Status

Approved

Contributors

• Last modified: June 24, 2015
• Authors: Kyle Huey (Mozilla), Benoit Girard (Mozilla)
• Contributors: Josh Aas (Mozilla)

Use case

The ability to mute/unmute tabs or determine which tabs are playing audio is a commonly requested feature in web browsers. This specification allows browsers to mute/unmute instances of cooperating plugins and determine which instances are playing audio. Browsers can use these APIs to implement per-tab audio control.

Proposed Specification

Determine if an instance is playing audio

NPPVpluginIsPlayingAudio = 4000

This NPPVariable, when set via NPN_SetValue, will signal whether or not an instance is currently playing audio. This is done by assigning a BOOL value to NPN_SetValue's pointer value argument (not by pointing to a BOOL, as one might expect).

Mute/Unmute a plugin instance

NPNVmuteAudioBool = 4000

This NPNVariable, when set via NPP_SetValue, will indicate to a plugin whether or not it should mute audio for an instance. This is done by assigning a BOOL value to NPP_SetValue's pointer value argument (not by pointing to a BOOL, as one might expect).