14:45:19 RRSAgent has joined #html-media 14:45:19 logging to http://www.w3.org/2012/10/23-html-media-irc 14:45:21 RRSAgent, make logs public 14:45:21 Zakim has joined #html-media 14:45:23 Zakim, this will be 63342 14:45:23 ok, trackbot; I see HTML_WG()11:00AM scheduled to start in 15 minutes 14:45:24 Meeting: HTML Media Task Force Teleconference 14:45:24 Date: 23 October 2012 14:45:30 zakim, ping me in 15 minutes 14:45:30 ok, matt 14:56:21 pal has joined #html-media 14:56:35 paulc has joined #html-media 14:56:42 adrianba has joined #html-media 14:58:07 HTML_WG()11:00AM has now started 14:58:14 + +1.650.525.aaaa 14:58:22 zakim, i am aaaa 14:58:22 +pal; got it 14:58:40 Agenda: http://lists.w3.org/Archives/Public/public-html-media/2012Oct/0053.html 14:59:23 zakim, dial matt-voip 14:59:23 ok, matt; the call is being made 14:59:25 +Matt 14:59:29 strobe has joined #html-media 14:59:50 johnsim has joined #html-media 14:59:55 zakim, who is on the phone? 14:59:56 On the phone I see pal, Matt 15:00:08 +[Microsoft] 15:00:19 zakim, [Microsoft] has paulc,adrianba 15:00:19 + +1.415.867.aabb 15:00:21 +paulc, adrianba; got it 15:00:21 +[GVoice] 15:00:30 matt, you asked to be pinged at this time 15:00:59 zakim, mute me 15:00:59 Matt should now be muted 15:01:03 zakim, unmute me 15:01:03 Matt should no longer be muted 15:01:11 Zakim, +1.415.867 is me 15:01:11 +strobe; got it 15:01:17 zakim, mute me 15:01:17 Matt should now be muted 15:01:21 +[Microsoft.a] 15:01:31 ScribeNick: adrianba 15:01:36 Scribe: Adrian Bateman 15:01:39 Chair: Paul Cotton 15:01:50 Agenda: http://lists.w3.org/Archives/Public/public-html-media/2012Oct/0053.html 15:01:53 zakim, who is on the phone 15:01:53 I don't understand 'who is on the phone', johnsim 15:02:00 acolwell has joined #html-media 15:02:01 zakim, who is on the phone? 15:02:01 On the phone I see pal, Matt (muted), [Microsoft], strobe, [GVoice], [Microsoft.a] 15:02:03 [Microsoft] has paulc, adrianba 15:02:27 zakim, [Microsoft.a] is johnsim 15:02:27 +johnsim; got it 15:02:28 MartinSoukup has joined #html-media 15:02:40 (wait, I may be GVoice instead, let me reassociate) 15:02:55 +Aaron_Colwell 15:03:23 zakim, who is on the phone? 15:03:23 On the phone I see pal, Matt (muted), [Microsoft], strobe, [GVoice], johnsim, Aaron_Colwell 15:03:26 [Microsoft] has paulc, adrianba 15:03:36 Present+ markw 15:03:37 Clarke has joined #html-media 15:03:51 TOPIC: Roll call, introductions, selection of scribe 15:03:53 paulc: done 15:04:01 TOPIC: Previous meeting minutes 15:04:06 + +1.303.661.aacc 15:04:19 paulc: the most significant thing was that we agreed to triage bugs and Aaron indicated he would update the spec 15:04:19 zakim, aacc is me 15:04:19 +Clarke; got it 15:04:25 ... these are on the agenda 15:04:34 TOPIC: Review of action items 15:04:38 ACTION-6? 15:04:38 ACTION-6 -- Aaron Colwell to give a couple of examples for section 2 -- due 2012-09-04 -- OPEN 15:04:38 http://www.w3.org/html/wg/media/track/actions/6 15:04:52 paulc: this is still outstanding, correct? 15:05:00 + +1.613.491.aadd 15:05:05 ddorwin has joined #html-media 15:05:08 zakim, aadd is me 15:05:09 acolwell: we discussed this amongst the editors but not shared anything public 15:05:10 +MartinSoukup; got it 15:05:17 ACTION-6 due nov 1 15:05:17 ACTION-6 Give a couple of examples for section 2 due date now nov 1 15:05:28 + +1.425.202.aaee 15:05:33 TOPIC: Baseline documents and Bugzilla information 15:05:42 http://dvcs.w3.org/hg/html-media/raw-file/tip/media-source/media-source.html 15:05:43 zakim, aaee is me 15:05:43 +ddorwin; got it 15:05:53 paulc: Last updated Oct 18 15:05:58 http://lists.w3.org/Archives/Public/public-html-media/2012Oct/0039.html 15:06:16 paulc: aaron do you want to say anything about this? 15:06:44 acolwell: the changes might be surprising because i split up the algorithm a bit to make it easier to understand 15:07:00 zakim, who is noisy? 