Wwise SDK 2018.1.11
On many consoles it is possible to replace the game music with the user's own music from his personal library. This feature is almost automatic in Wwise. However, there are some differences in implementation and behavior for some platforms.
On all platforms, the initial setup is the same: the sound designer must tag the busses that will be muted when the user starts his music. This is done with the "Mute for Background Music" check box. On the code side, some additional details are needed depending on the platform.
Make sure to fill the jNativeActivity member of the AkPlatformInitSettings. The Mute/Unmute action will occur only when the user switches from the music player app to the game. This means that there is no "Unmute" if the user music finishes by itself.
If the AudioSession flag "MixOther" is set in the sound engine initialization settings, the Mute/Unmute action will occur only when the user switches from the music player app to the game. This means that there is no "Unmute" if the user music finishes by itself. On iOS8 and later, if the AVAudioSessionCategoryAmbient category is used, muting and unmuting of the game music will occur for all application audio interruptions.
Some platforms have a DVR function that allows the gamer to record his gameplay and publish it. This raises a few legal issues regarding the copyrighted music that might be part of the game audio, or user-replaceable music. While the game studio have the rights to use the music in their game, the end-user doesn't have the rights to distribute it in any form. Thus the platform requirements usually state that user background music should not be recorded.
The cost-effective solution (CPU-wise) for this problem is to mix the music separately from the rest of the game. This is done using the Secondary Output feature.
In the authoring tool, you will need to route your music objects to a separate master Audio Bus than the default or primary one. In most projects, this means creating a brand new master Audio Bus (right click on the Master Mixer Hierarchy's Work Unit and select Add > Child). By default, all busses are routed to the System output. Change the Audio Device ShareSet to point to the DVR output.
Don't forget that not all platforms support a DVR. You will need to Unlink the Audio Device property to point to the System output for those platforms. Alternatively, unlink the Output Bus property of the music objects.
The DVR output must be added manually, if used in the game. This is done with
AK::SoundEngine::AddOutput(), passing the Audio Device ShareSet name (or ID) along with other parameters in
Note: Important Note for PS4 You must add the secondary output with
For an example, refer to <Wwise installation path>/SDK/samples/IntegrationDemo/DemoPages/DemoBGM.cpp.