W3C

- DRAFT -

Audio Working Group Teleconference

13 Apr 2017

See also: IRC log

Attendees

Present
Joe, Jerry, Paul, Hongchan, Ray, Chris
Regrets
Chair
Joe
Scribe
chrisl

Contents


<rtoyg_m_> present rtoyg_m

<hoch> +present hoch

<rtoyg_m_> +present rtoyg_m

<joe> padenot we see you twice in the WebEx list but neither one is connected

also you can try connecting vie WebRTC in Firefox, now

F2F

CSAIL, 32 Vassar St. room D463 Star

Closest Red line T stop is Kendal MIT

TPAC

PR progress

<joe> https://github.com/WebAudio/web-audio-api/pulls

<scribe> scribenick: chrisl

padenot_: merged a number of PR this week

<joe> https://github.com/WebAudio/web-audio-api/pull/1204

padenot_: lgtm

<ghaudiobot> [web-audio-api] joeberkovitz closed pull request #1204: Disallow empty string as AWP registration key. (gh-pages...1172-no-empty-AWP-names) https://github.com/WebAudio/web-audio-api/pull/1204

joe: merging now

<joe> https://github.com/WebAudio/web-audio-api/pull/1201

<joe> https://github.com/WebAudio/web-audio-api/pull/1200

<ghaudiobot> [web-audio-api] rtoy closed pull request #1201: Fix #1157: Add attributes to Media{Element,Stream}AudioSourceNode (gh-pages...1157-add-attributes-again-for-measn) https://github.com/WebAudio/web-audio-api/pull/1201

<ghaudiobot> [web-audio-api] joeberkovitz closed pull request #1200: Reword treatment of starting time for AudioScheduledSourceNode (gh-pages...915-subsample-accurate-start) https://github.com/WebAudio/web-audio-api/pull/1200

<joe> https://github.com/WebAudio/web-audio-api/pull/1170

<joe> https://github.com/WebAudio/web-audio-api/pull/1065

issues without milestone

<joe> https://github.com/WebAudio/web-audio-api/issues?q=is%3Aopen+is%3Aissue+no%3Amilestone

<joe> https://github.com/WebAudio/web-audio-api/issues/1205

joe: polishing factory methods not very important, lets close it

<joe> https://github.com/WebAudio/web-audio-api/issues/1203

ray: adds nothing, lets remove it

joe: yes, but v1 blocker?

ray: no

<joe> https://github.com/WebAudio/web-audio-api/issues/1202

joe: ok, no way to stop routing audio to the node. How big a use case where a nde switches from serving to not serving the graph

padenot_: have had people requesting this feature, told them it can't be done

joe: why?

padenot_: different playback pipelines, with normal media and a single media element and msc to get decrypted media
... didn't want to have two media elements

joe: sounds like a v.next

<joe> https://github.com/WebAudio/web-audio-api/issues/1199

roy: hongchan reminded me convolver node can be set more than once

hoch: discussed at tpac 3 years ago. cwilso argued against making it unchangeable. Wanted to change impulse response on the fly

padenot_: too late to change now
... on ABSN can't set multiple times but convolver you can
... should initialise it

joe: think this is an error on my part, adding settable once to convolver and didn't do it
... wait, did and it got taken out

ray: bad merge maybe

joe: will look at this and fix it

ray: are we keeping convolver settable multiple times or not?

<joe> https://github.com/WebAudio/web-audio-api/issues/667

<joe> https://github.com/WebAudio/web-audio-api/issues/667#issuecomment-249143280

joe: will look back on what we decided

jerry: we had a PR and it got dropped?

joe: yes. wait, seeing that language in the spec!

<joe> https://github.com/WebAudio/web-audio-api/issues/1194https://github.com/WebAudio/web-audio-api/issues/1194

joe: OK we need to say it is initialised to false. And spec text on convolver stays as it is, settable once

<joe> https://github.com/WebAudio/web-audio-api/issues/1194

hoch: domenic asked me to fix the IDL because handler being part of the node does not make sense, can't handle the event
... anne is asking why it is impossible to be an event target
... want to minimise functionality of descending data
... cause a lot of GC
... discussion ongoing
... anne and domenic are looking more at the whole web platform while we want the audio worklet to work well for its intended purpose

joe: hooking it up to worklet causes this uncertainty

padenot_: web platform implies some things that are complicated and unclear. audio api can't use the normal event loop
... we can do our thing and have patterns that resemble the normal web platform. but not exactly the same
... issue is to not have an event handler

hoch: they want to expose event target on worklet

padenot_: common infrastructure is good but they don't understand at first the specific needs of audio

joe: what about the very last comment on GC?

padenot_: yes, transferable solves this, you bet a pointer instead.
... you get the buffer inside the worklet and treat it how you want. You can let it GC (not smart) or send in back for GC on the main thread

joe: okay, let this active thread continue for a bit

ray: v1 blocker?

padenot_: yes. important to make sure we address our needed use cases and efficiently access large buffers is critical
... worklet has always been a blocker, necessary to resolve, implement and ship for v1
... anne's suggestion might be worth it
... get transferable for free

define a normal event loop, get the buffer before rendering. ordering important

ray: we are implementing now and this changes things a lot

padenot_: pretty lightweight, bu requires some sort of event loop

joe: we should not let other groups uncertainties halt our progress. worry that may be the case here

padenot_: agreed
... need to chat more and explain more

<joe> https://github.com/WebAudio/web-audio-api/issues/1193

hoch: this one is easy, see summary at end of thread

joe: is this a v1 blocker?

hoch: yes

<joe> https://github.com/WebAudio/web-audio-api/issues/1188

chris: suggest closing the 'do nothing' one. not useful

padenot_: was wanting to close it after discussion

joe: lets close

jerry: there are workarounds, this is just for linking different status

padenot_: big audio apps just use agin nodes everywhere

<joe> https://github.com/WebAudio/web-audio-api/issues/1182

ray: can't create a type error in chrome. should be handled at the binding layer, like range errors

padenot_: how do you do that at the binding layer, in IDL? or is it spec text?

ray: not sure
... these are enums except for range error etc which are not the same type
... we already throw range error

padenot_: like range errors, more informative, it is the right type but out of range

ray: will follow up internally

<joe> https://github.com/WebAudio/web-audio-api/issues?q=is%3Aopen+is%3Aissue+label%3A%22V1+Blocker%22+sort%3Acreated-asc

8 open blockers, want to be zero by f2f in June

padenot_: after fixing constructor I can get to the dynamics compressor

chris: lots of little PR should help

padenot_: yes it will be fine

ray: IDL is frozen after the constructor stuff, we can update to latest respec after that and it will fix it

jerry: ordering is similar but not identical. wav format extensible is a very old spec. creates some problems

padenot_: we need to pick something

joe: we did, we picked smpte

jerry: sorting out with media pipeline folks

padenot_: we use smpte in Gecko, not set in stone, was unspecced so we went for that
... remap channels soconsistent across all codecs and containers

joe: next call in 2 weeks

(adjourned)

Summary of Action Items

Summary of Resolutions

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Guessing input format: Irssi_ISO8601_Log_Text_Format (score 1.00)

Present: Joe Jerry Paul Hongchan Ray Chris
Found ScribeNick: chrisl
Inferring Scribes: chrisl
Found Date: 13 Apr 2017
Guessing minutes URL: http://www.w3.org/2017/04/13-audio-minutes.html
People with action items: 

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