16:03:21 <RRSAgent> RRSAgent has joined #tt
16:03:21 <RRSAgent> logging to https://www.w3.org/2020/11/05-tt-irc
16:03:43 <cyril> cyril has joined #tt
16:03:54 <gkatsev> Meeting: Timed Text Working Group
16:03:56 <gkatsev> Chair: Gary
16:04:15 <gkatsev> Agenda: https://github.com/w3c/ttwg/issues/157
16:04:21 <atai> atai has joined #tt
16:04:32 <gkatsev> RRSAgent: make log public
16:04:36 <gkatsev> RRSAgent: draft minutes
16:04:36 <RRSAgent> I have made the request to generate https://www.w3.org/2020/11/05-tt-minutes.html gkatsev
16:05:25 <pal> pal has joined #tt
16:05:33 <gkatsev> Topic: This meeting
16:07:19 <gkatsev> scribe: gkatsev
16:07:31 <gkatsev> gkatsev: [goes over agenda]
16:10:06 <atai> q+
16:13:14 <gkatsev> Topic: Interaction between tts:writingMode and tts:direction on paragraph element. w3c/ttml2#1211
16:13:19 <gkatsev> gkatsev: we talked about this a month ago
16:13:24 <gkatsev> pal: plan was going to file new issues
16:13:28 <gkatsev> .. a new issue was filed
16:13:33 <gkatsev> .. but there's a disagreement again
16:13:37 <gkatsev> .. someone needs to take this on and do it before end of the year
16:13:55 <gkatsev> -> https://github.com/w3c/ttml2/issues/1212 Remove application of tts:unicodeBidi to tt:p element
16:14:07 <gkatsev> -> -> https://github.com/w3c/ttml2/issues/1213 Improve interoperability of tts:direction on tt:p with CSS3 implementations
16:14:29 <gkatsev> atai: a step forward would be to get a concrete proposal and then get consensus that way
16:14:48 <gkatsev> pal: I agree with title of issue 1212 but description isn't clear
16:14:59 <gkatsev> pal: I'll create one or two pull requests
16:15:46 <gkatsev> cyril: we can work on it together
16:15:57 <gkatsev> ack atai
16:16:24 <gkatsev> atai: Nigel assumes no one is using a XSL-FO processor
16:16:41 <gkatsev> .. I think ttpe is using one
16:17:40 <gkatsev> .. does a joint meeting with CSSWG necessary to conclude this?
16:17:55 <gkatsev> pal: I think a PR would be helpful to move forward regardless
16:18:29 <gkatsev> gkatsev: a PR would be nice to make progress
16:19:32 <gkatsev> Topic: incoming liaison letter from MPEG regarding ISO/IEC 14496-30
16:20:43 <atsushi> https://www.w3.org/2001/11/StdLiaison#I
16:21:12 <atsushi> > ISO JTC1/SC 32 (Class C Liaison)
16:21:13 <atsushi> >    XML and Dublin Core     Ivan Herman     Jim Melton
16:25:56 <gkatsev> cyril: going over liaison
16:26:22 <gkatsev> .. people had questions on how to stream TTML with multiple periods in DASH?
16:26:48 <gkatsev> .. MPEG is seeking clarification with TTWG around usage
16:28:43 <gkatsev> atai: would be useful to have Mike Dolan on the call
16:28:59 <gkatsev> cyril: request is what terminology should be used
16:31:57 <gkatsev> pal: why mention timeline, we should use document time?
16:32:09 <gkatsev> cyril: timeline is well understood in MPEG
16:32:23 <gkatsev> .. a TTML has a timeline and you place things on the timeline
16:32:28 <gkatsev> .. the mp4 has a timeline
16:32:34 <gkatsev> .. anchor TTML to mp4
16:32:40 <gkatsev> pal: don't use timeline for TTML.
