- From: Chris Rogers <crogers@google.com>
- Date: Tue, 20 Mar 2012 12:11:17 -0700
- To: Jerome Etienne <jerome.etienne@gmail.com>
- Cc: public-audio@w3.org
- Message-ID: <CA+EzO0kkxhrcBjM23j=Q=WSz54MO_6kvW=pU9jX9NzE2A=xq3w@mail.gmail.com>
On Tue, Mar 13, 2012 at 7:00 AM, Jerome Etienne <jerome.etienne@gmail.com>wrote: > Hi, > > While experimenting with webaudio api[1], i hit some issues which > triggered questions. I am new to this mailing list, so im not sure it is > the proper forum. If it isnt, feel free to reroute me :) > > 1. How to handle page visibility ? > When the page isnt visible, what is the recomended behavior ? should i set > the volume to 0 ? something else ? > Currently i do nothing special, but it has glitches. The positional audio > isnt updated. And i hear "clicks" in the audio when the browser is busy on > some other pages (implementation issue related to scheduling?) > Often the expected behavior would be to mute the sound (set gain/volume to 0). But in some use cases, it may be interesting to keep the sound playing, for example if the user would like to continue hearing music while a tab is in the background. > > 2. How to handle 'gimbal lock' with positional audio ? > When the sound is exactly on top of the listener, it is heard as if it was > from the left, then from the right. At first sight, it seems close to a > gimbal lock[2] issue. Is this diagnostic correct ? How to handle this ? > Should i ignore it and say 'well it is rare enougth, nobody will notice' ? > is that an issue in my code or in the browser implementation ? > Interesting question. I would expect the implementatation to handle transitions smoothly. But, I should check the region exactly on top of the listener to see if I can re-create your problems in the WebKit implementation. Perhaps there's a bug, or we're simply not interpolating as well as we could in that area. > > 3. When using audiopannernode, coneOuterAngle seems to be ignored. > Let me explain. When i change .coneInnerAngle and .coneOuterGain, they > have the effect i expect. But no matter which value i put in > .coneOuterAngle, the outter cone seems to be the max possible. According my > understand, there are 3 states. "inside innerCone", "inside outerCone" and > "totally outside". Is that correct ? when the listener is "totally > outside", im under the impression no sound should be heard, correct ? > Are you still having problems here? The three zones you describe correctly, but "totally outside" is not necessarily "no sound" but instead depends on .coneOuterGain. A quick look at the code seems to show it's doing the right thing, but if you are still having the problem then a small code sample would be helpful. > > Lots of questions on various subjects :) Please, let me know what you > think. > > > Jerome > > > [1] https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html > [2] http://en.wikipedia.org/wiki/Gimbal_lock >
Received on Tuesday, 20 March 2012 19:11:49 UTC