DLL stream handlers must supply an interface to communicate with the Sync/Stream Manager. This interface, called the stream handler command (SHC) interface, exports stream handler commands (SHCs) for use by the Sync/Stream Manager to set up and control data streams. These SHCs are accessible through a single entry point, SHCEntryPoint.
In addition, device driver stream handlers receive commands from the Sync/Stream Manager to initialize and perform streaming functions. These stream handler commands (SHCs) are also accessible through SHCEntryPoint. The main routine is an IDC interface with the Sync/Stream Manager Device Driver. The SSM calls the device driver stream handler by issuing stream programming interface (SPI) functions such as SpiCreateStream, SpiStartStream, and SpiStopStream.