<kaz> scribenick: kaz
Chris: We have a few topics
today:
... update and next step for media production use cases,
... an update from the Media Timed Events TF,
... following up on last month's Web of Things call,
... and Bullet Chatting TF.
... AOB?
(none)
Chris: There are some comments from Nigel on Garrett's pull request
<cpn> https://github.com/w3c/media-and-entertainment/pull/33
Chris: We discussed whether or not we
should create a separate repo,
... so that we can gather related documents in one place.
... So we have created a repo to use
<cpn> https://github.com/w3c/me-media-production
Chris: It's empty at the moment
though,
... and we would like to move the initial document to that
repo.
... In doing that we should also take in account Nigel's
comments.
Garrett: That's a good idea
Nigel: We should transfer the existing issues/PRs to the new repo.
Chris: I will look into how to do that.
Garrett: There several issues there, the main one is about describing the use cases.
Nigel: It's a good time to solicit
questions, and write some clear motiviating use case
descriptions.
... We should explain the outcomes we want to achieve, the use
cases,
... and then any resulting gaps, and prioritise them in order of
importance.
Chris: I agree. Once we have this in
the new repo we can add to it, show it to people, and I hope gather
further contribution.
... If Pierre can join later, I'll ask him for an update.
Chris: This is an update on the TF work.
<cpn> https://docs.google.com/presentation/d/1nWEG-LNZiNt0EQV91AryzmolJ-KBJYKJdgNatCMNIy8/edit
Chris: To recap,we had a goal to
improve support for timed events related to audio/video media on
the Web.
... This extends the existing TextTrackCue support to general data
cues.
... There was some media industry interest, around inband
events.
... We identified some gaps, including timing accuracy of rendering
content synchronization.
... The main outcomes so far: We published an IG note with use
cases and gap analysis.
Chris: Also started WICG DataCue
incubation following TPAC 2018.
... Current status: I'd like to complete the next revision of the
IG Notes.
... Thanks to everyone who provided feedback, I have made a new
draft.
... I would like to get further review before we finalize it.
... I'll follow up with people offline, and share with the IG.
Chris: We have two proposed changes
to the HTML spec.
... One is changing TextTrackCue end time representing end of
media: https://github.com/whatwg/html/issues/5297
... use value of "Infinite".
... The second proposal is for text track cue event timing
accuracy: https://github.com/whatwg/html/issues/5306
... I'm working on this now. Initial response from Philip
Jagenstedt was positive, so I'll draft some wording for
review.
... There's also implementation work by Chromium team happening
now.
... Issue 576310: https://bugs.chromium.org/p/chromium/issues/detail?id=576310
... Issue 1050854: https://bugs.chromium.org/p/chromium/issues/detail?id=1050854
... Two issues there: one is for timing accuracy, the other relates
to some events not firing when they should be.
... As next steps, I'm trying to restart the activity on
DataCue.
... I have been talking to the people from DASH-IF. They have a
parallel activity on DASH eventing.
... They have calls every 2 weeks on Friday afternoon and have
invited people from W3C to join.
... I myself joined 2 weeks ago.
... If you would like to join it, you're welcome, please contact me
for the details.
... (next call on Friday, March 6)
... The next Media Timed Events TF is call on March 16
... I'm also having discussions with some of the implementers, as
we need to get their engagement
... and bring them into the activity.
... I'll have more to report on March 16th, and we can discuss
further work for the TF.
... For example, there was discussion during the Media WG meeting
at TPAC
... about developing cue rendering pipeline idea.
Media WG discussion during TPAC
Chris: Basically, from MEIG's point
of view we want to hand over the work to the WICG and close the TF
if there's no more to do.
... But in WICG we need the relevant people around the table to
make progress.
... Any questions/comments?
(none)
(Pierre joins)
Chris: We talked about media
production briefly,
... I mentioned creating a new repo and migrating the resources to
it.
... Do you have anything to add about conversations you've had?
Pierre: I'm trying to involve
relevant people, setting up a separate call,
... but so far not have musch success.
... Nothing to report yet.
Chris: OK. I should also mention the
video editing WICG topic raised by Microsoft.
... Perhaps we can invite them in to talk about it.
https://github.com/WICG/video-editing
<cpn> scribenick: cpn
<kaz> WoT use cases
<kaz> WoT architecture issues
<kaz> WoT thing description issues
Kaz: There are three pieces:
... 1. the WoT WG are generating use cases on GitHub
... 2. and there are some open issues
... 3. also there's an ongoing parallel discussion with the Singaporean government about surveillance cameras support
... but this should be separate from the M&E video streaming
use cases.
... As someone who's across both groups, I can generate some
initial use cases, then invite MEIG people to the WoT use case
discussion next week
Chris: I can help you prepare that.