16:32:53 <gkatsev> .. Say here's how to map document time in TTML to MPEG time
16:33:07 <gkatsev> .. All it has is time offsets
16:33:46 <gkatsev> cyril: still, there's some ambiguity. There's nested time containers in TTML.
16:34:36 <gkatsev> pal: the nesting of temporal expressions is just syntactic sugar
16:36:03 <gkatsev> .. everything translated to start and end in document time
16:36:49 <gkatsev> -> https://www.w3.org/TR/2018/REC-ttml2-20181108/#semantics-media-document-timing document time in TTML2
16:38:49 <gkatsev> cyril: the term Document Time doesn't seem to be defined in TTML2
16:39:22 <gkatsev> pal: document times are expressed on the document temporal coordinate space
16:40:49 <gkatsev> .. times come out as offsets
16:41:03 <gkatsev> atai: the doucment needs to say what the reference for those offsets are
16:41:19 <gkatsev> s/doucment/document/
16:41:46 <gkatsev> cyril: [presents proposed changes]
16:52:47 <gkatsev> atai: important to circulate outcome to implementers to see if they can understand it
16:53:02 <gkatsev> cyril: MPEG sent similar liaisons to all types of organizations
16:53:08 <gkatsev> .. so implementers can understand it
16:54:55 <atsushi> (I'm operating webex client on tablet, and it seems I've touched wrong line.... sorry for mis-operation for muting noise.)
16:54:57 <gkatsev> pal: a TTML decoder returns temporal coordinates where each ISD is
16:55:29 <gkatsev> .. and these temporal offsets are the interface
16:55:40 <gkatsev> .. How do you take these temporal coordinates and map them to ISOBMFF timeline?
16:56:24 <gkatsev> .. This mapping is critical to sync up with audio and video
16:56:49 <gkatsev> cyril: I see what you're saying, I'm not sure how to translate it to text
16:56:56 <gkatsev> .. that's understandable by implementors
16:57:41 <gkatsev> pal: make a formula for mapping temporal offsets in seconds into the ISOBMFF timeline
16:57:51 <gkatsev> .. it's the same formula for each TTML document
16:57:59 <gkatsev> .. regardless of the ordering in the TTML track
16:58:12 <gkatsev> cyril: how do I refer to this time offset in TTML spec
16:58:21 <gkatsev> pal: I think it's called time coordinates
16:59:17 <gkatsev> gkatsev: writing up something and sending it to the group might be a good way to progress
17:00:55 <gkatsev> present: gkatsev, pal, cyril, atai, atsushi
17:01:00 <gkatsev> regrets: Nigel
17:01:36 <gkatsev> gkatsev: [wrapping up]
17:01:54 <gkatsev> .. [mentioned thinking about process2020, patent policy 2020, and default branch name for next time]
17:02:07 <gkatsev> RRSAgent: draft minutes
17:02:07 <RRSAgent> I have made the request to generate https://www.w3.org/2020/11/05-tt-minutes.html gkatsev
17:04:00 <gkatsev> RRSAgent: make minutes v2
17:04:00 <RRSAgent> I have made the request to generate https://www.w3.org/2020/11/05-tt-minutes.html gkatsev
17:05:48 <gkatsev> i/gkatsev: [wrapping up]/Topic: ending meeting
17:05:50 <gkatsev> RRSAgent: make minutes v2
17:05:50 <RRSAgent> I have made the request to generate https://www.w3.org/2020/11/05-tt-minutes.html gkatsev
17:06:36 <gkatsev> scribeOptions: -final -noEmbedDiagnostics
17:06:42 <gkatsev> rrsagent, make minutes v2
17:06:42 <RRSAgent> I have made the request to generate https://www.w3.org/2020/11/05-tt-minutes.html gkatsev
17:09:12 <gkatsev> atsushi: do you know how Nigel gets the text format minutes for the email?
17:09:33 <gkatsev> Zakim: end this meeting
17:17:53 <gkatsev> RRSAgent: excuse us
17:17:53 <RRSAgent> I see no action items