See also: IRC log
<trackbot> Date: 14 May 2013
<scribe> Scribe: joesteele
<scribe> ScribeNick: joesteele
<paulc> John Simmons sent his regrets for today.
http://www.w3.org/2013/04/30-html-media-minutes.html http://www.w3.org/2013/05/07-html-media-minutes.html
<paulc> VER 2 agenda: http://lists.w3.org/Archives/Public/public-html-media/2013May/0082.html
paulc: using later version of the agenda
paulc: 2 items and one
issue
... ACTION 10 was on Adrian
adrianba: there's an action for
everyone to arrive at consensus on model for the session
... have not caught up on the status lately
paulc: bug 19208 is still open?
adrianba: may be
paulc: resolved as a dup of 21855
<paulc> Bug 21855 - Avoid network traffic and duplicate sessions for the same key(s)
<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=21855
paulc: write a proposal for the JS -- Mark did this and the link is in the agenda
<adrianba> ACTION-11?
<trackbot> ACTION-11 -- Mark Watson to write a proposal for the case where the data is not available to the JS -- due 2013-04-16 -- OPEN
<trackbot> http://www.w3.org/html/wg/media/track/actions/11
paulc: believe this is now done?
markw: yes
paulc: marking as closed
ddorwin: showing as closed now
paulc: this is re: moving the ClearKey spec into a separate docs
<paulc> https://www.w3.org/html/wg/media/track/issues/1
paulc: updated a couple of the
sub agenda items based on Aarons status report
... Aaron has updated the editors draft which is in the
agenda
... sent a message giving the update information
... Aaron do you want to add?
acolwell: no - just working on editorial changes
<paulc> Aarron's update on MSE: http://lists.w3.org/Archives/Public/public-html-media/2013May/0075.html
acolwell: will provide some additional text this week
paulc: any comments on
this?
... assume that only outstanding bug it the splicing bug?
<paulc> Bug 21431 - Specify splicing behavior for text tracks
<paulc> https://www.w3.org/Bugs/Public/show_bug.cgi?id=21431
paulc: so you will impleent what is in comment #12?
<paulc> Planning to implement: https://www.w3.org/Bugs/Public/show_bug.cgi?id=21431#c12
jdsmith: at the F2F talking about
video quality we settled returning dropped frames as the
indicator of quality
... it is actually difficult to measure dropped frames
... more accurate for us to measure rendered frames
<adrianba> https://www.w3.org/Bugs/Public/show_bug.cgi?id=20760
jdsmith: original proposal was to
return average frame rate of rendered frames
... returning dropped frames is problematic in our
implementation
paulc: bug number?
<paulc> Current status of 20760 is RESOLVED FIXED
acolwell: question is that we should have the total number and rendered frames, so should calc difference
jdsmith: we have approximate average frame rate so we can approximate
<paulc> [Paul apologizes for his rough cough if it is audible]
acolwell: this should be accurate?
paulc: are you asking to reconsider?
jdsmith: yes -- would prefer to return the data points and let the app figure it out
paulc: would prefer you reopen with explanation, possibly with revised text
jdsmith: ok
acolwell: not clear what the interval is that the frame rate is being measured on -- wary of that metric
markw: re: dropped frames should
be simple as possible for the user to understand
... don't want something simple for us but harder for
users?
... approximation is fine for this purpose
pal: wanted to follow up on the
issue of supporting multiple frame rates
... is this really a requirement?
acolwell: yes
pal: so why not limit every buffer to a single framerate?
acolwell: we don't guarantee a seamless splice between buffers
paulc: do we have a separate bug for this question?
acolwell: no - this discussion came up during time splice accuracy discussion
<markw> In H.264/ISO media files at least there is no such thing as frame rate. Each sample has a timestamp, that is all
paulc: if this is orthogonal -
having a separate bug with a clear disposition would be a good
paper trail
... leave it to others to decide
acolwell: WebM also
paulc: Jerry you will take the action to reopen as necessary
cyril: question about the text track splicing
<paulc> Bug 21431 - Specify splicing behavior for text tracks
cyril: have not read carefully,
but was something said about text tracks having variable frame
rates?