15:07:10 matt, listening for 10 seconds I heard sound from the following: [Microsoft] (7%), Aaron_Colwell (73%), MartinSoukup (49%), ddorwin (25%) 15:07:31 ... there isn't really a functional change - should just take a look at this change 15:07:49 ... added initial description of remove() 15:08:19 ... doing more to this is on the agenda for tpac 15:08:54 zakim, who is noisy? 15:09:02 zakim, who is noisy? 15:09:04 adrianba, listening for 10 seconds I heard sound from the following: [Microsoft] (37%), Aaron_Colwell (63%), MartinSoukup (54%), ddorwin (52%) 15:09:15 paulc, listening for 10 seconds I heard sound from the following: [Microsoft] (37%), johnsim (5%), Aaron_Colwell (5%), ddorwin (64%) 15:09:19 zakim, mute MartinSoukup 15:09:19 MartinSoukup should now be muted 15:09:51 acolwell: also updated media format section with more clarifications 15:10:34 TOPIC: TPAC F2F discussion plans 15:10:58 paulc: two weeks ago the editors proposed to triage the existing bugs 15:11:04 ... they've done this 15:11:27 ... the attachment to the mail from the editors indicates the current status of bugs broken down into clarifications or new features 15:11:42 ... and identifies the ones we want to discuss 15:12:46 paulc: the first observation we should make is that the editors have resolved some of the bugs 15:12:57 ... the majority of the new features are on the TPAC discussion list 15:13:06 ... i don't think we need to drill on the bugs resolved 15:13:13 ... one or more were resolved NEEDSINFO 15:13:20 ... let's deal with them at a high level 15:13:52 acolwell: 18922, request to have a better example that is codec and format agnostic 15:14:24 ... initially responded that the API expects you to know the format, resolved asking for a better example that you'd like to see since we don't think we can do this 15:14:32 ... but please give an example of what you'd like to see 15:14:53 joesteele has joined #html-media 15:15:13 acolwell: 18921, we think this is a misunderstanding of the goal of the API - this was requested adding arbitrary media data but the API requires you to know something about the data 15:15:43 acolwell: 18920, we discussed this on the call and the consensus was to keep the type parameter to allow UAs to fail fast 15:15:52 + +1.408.536.aaff 15:16:01 acolwell: 17000, we decided to defer this one because we don't have a great idea of what this should entail 15:16:12 acolwell: those are all the ones resolved 15:16:16 ddorwin has joined #html-media 15:16:44 paulc: my plan is that we won't revisit these at TPAC - if anyone has objections to the resolutions then they should reopen the bug with their problem statement 15:16:52 Zakim, aaff is joesteele 15:16:52 +joesteele; got it 15:16:56 ... next we should go on to the items for discussion at TPAC 15:17:11 acolwell: 18592, how much data to ensure uninterrupted playback 15:17:29 ... this is about how appending data to the sourcebuffer affects the HTML media element readystate 15:17:50 ... some discussion in the bug, there are trade-offs between different solutions, which we should discuss 15:18:01 MartinSoukup has joined #html-media 15:18:11 ... this might affect autoplay, for example, and we need to decide if and how to handle this 15:18:30 acolwell: 18575, this is related to ACTION-6 15:18:51 ... i sent something to the editors about this, which i can publish beforehand to help the discussion 15:19:05 ... some parts of section 2 are covered by algorithms and might be deleted 15:19:14 ... other parts might be moved to other areas 15:19:23 ... and some we need to figure out how to rewrite them 15:19:31 ... then we can discuss including at TPAC 15:19:55 ... the main thing is to understand the balance between normative and informative 15:20:03 paulc: let's get that out quickly 15:20:13 acolwell: that's fine - it's basically a copy and paste 15:20:24 acolwell: 18601, this is the topic from a couple of calls ago 15:20:31 ... main goal is to close this discussion 15:20:42 ... particularly about how to handle transport streams 15:20:57 acolwell: 18960, specifying how track IDs are generated 15:21:23 paulc: does the bug here point to the HTML5 bug? 15:21:55 acolwell: no, i'll find that - i think the bug is relevant to 17002 15:21:55 markw has joined #html-media 15:22:05 ... this got deferred to HTML.next 15:22:24 paulc: i wonder if we should ask for that bug to be discussed by HTML WG as a whole 15:22:27 MartinSoukup has joined #html-media 15:22:48 ... because we don't want the media topics discussed if we need that discussed by a broader group 15:23:00 acolwell: that's fine 15:23:05 https://www.w3.org/Bugs/Public/show_bug.cgi?id=18971 15:23:09 paulc: if we have the bug number we can organise that 15:23:40 acolwell: discussion for 18960 is to figure out how to generate the IDs 15:23:48 ... in some cases can be the track ID in the media 15:24:04 ... for single video/audio track media we need to define the behaviour 15:24:19 ... two proposals, one is to generate IDs, one is to use the first 15:24:44 acolwell: 19531, this is a recently filed bug about detecting which MIME types are actually supported by MSE 15:24:44 cyril has joined #html-media 15:24:55 ... proposal in the bug and discussion about the name and semantics of the method 15:25:03 ... just need to nail this down, shouldn't take too long 15:25:16 acolwell: so those are the ones in the clarification category 15:25:21 ... in the new features category 15:25:34 +Mark_Vickers 15:25:42 acolwell: 18962, a mechanism for rate limiting where the tag can tell the app to slow down 15:25:45 Mark_Vickers has joined #html-media 15:25:54 ... not much discussion about this, discussion for TPAC is if we need this in v1 15:26:10 ... and if yes to come up with a proposal 15:26:15 ... questions so far? 15:26:22 paulc: nobody on the queue 15:26:34 -Mark_Vickers 15:26:43 .. btw updated the TPAC wiki to mention 18971 - we might have a session to deal with misc bugs 15:26:46 +Mark_Vickers 15:27:03 acolwell: 18962, this is making progress on the XHR integration with MSE 15:27:13 ... since the last time we discussed there is progress on the webapps 15:27:23 ... with people starting to rally around the microsoft proposal 15:27:39 ... there is some discussion about how the W3C spec will get updated 15:27:48 ... and behaviours about what MSE should do with this object 15:28:02 acolwell: 18709, about SourceBuffer.remove() that i recently added 15:28:15 ... need to discuss the behaviour if remove is requested for current playback range 15:28:30 ... not clear what to do if the app wants to remove content at the current position 15:29:06 acolwell: 17006, this is about specifying the track language and kind when not available 15:29:29 adrianba: i will make a proposal prior to TPAC so we have something concrete to discuss 15:30:06 ... i think we know what the problem is and what is needed - we just need someone to make a concrete proposal and i will do that 15:30:19 Mark_Vickers has joined #html-media 15:30:43 acolwell: 17002, this is how to figure out which buffer is associated with a track - think we have a rough proposal that we need to finalise 15:31:03 ... track might not have an ID and we need to figure out what to do as a workaround 15:31:36 acolwell: 17094, this is to talk about MPEG2-TS - get some face to face discussion on this 15:31:46 ... there has been some email discussion but some face to face discussion might help it go easier 15:32:05 paulc: do the editors know how long it will take to discuss these? will 90 mins be sufficient or will we need more time 15:32:24 acolwell: i think we might need more - can we have an optional extension? 