<scribe> scribe: tidoust
ChrisN: I wanted us to look at
outcomes from TPAC meetings, around color (HDR and WCG) that
Pierre will report on, CMAF and Media Capabilities and MSE,
Media Integration Guidelines for which we need some next steps,
and commonalities between WebRTC architecture and stream
media
... We're running a survey to find a possibly better meeting
time
ChrisS: New in the Group. In Broadcast, interested in still graphics signaling, integration into ATSC 3 and HbbTV hybrid mode where they may be pulling from the Web
ChrisN: OK, let's come back to that.
Kaz: Maybe not for today, but we
might want to look into the MiniApps proposal at some
point.
... Proposal for a new platform for Web apps, which may affect
media playback as well.
... We had a tutorial on MiniApps today for the Japanese Members and there were 65 attendees there
... so there seems to be interest there
ChrisN: If there are specific
aspects that are media/streaming related, we should discuss
that, indeed.
... Let's follow-up offline.
<cpn> Chris Needham's slides for today's topics
Pierre: Inaugural call last week.
Outcomes: discussion will happen in the Color on the Web CG,
next meeting on Dec 9 at 6am UTC. I just sent a calendar invite
to the group's reflector.
... We expect a bunch of technology demos on how the Web
(WebGPU, videos) can better handle HDR and WCG.
ChrisN: This IG is interested in
media industry requirements in general, but given that color
support is broader in scope, it makes sense to do it in a
separate CG.
... I would expect that activity to be looking at static image
support
... I don't think that we have something specific on that for
now.
... An initial report has been prepared in the Color on the Web
CG.
... My personal thought is that we would be extending the
responsive images mechanism.
... So that the browser can choose which image to render.
<kaz> ITU-T H.Sup19 : Usage of video signal type code points
ChrisS: I note ITU-T
standard that consolidates signaling for video.
... 37 standards that need to be consolidated.
... Having a single document would be good
Leonard: One of the things we did in the CG is establish a formal liaison with the ICC, where some of this work also happens.
ChrisN: Any document that you could share on that, Chris?
ChrisS: I'll grab that and share.
ChrisN: I would suggest to focus the discussions in the CG itself. We don't necessarily have all of the people interested in that space today.
Leonard: You're also correct that static images are being addressed by the Color on the Web CG as well.
Pierre: Again, if you're interested in Color on the Web, please JOIN the CG. Just one click away!
ChrisN: We had a call last month where guys from Chrome team clarified how technologies work together. Chris Cunningham put together an explainer document as a result of this discussion.
ChrisN: I invite people to review
that explainer
... The possiblity to use a polyfill library was also mentioned
to account for the different CMAF capabilities.
... I don't know yet if people have looked into it already and
whether people are willing to work on the polyfill.
Will: I'm involved on the WAVE side, but not aware of anyone willing to contribute to the polyfill. WAVE does not develop software. We need to find some mechanism to develop the software, perhaps look for sponsors, etc.
ChrisN: I think you're right, it
needs some engineering effort.
... It could ultimately be a thing that is an open source
project.
Will: WAVE was thinking of an
open source github project. Problem is maintenance, e.g. diff
and update every 6 months.
... It's more difficult to find people willing to commit to
it.
ChrisN: Would it be useful to reach
out to Media Player libraries people? A common library could be
useful
... It does seem that we need to answer some of these
questions.
... We need to do some implementation work there.
... That could be a good way to follow up.
... Next part is CMAF in MSE Byte Stream Format Registry. There
is a document being worked upon in the WAVE project.
... Open questions on whether to merge with the ISO BMFF Byte
Stream Format spec or whether to have a distinct Byte Stream
Format spec.
... Whether browsers will stricly validate the content or take
a more liberal approach.
... I know that John Simmons is leading that activity.
... The other thing that I'd like to point out is that we have
the DataCue activity where we look at emsg box support.
... Some questions e.g. around how the events get mapped to the
media timeline
... We have a monthly call, next one of those will be in 2-3
weeks from now.
... Some specific technical work that we need to do to figure
out how timing relates to MSE interfaces.
... How much do we want to do in-band vs. out-of-band.
... Or handled separately from the media processing
... If you're interested to contribute, let me know
... At the end of the meeting, we said that we'd organize a
follow-up meeting between W3C and CTA WAVE. No date confirmed
for now, we keep you updated.
ChrisN: We talked about this during
the TPAC meeting. Good input from the Chrome team. We would
also like to get input from other browser vendors and
integrators in embedded devices.
... Should we flesh out some content in the doc already? Or do
we want more input from browser vendors first?
... More content would perhaps help gather additional
feedback.
... Certainly happy to point people from Apple and Firefox at
the issues to get more responses.
... If people have input from TV embedded browsers, that kind
of input would be very welcome as well.