Kaz: We can share some initial draft as basis for initial discussion.
Igarashi: What is the agenda for the next joint call?
Kaz: The suggestion wasn't to have
another joint call, but invite MEIG people to the WoT architecture
discussion.
... We can have another joint call later.
Chris: We can draft something to
share with MEIG and invite contribution.
... Also reach out to people not on the call today.
... I think we need more input from our members, to bring use cases
that are relevant.
Kaz: If you're interested, please join the WoT architecture call next week.
Chris: I can do that.
Igarashi: Is the expected input from MEIG or individual members?
Kaz: Individual members is OK, all are welcome.
Chris: The Web & TV IG produced home network requirements, may be useful to review.
Requirements for Home Networking Scenarios
<kaz> Kaz: The WoT architecture has two calls on Thursday: 1. 2am EST, 7am GMT, 8am CET, 4pm JST and 2. 11am EST, 4pm GMT, 5pm CET, 1am+1d JST
Chris: We can review which are still relevant, but need people from those organisations to contribute to the work ideally.
<kaz> WoT Architecture wiki (including the webex info)
<kaz> Kaz: The WoT WG are looking at home network use cases at the moment.
<kaz> scribenick: kaz
Chris: Will give a progress update on the mailing list, please participate!
Chris: One of the outcomes from our last discussion was to look at the technical architecture.
Bullet Chatting Logical Architecture and Data Flow Diagam
Huaqi: [Slide 2] We've worked on the
architecture diagram and data flow chart.
... [Slide 3] Here's the bullet chatting local architecture
diagram.
... There are two main modules in the client, the Bullet Chatting
Data Module and the Bullet Chatting Rendering Module.
... On initialisation, the client loads a bullet chatting data
format file from the server.
... The file includes colour, font size, image, animation
formatting data. It also includes the bullet chatting data.
... When running, the client will also get incremental bullet
chatting data via a websocket or polling.
... The rendering module needs to support three scenarios:
communication, video on demand, live streaming, and
non-video.
... In the video on demand scenario we also need to support
synchronisation to the timeline.
... When the user inputs the bullet chatting, the client sends the
data to the server.
Nigel: There's synchronisation with the timeline in video on demand. Is this also the case for live?
<xfq> See also: http://assets.processon.com/chart_image/5e4f97dbe4b0c037b5f82fc5.png
Nigel: Can you pause and rewind the live streaming?
Huaqi: There's no synchronisation with live streaming.
Chris: I guess with a live chat, it's
not possible to synchronise to give the same experience to all
viewers
... because different people may experience different latencies in
the video streaming.
Nigel: I'm thinking of the case where
there's a live rewind window, in the HLS or DASH manifest, so you
can go backwards.
... In which case you would want to synchronise to the media, even
though the chat is delivered live.
Chris: From the video on demand bullet chat examples I've seen, it does that, not sure about live.
Kaz: So the expectated service here is rather recorded video, where the users can add bullet chat annotations on the video, like YouTube video?
Huaqi: Yes.
... [Slide 4] In the next data flow chart, rendering bullet
chatting in file.
... On the client side, after initialization the client will query
the bullet chatting data file from the server,
... the server obtains this from the database and returns it to the
client.
... If there is data in the file, the client will render the bullet
chat.
... [Slide 5] Next, sending bullet chatting.
... On the client side, after initialisation, the user will input
bullet chatting data.
... The client does some local filtering for sensitive words. If
it's ok it's sent to the server.
... The server also applies filtering, and if it's OK the data is
inserted in the database.
... Then, we broadcast the bullet chatting data to all
clients.
... [Slide 6] Lastly, rendering incremental bullet chatting.
... When running, the client will receive incremental bullet
chatting data via websocket or polling.
... The server gets bullet chatting data from the client, inserts
it in the database, and broadcasts it to all clients.
... So the clients receive all the bullet chatting data, and if
there is data will render it.
... Any questions on these data flows?
Chris: Thank you for preparing the architecture diagrams, this is very helpful.
<xfq> See also: http://assets.processon.com/chart_image/5e4fa83ce4b0362764fb5c58.png
Pierre: On the first slide, which
shows the browser,
... in the bullet chatting local architecture diagram,
... who provides the bullet chatting data module? Where it comes
from?
Huaqi: It's provided by the application, which could be a native app or web app.
Pierre: We're out of time but want to continue the discussion.
Chris: I suggest having another call
soon. Waiting another month might be too long,
... as I would like us to make more progress.
... We'll discuss offline when to schedule it.
... The next IG call will be April 7, also the MTE TF call on March
16.
... We'll announce a date for continuing bullet chatting discussion
soon.
... Any last comments or questions?
(none)
Chris: Thanks everyone!
[adjourned]