15:32:43 paulc: we won't necessarily be able to tell until we see what slots are needed 15:32:55 ... interestingly many a11y people will be in indieui 15:33:03 ... which in the past we spent a lot of time on 15:33:11 ... i don't think that will happen this time 15:33:30 ... if there is time we might want to extend the slot but we'll need to do that there 15:33:36 F2F topics: http://www.w3.org/html/wg/wiki/TPAC2012#Topics 15:33:40 q+ 15:33:52 acolwell: we should also take a poll of people at the meeting to discuss the highest priority items 15:33:55 -Mark_Vickers 15:34:20 paulc: pierre, your items, first audio splicing 15:34:24 MSE audio splicing: http://lists.w3.org/Archives/Public/public-html-media/2012Oct/0052.html 15:34:31 pal: the idea here is that given the scope of MSE and use cases considered 15:34:47 ... it would be good to try to look at a topic previously frustrating 15:35:01 ... which is the splicing of audio or transition of audio streams at splice points 15:35:09 ... for video you transition at video frame boundary 15:35:29 ... but audio is more difficult, for example if the audio levels are different 15:35:33 +Mark_Vickers 15:35:41 ... for encoded audio the frame boundaries might not line up 15:35:59 ... so goal is to capture some practices that have been learned and share with implementers 15:36:24 ... i think it would be help to have something along those lines provided to MSE implementers 15:36:26 q+ 15:36:54 ack adrian 15:37:32 adrianba: is this proposal for informative text or should part of it be normative? 15:37:53 pal: that's up to this group - either could work, i don't have an extremely strong opinion 15:38:10 ... just listing them will reduce poor implementation and lack of interop 15:38:30 adrianba: if this would affect interop it sounds like there would be normative parts 15:38:52 acolwell: i've only done a high level review - seems like some of the parts of splicing encoded data would be good to be normative 15:39:01 ... current text is light on this topic 15:39:13 ... but haven't drilled into which text should be normative 15:39:23 paulc: do we want to do anything on this before the meeting? 15:39:33 acolwell: i plan to read the doc more carefully 15:39:44 ... i haven't spent much time thinking about audio 15:39:59 pal: my recommendation is that this be included or be considered before FPWD 15:40:13 ... the longer we wait the more likely decisions that people might regret could be made 15:40:28 ... some might not be relevant, some might need more detail, i'm happy to help 15:40:35 ... but it should be addressed before FPWD 15:40:55 paulc: what's the rationale for that? is it because of the scope 15:41:13 pal: i think implementers might take decisions 15:41:15 q+ 15:41:22 ... that might be hard to undo 15:41:45 paulc: for fpwd you only have to have agreement to publish not to that on the content 15:41:52 pal: it's better to have a better FPWD 15:42:11 paulc: i'm not arguing against, just trying to understand 15:42:11 ack adrian 15:42:11 Mark_Vickers has joined #html-media 15:42:19 q+ 15:43:19 ack Mark 15:43:26 adrianba: i think we should prioritise identifying the normative parts for the FPWD so that the scope is set 15:43:34 ... that's the most important activity for this 15:44:06 Mark_Vickers: it's not clear which parts are authoring and client parts, could that be clearer? 15:44:16 acolwell: i think they're all UA requirements 15:44:28 Mark_Vickers: in 2.1 it says content should be authored 15:44:36 pal: it was meant as a client recommendation 15:44:45 ... you're right that there are two points that menton authoring 15:44:53 ... but that is meant as a help to the reader 15:45:09 ... but this was meant as client behaviour which would then drive authoring behaviour 15:45:14 Mark_Vickers: okay, thanks 15:45:34 pal: important part is that unless some of these are documented for client authors will not know how to get the desired outcome 15:45:48 Mark_Vickers: i think there's a lot of experience to show that this has caused problems in the past 15:45:55 ... and i support the idea of getting this out earlier 15:46:07 paulc: next item is timestamp offset accurary 15:46:13 See: http://lists.w3.org/Archives/Public/public-html-media/2012Oct/0054.html 15:46:26 pal: before that, part of outcome of splicing is benefit of adding flag to each buffer appended 15:46:38 ... so may need to add a flag to buffers but we can discuss as part of document 15:46:59 paulc: okay, let's move on to timestamp offset accuracy, which you've had one reply to 15:47:06 pal: this has cause problems in the past 15:47:20 ... offsets are often specified in sample durations 15:47:47 ... unfortunately floating point representation cannot in general represent fractions because of rounding errors 15:48:16 ... this is a tricky area and direction i've seen is to express offset and positions as rational numbers instead of floating point numbers 15:48:23 ... MSE uses double for the offsets 15:48:33 q++ 15:48:44 ... timestampOffset is a double 15:48:56 ... i think it should be expressed as a rational number without ambiguity 15:49:13 ... how the implementation uses that is different and spec might not talk about that 15:49:33 paulc: by rational do you mean specifying numerator and denominator 15:49:54 pal: that's one way, alternative is timescale (ratio) and then multiple of timescale 15:50:10 ... by rational i mean the ratio between integers 15:50:11 q? 15:50:37 pal: e.g. ISO BMFF uses two integers 15:51:07 ... this is a topic that caused issues and i want to understand if this is an issue here and then figure out a solution 15:51:10 q+ 15:51:30 MartinSoukup has joined #html-media 15:51:38 ack + 15:52:17 strobe: timestampOffset is the last thing applied 15:52:31 ... i think a lot of past problems with precision have come for duration calculation 15:52:51 ... we need a common way of expressing all the possible inputs 15:53:02 ... even if you had very precise ways of specifying for one file 15:53:21 ... you might be using different files and you need the precision for all of them 15:53:32 q+ 15:53:43 ack adrian 15:53:47 ... since this is just for offset not for duration i don't think it will cause a problem based on my experience 15:54:19 q- 15:54:46 adrianba: please could pal file bugs in bugzilla, which we'll use to drive the discussion in the meeting 15:55:03 paulc: we've dealt with these topics, okay? 15:55:05 pal: yes, thanks 15:55:06 ack strobe 15:55:27 strobe: one quick question, the states in which you can add and remove sourcebuffers 15:55:33 ... i think we discussed this in the past 15:55:43 acolwell: i think we said you could do this at any time 15:55:58 ... at the moment chrome doesn't support that because of limitations in the engine 15:56:14 ... i don't know if we want to support that in the API 15:56:19 ... but for now chrome doesn't support that 15:56:24 strobe: okay, thanks 15:56:34 paulc: think we've covered all of the agenda 15:56:42 ... we have a plan in place for a good discussion at tpac 15:56:49 ... is there other business to discuss? 15:57:03 paulc: future meeting schedule 15:57:12 ... won't be EME next week 15:57:24 ... schedule would normally be for a MSE meeting right after TPAC 15:57:35 ... i doubt we'll want to meet so soon after the F2F 15:57:42 ... we want to give the editors time 15:57:48 ... we'll discuss this at the meeting 15:57:58 ... i'm also on vacation during november 15:58:05 ... so we need to discuss who will drive the meetings too 15:58:11 ... we'll discuss at tpac 15:58:29 TOPIC: adjournment 15:58:36 paulc: meeting is adjourned 15:58:44 ... thanks to the editors for analysis 15:58:50 -johnsim 15:58:51 -Mark_Vickers 15:58:52 ... let's hope for the same on EME 15:58:52 -joesteele 15:58:52 -Clarke 15:58:53 zakim, drop me 15:58:53 -MartinSoukup 15:58:53 -pal 15:58:53 Matt is being disconnected 15:58:54 -Matt 15:58:55 -strobe 15:58:58 -Aaron_Colwell 15:59:02 -[GVoice] 15:59:05 zakim, bye 15:59:05 leaving. As of this point the attendees were +1.650.525.aaaa, pal, Matt, +1.415.867.aabb, paulc, adrianba, [GVoice], strobe, [Microsoft], johnsim, Aaron_Colwell, +1.303.661.aacc, 15:59:05 Zakim has left #html-media 15:59:09 ... Clarke, +1.613.491.aadd, MartinSoukup, +1.425.202.aaee, ddorwin, +1.408.536.aaff, joesteele, Mark_Vickers 15:59:10 rrsagent, make minutes 15:59:10 I have made the request to generate http://www.w3.org/2012/10/23-html-media-minutes.html adrianba 15:59:16 rrsagent, make logs public 16:06:02 MartinSoukup has joined #html-media 16:06:22 adrianba has joined #html-media 18:13:40 ddorwin has joined #html-media 19:14:15 adrianba has joined #html-media