ChrisN: We had a really interesting
conversation with the WebRTC WG, where they presented their
vision of where they are going.
... Two "parallel" worlds: WebRTC world, and what we have for
streaming delivery with MSE, HTMLMediaElement. As we introduce
the capabilities as the proposed Insertable Streams, APIs such
as WebCodecs, and others that give you access to low-level
interfaces, are there particular use cases that we're
interested in looking at?
... How are we going to make use of these additional
capabilities that browser vendors are introducing?
... It occurs to me that this would be a good way to review the
proposals to make sure that they meet our needs.
... Anyone willing to share experience in this area?
... We'll keep track on development, but it does not feel like
something that people on this call today have a particular need
of.
ChrisN: We have been thinking about
our call schedule, and how the timing is favorable for Europe,
and more difficult for others.
... The question is: should we alter the meeting schedule to
make it at more friendly times for other timezones?
... We could cycle between times.
... Also, regarding summer/winter times, should we keep the
time constant in UTC, and thus in Asia?
... There is an ongoing survey, please repond to it.
... Most people who responsded indicated that they are fine
with current timing, but 3 people, based in Asia I believe,
indicated that this makes it difficult for them to
participate.
Pierre: Have you set a deadline for responses?
ChrisN: This meeting, but I don't actually remember whether I said so in the message I sent to the mailing-list.
Pierre: You could send a reminder today and give them until the end of the week.
ChrisN: Yes, let's do that.
Igarashi: How about asking this
call's attendees?
... Preference for rotating or not rotating?
Takio: Fixed time is useful for me (easier to set the schedule) and current time is acceptable.
ChrisN: The idea that we share the pain between us seems fair. I think that is what is driving that discussion.
Igarashi: How about US people?
ChrisN: The survey response suggested that people were OK.
Pierre: In the reminder, please
insist that people need to voice their difficulties. We cannot
take a good decision if we don't hear about people.
... I guess we could just give cycling times a try
ChrisS: Rotating is fine from my perspective.
ChrisN: Proposed times would be difficult for people in the East Coast though
Leonard: Pretty much "business as usual" in international standards commitees
Hoya: I think this time slot is good for us because it will be not interrupted by other things in working time.
<igarashi> i would know the view who has difficultiy with current time slot firstly
<igarashi> my preference is not rotating time slot
ChrisS: how are we going to
carry static graphics and render them consistently across
possibly multiple devices.
... Not much information from me, but I'm willing to hear about
that.
... In linear broadcast, you may render images on top of video,
and you need to understand what are the display capabilities to
pick up the appropriate content (e.g. HDR/SDR)
... That would be application to our teams at Sky.
... Once we get more information, we may provide more input of
how it affects our workflow
ChrisN: I would suggest to do that as part of our activities in the Color on the Web CG.
<igarashi> +1 to hoya-san on not interrupting day work
Leonard: I'm pretty sure we did a report on static image formats in the Color on the Web CG.
ChrisS: There's a GitHub document that I've seen. The one I saw may need a bit more details. E.g. it does not mention PQ in some elements.
<inserted> High Dynamic Range and Wide Gamut Color on the Web
ChrisN: I produced this document a
few years ago. This was initially just an internal document for
my BBC colleagues to figure out what we needed. Then I shared
it with the Color on the Web CG which adopted it as a CG
deliverable.
... Since then, I hardly touched on it. Chris Lilley expanded
it.
... I certainly agree that it lacks details.
Pierre: I suggest that we put that
on the agenda for our first meeting.
... More importantly, we really need a practical example.
Someone who tries to do what it wants to do and shares what
breaks.
ChrisS: We can do a lot of
that. With the Olympics for instance.
... That's the biggest hole that we have right now. We can
provide some examples.
Pierre: If you can drive us through
this during next CG call, that would be great;
... a lot of these documents are very aspirational. At the end
of the day, it would be good to focus on what people want to do
right away.
... Actual code, e.g. actual canvas code.
Leonard: +1, and "here is what I try to accomplish".
Pierre: We need to identify specific gaps.
ChrisN: This feels like a good
agenda item for this next meeting.
... Open question on whether this document should be dropped or
updated, and whether more editors could help.
... I plan to join next call.
ChrisS: If we could include a table with still graphic format, how HDR support would be signaled, that would be easier to absorb.
ChrisN: That's doable, the key is to
have someone who could act as editor. I'm not sure I'm in a
position to volunteer to continue to do that.
... In principle, I agree that a summary table is a good
suggestion.
Igarashi: How to get feedback from ATSC and HbbTV? Feedback from the industry. The IG may help as liaison point.
ChrisN: That's true.
ChrisN: Next meeting in January, wish you a merry Christmas in advance.
<kaz> [adjourned]