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