598792 - Window 7 Default 'Audio Ducking' behavior causes Flash based communications applications to lose 80% of their volume

Status: RESOLVED WONTFIX

(Core Graveyard :: Plug-ins, defect)

Description

[Sidd Gupta]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.10) Gecko/20100914 Firefox/3.6.10
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.10) Gecko/20100914 Firefox/3.6.10

* We are a VOIP provider that offers a pure flash based client for two way and multi party calling.
* In Windows 7, the audio subsystem has a new type of behavior called 'ducking'. It is meant to lower system and other 'non communication' sounds whenever the OS detects that the user might be engaging in communication. 
* The default behavior is for all 'non communication' sounds to be 'ducked' (volume reduced) by 80% for the duration of the call.
* It appears that the OS considers the plugin-container.exe (which is running the flash player that our system uses for both audio capture and render) to be 'duckable' resulting in a loss of audio volume and quality for our end users.
* This problem can be remedied if the plugin-container simply registers for  so called 'ducking notifications' and/or expressly disables this behavior for itself.
* Here is a link to the msdn tech note describing how to do this:
http://msdn.microsoft.com/en-us/library/dd940391%28VS.85%29.aspx

Reproducible: Always

Steps to Reproduce:
1. Sign up for apps.facebook.com/vivoxvoice
2. Invite one of your friends to a call
3. Click the flash permissions dialog on windows 7. Notice that the render volume (your friend's voice) is drastically reduced if you are using FF 3.6.4 or above


Expected Results:  
* If the plugin container can disable the (windows 7) default ducking behavior, no drop in render volume should be experienced.

Comment 1

[Benjamin Smedberg]

I think we *want* ducking by default: I bet that most flash audio is not communication.

Comment 2

[Sidd Gupta]

(In reply to comment #1)
> I think we *want* ducking by default: I bet that most flash audio is not
> communication.

Hi Benjamin,

While I don't disagree, the fact is that this is new default behavior (for windows) *and* IE, the native windows browser *does not* automatically duck it's audio (I wonder why ? :)

If there are some misgivings about modifying the default behavior, there should be some way for web applications to programmatically control the behavior of the plugin container with respect to the windows 7 audio ducking.

Regards,

Sidd

Comment 3

[Boris Zbarsky [:bzbarsky]]

You'd win that bet, but is there any sane way to let communication apps opt in or something?  I guess not without all the crappy ads opting in too....

Comment 4

[Sidd Gupta]

(In reply to comment #1)
> I think we *want* ducking by default: I bet that most flash audio is not
> communication.

Hi Benjamin,

While I don't disagree, the fact is that this is new default behavior (for windows) *and* IE, the native windows browser *does not* automatically duck it's audio (I wonder why ? :)

If there are some misgivings about modifying the default behavior, there should be some way for web applications to programmatically control the behavior of the plugin container with respect to the windows 7 audio ducking.

Regards,

Sidd

Comment 5

[Daniel Veditz [:dveditz]]

If it's not blocking the un-released next version then it can't be blocking the security updates. But if it's fixed on trunk we'll look at the patch for branches.

CC'ing Cww -- support probably needs to be aware of this Windows 7 behavior in case they get questions.

Comment 6

[James May [:fowl2]]

So Windows is detecting that a communication program is operating, and then ducking it?

Comment 7

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

Is there any way to automatically figure out the right thing to do here?  It doesn't seem like it ...

Comment 8

[(not currently active) Ted Mielczarek]

Short of providing a DOM API for webapps to indicate that they are a communications app and should not have this behavior applied, I don't know of any way we'd do it.

Comment 9

[Benjamin Smedberg]

We are not going to fix this for Flash.  If this affects webrtc communications, we should make sure that it is on file and fixed.