... may not know the duration of the cue
... until the next track comes in
... might have some impact on the management of the cues
acolwell: we are assuming we know
the duration of cues now
... may be a requirement we need to state -- need text track
experts to chime in
cyril: for example video
survellance vidoes may not know the frame rate until the vides
come in
... may extend the duration of the previous sample
acolwell: is this a common use
case we need to solve now? not all MPEG-4 file supported
now
... can file a bug to discuss more
cyril: we can resolve later, but should recognize the issues
acolwell: some discussion has been around defining simple behavior and adding more complex logic later to describe the outlier cases
cyril: I will open a bug
BobLund: comment on the idea of a
cue with unknown length
... not really unknown from a media buffer perspective
... it will have an end, but player may not know the end
... HTML5 is clear on what should happen with the rendering of
text tracks
pal: confirm current thoughts on
behavior
... for purposes of MSE, in the algorithm frames are replaced
by cues
acolwell: non-overlapping
cues
... lots of nastiness when overlapping cues are allowed
paulc: any other bugs for MSE we should discuss?
cyril: have seen in the latest
spec we say
... the MOOV is not allowed in a media segment
... will this trigger a decode error when encountered?
... spec says what is conformant but not non-conformant
acolwell: let me look at the spec
acolwell: look at step 2 of the parsing loop
<paulc> Quote: 2.If the input buffer starts with bytes that violate the byte stream format specifications, then run the end of stream algorithm with the error parameter set to "decode" and abort this algorithm.
acolwell: this shows the signal of a decode error
cyril: when you have a MUST and it is not fulfilled then it is a violation
acolwell: yes
... if you have some text that would make it clearer please
suggest it
cyril: just in a different location, but I understand now
paulc: cross-references in the
spec to make it clearer are useful
... should be useful for 3rd parties who are not in these
discussions
cyril: so maybe a cross-ref to the byte stream specification would help
acolwell: add a normative note
paulc: this will close Wed May
22nd -- this email went out a couple of weeks ago
... we must know what bugs to process prior to Last Call
cyril: if we want bugs resolved before must be filed by then?
paulc: no -- any bugs filed
before that date will be resolved before Last Call
... otherwise it prevents us from going into Last Call
... because we are not at 0 bugs
rrsagent: generate minutes
paulc: this lets us identify the
bugs that must really be addressed by Last Call
... moving on to EME?
cyril: what is the status of the primer?
paulc: did a call for volunteers -- have not received any volunteers as yet
<paulc> Call for volunteers: http://lists.w3.org/Archives/Public/public-html-admin/2013May/0002.html
cyril: might want to volunteer
paulc: might want to have a
conversation with the chairs to confirm what is wanted
... get some context on previous primers
http://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/encrypted-media.html
paulc: David want to make any comments?
ddorwin: no -- sent an email
<paulc> https://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/encrypted-media.html
<paulc> FPWD: http://www.w3.org/TR/2013/WD-encrypted-media-20130510/
<ddorwin> Also, http://www.w3.org/TR/encrypted-media/
paulc: need to update the copyright to match the editors draft
Topic Outstanding Bugs
paulc: 30 of them
<paulc> http://tinyurl.com/7tfambo
paulc: there are is an active email thread on ACTION-11 -- should we spend time on that? or avoid it?
<paulc> http://lists.w3.org/Archives/Public/public-html-media/2013May/0068.html
<markw_> I think it makes sense to talk about the ACTION-11 item
ddorwin: marks email since there has been discussion
paulc: intro to ACTION-11?
markw: proposal was to define
what might happen if CDM data is not available to the JS
apis
... we know there will be CDMs that takes advantage of HW and
data will not be available
... may be cases where it will be available
... need to define behavior when the data is not
available
... two cases - audio and video
... Canvas could be used to access video data with getImageData
to get raw YUV or RGBa data from Canvas
... with audio there is a Media Source Element source
mode
... can do the processing for the audio node
... get back the raw PCM bytes
... could have the original APIs behave as if there was no
media -- probably most likely to be implemented
... drawImage would do nothing, Media Element source mode would
act as if there is no audio
... could image another scenario where they work but just not
for the EME data
<pal> Q: shouldn't the JS application be able to inform the user that video/audio is not available because it is protected?
markw: would be much more
complicated
... maybe we should not exclude this possibility
... maybe we just need to document this behavior?
adrianba: since we won't be able
to definitely describe the behavior for all possible APIs now
and in the future for EME
... we should make this informative following the principle
Mark outlined
... would act as if no data was available
... maybe we can use the Canvas and audio as examples
... let APIs define there own behavior based on this
principle
<markw_> What adrian says makes sense to me
<ddorwin> +1
markw: that is question about the
failure mode
... that would allow the JS to respond differently
<adrianba> You can detect in JS that you're using EME since you have to do something explicit to use it.
markw: something the owners of
both APIS to specify
... app should know if it is dealing with encrypted media
agree with the proposal -- however could be an issue with when some streams are encrypted and others are not, for example ads.
