48 <adrianba> ... don't want the item out for CfC to change under the decision
17:00:20 <adrianba> TOPIC: Adjournment
17:00:34 <adrianba> paulc: wish everyone happy holidays - if you're travelling, travel safe
17:00:41 <adrianba> ... we'll talk again jan 8
17:00:42 <Zakim> -markw
17:00:44 <Zakim> -[Microsoft.a]
17:00:46 <Zakim> -Aaron_Colwell
17:00:46 <Zakim> -pal
17:00:46 <Zakim> -ddorwin
17:00:47 <Zakim> -johnsim
17:00:48 <Zakim> HTML_WG()11:00AM has ended
17:00:48 <Zakim> Attendees were ddorwin, pal, Aaron_Colwell, markw, adrianba, paulc, johnsim, BobLund, +1.613.287.aaaa, MartinSoukup
17:00:51 <adrianba> rrsagent, make minutes
17:00:51 <RRSAgent> I have made the request to generate http://www.w3.org/2012/12/18-html-media-minutes.html adrianba
17:00:55 <adrianba> rrsagent, make logs public
17:00:58 <adrianba> zakim, bye
17:00:58 <Zakim> Zakim has left #html-media
17:01:08 <adrianba> rrsagent, make minutes
17:01:08 <RRSAgent> I have made the request to generate http://www.w3.org/2012/12/18-html-media-minutes.html adrianba
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