While in the foreground, an application has full access to the SHAPE hardware. When that application is pushed to the background—pinned, picture-in-picture, or other scenarios—it relinquishes hardware control. By default, its hardware state is suspended, and resumes when the title returns to the foreground. This also is true for Exclusive Resource Applications [ERAs] where the software graph is suspended.
A title may optionally choose to tear down its audio graph and reconstruct it upon resume. Some titles, particularly Shared Resource Applications [SRAs] that play background music such as streaming radio, may choose to have some aspects of audio continue to play even while paused. For these scenarios, titles should closely evaluate whether to attempt a seamless transition from hardware to software rendering, or to always play audio intended for background playback via a software-only pipeline. This has implications for compression formats and CPU costs. XMA-compressed assets, for example, require the use of SHAPE hardware, and thus will not be decodable for a background application.