<adrianba> i think we can wait to see if apps run into problems with not knowing whether failure was because of EME or otherwise before engineering a solution to what seems to me to be a corner case
pal: to marks comment - the existnece of EME does not necessairly imply this, seems to be a reluctance to directly indicate this
markw: the way to indicate if it is to be indicated it specific to the APIs (Canvas, audio)
pal: the Canvas element has errors, conceivably we could file a bug that another error is needed e.g. CANNOT_COPY
markw: could be fine to file a bug, up to them whether to expose this
pal: more information better for the JS app
adrianba: echo what Mark said,
hard to enumerate all the places where this data might be
consumed.
... this seems like an edge case as to why the data was
encrypted
... unlikely that an app will have something the user can
correct to handle this
... if that emerges we can solve the problem then
rrsagent: generate minutes
paulc: what do we need to do to
decrease the bug count?
... do we need to nominate a specific list of bugs?
adrianba: bugs are waiting for
feedback -- does not need to be in this meeting
... half of the bugs have proposed solutions
... should not be too difficult but folks need to reply to
them
<ddorwin> Most recently updated bugs: https://www.w3.org/Bugs/Public/buglist.cgi?bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&columnlist=short_desc%2Cassigned_to%2Cpriority%2Cbug_status%2Cresolution%2Ctarget_milestone%2Cchangeddate&component=Encrypted%20Media%20Extensions&product=HTML%20WG&query_format=advanced&list_id=11029
adrianba: most recent bugs would
be a good target
... could have a conversation then
rrsagent: generate minutes
paulc: you are saying we need
folks input before discussing in next weeks meeting
... could be more aggressive in proposing changes to force
folks forward
<ddorwin> Previous email listing of bugs to discuss: http://lists.w3.org/Archives/Public/public-html-media/2013May/0004.html
paulc: resolving bugs as
NEEDS_INFO
... nearly out of time -- please suggest a list of bugs and
people whose input is needed
<ddorwin> New bug: https://www.w3.org/Bugs/Public/show_bug.cgi?id=21977
paulc: will have a mtg next week starting with EME and could start assigning folks to make progress
adrianba: filed a new bug about
swapping parameters
... people should take a look
<ddorwin> https://www.w3.org/Bugs/Public/show_bug.cgi?id=21977 - Swap isTypeSupported() parameter order so keySystem is first
adrianba: link is pasted above
paulc: done for today
rrsagent: generate minutes
paulc: propose focusing on EME next week and MSE after
rrsagent: generate minutes
paulc: done for today
rrsagent: generate minutes
rrsagent: generate minutes
rrsagent: generate minutes
rrsagent: generate minutes
rrsagent: generate minutes
rrsagent: generate minutes
rrsagent: generate minutes
rrsagent: generate minutes
rrsagent: generate minutes
This is scribe.perl Revision: 1.138 of Date: 2013-04-25 13:59:11 Check for newer version at http://dev.w3.org/cvsweb/~checkout~/2002/scribe/ Guessing input format: RRSAgent_Text_Format (score 1.00) Succeeded: s/dup of 28155/dup of 21855/ Succeeded: s/jdsmitth:/jdsmith:/ Succeeded: s/queue/cue/ Succeeded: s/queues/cues/ Succeeded: s/byte range/byte stream/ Succeeded: s/pal: what is/cyril: what is/ Succeeded: s/pal: if we want/cyril: if we want/ Succeeded: s/drawIimage/drawImage/ Succeeded: s/makrs/marks/ Succeeded: s/whether t /whether to / Succeeded: s/jdsmitth: yes -- /jdsmith: yes -- / Succeeded: s/ervye/every/ Succeeded: s/seemless/seamless/ Succeeded: s/duration of the queue/duration of the cue/ Succeeded: s/end player/end, but player/ Succeeded: s/partys/parties/ Found Scribe: joesteele Inferring ScribeNick: joesteele Found ScribeNick: joesteele Default Present: +1.831.457.aaaa, Michael_Thornburgh, paulc, +33.1.45.81.aabb, Cyril, Aaron_Colwell, joesteele, Bin_Hu, ddorwin, glenn, markw, adrianba, pal, [Microsoft], BobLunbd, +1.760.591.aacc, pladd Present: Bin_Hu BobLund Cyril Michael_Thornburgh acolwell adrianba ddorwin glenn jdsmith joesteele markw pal paulc pladd Agenda: http://lists.w3.org/Archives/Public/public-html-media/2013May/0082.html Found Date: 14 May 2013 Guessing minutes URL: http://www.w3.org/2013/05/14-html-media-minutes.html People with action items:[End of scribe.perl diagnostic output]