Meeting minutes
RRSAgent: make log public
RRSAgent: draft minutes
This meeting
gkatsev: [goes over agenda]
Interaction between tts:writingMode and tts:direction on paragraph element. w3c/ttml2#1211
gkatsev: we talked about this a month ago
pal: plan was going to file new issues
… a new issue was filed
… but there's a disagreement again
… someone needs to take this on and do it before end of the year
Remove application of tts:unicodeBidi to tt:p element
-> Improve interoperability of tts:direction on tt:p with CSS3 implementations
atai: a step forward would be to get a concrete proposal and then get consensus that way
pal: I agree with title of issue 1212 but description isn't clear
pal: I'll create one or two pull requests
cyril: we can work on it together
atai: Nigel assumes no one is using a XSL-FO processor
… I think ttpe is using one
… does a joint meeting with CSSWG necessary to conclude this?
pal: I think a PR would be helpful to move forward regardless
gkatsev: a PR would be nice to make progress
incoming liaison letter from MPEG regarding ISO/IEC 14496-30
<atsushi> https://
<atsushi> > ISO JTC1/SC 32 (Class C Liaison)
<atsushi> > XML and Dublin Core Ivan Herman Jim Melton
cyril: going over liaison
… people had questions on how to stream TTML with multiple periods in DASH?
… MPEG is seeking clarification with TTWG around usage
atai: would be useful to have Mike Dolan on the call
cyril: request is what terminology should be used
pal: why mention timeline, we should use document time?
cyril: timeline is well understood in MPEG
… a TTML has a timeline and you place things on the timeline
… the mp4 has a timeline
… anchor TTML to mp4
pal: don't use timeline for TTML.
… Say here's how to map document time in TTML to MPEG time
… All it has is time offsets
cyril: still, there's some ambiguity. There's nested time containers in TTML.
pal: the nesting of temporal expressions is just syntactic sugar
… everything translated to start and end in document time
cyril: the term Document Time doesn't seem to be defined in TTML2
pal: document times are expressed on the document temporal coordinate space
… times come out as offsets
atai: the document needs to say what the reference for those offsets are
cyril: [presents proposed changes]
atai: important to circulate outcome to implementers to see if they can understand it
cyril: MPEG sent similar liaisons to all types of organizations
… so implementers can understand it
<atsushi> (I'm operating webex client on tablet, and it seems I've touched wrong line.... sorry for mis-operation for muting noise.)
pal: a TTML decoder returns temporal coordinates where each ISD is
… and these temporal offsets are the interface
… How do you take these temporal coordinates and map them to ISOBMFF timeline?
… This mapping is critical to sync up with audio and video
cyril: I see what you're saying, I'm not sure how to translate it to text
… that's understandable by implementors
pal: make a formula for mapping temporal offsets in seconds into the ISOBMFF timeline
… it's the same formula for each TTML document
… regardless of the ordering in the TTML track
cyril: how do I refer to this time offset in TTML spec
pal: I think it's called time coordinates
gkatsev: writing up something and sending it to the group might be a good way to progress
ending meeting
gkatsev: [wrapping up]
… [mentioned thinking about process2020, patent policy 2020, and default branch name for next time]
RRSAgent: draft minutes
RRSAgent: make minutes v2
RRSAgent: make minutes v2