Abstract: An audio application programming interface (API) enables an audio processing graph to be modified during processing. If they are received while the audio graph is playing or paused, graph modifying commands may be inserted into either an asynchronous command queue or a deferred command queue. The audio API may also include a clock manager for synchronizing clocks from a number of different connected audio rendering devices, applications, processors, functions, operations, modules, or other resources. The clock manager may provide an interface that enables a number of control groups to be defined. Each such control group may include a master clock, a slave clock, and a control.

Abstract: Automatic protocol migration when upgrading operating systems includes checking, after upgrading at least a portion of an operating system of a host device, whether a new driver supporting enhanced functionality for a portable device is now available, where a driver supporting base functionality would have been previously used for communicating with the portable device. If such a new driver supporting enhanced functionality for the portable device is now available, then the host device installs the new driver supporting enhanced functionality for the portable device.

Abstract: In accordance with certain aspects of the automatic protocol determination for portable devices supporting multiple protocols, a portable device detects which one of the multiple protocols is being used by the host device for subsequent communication with the portable device. This detection is based on the content of a command received from a host device. The detected protocol is then used by the portable device for subsequent communication with the host device. The host device may also send, to the portable device, a notification of which of the multiple protocols is being used by the host device.

Abstract: Safe mode operation for portable devices supporting multiple protocols includes a portable device that supports multiple protocols, such as a base functionality protocol and an enhanced functionality protocol, reporting to a host device that the portable device supports only a single protocol (e.g., the base functionality protocol). This single protocol will be used for subsequent communication between the host device and the portable device. This reporting to the host device that the portable device supports only a single protocol can be triggered, for example, by an appropriate button(s) on the portable device being pressed when the portable device is powered on.

Abstract: A method for converting sample rates includes obtaining coefficients from a sample rate conversion coefficient table. In this method, the table is generated prior to the real-time sample rate conversion using LaGrange Interpolation based on the ratio of the input sample rate to the output sample rate.

Abstract: A digital graphic equalizer uses a predetermined number of equalizing bands each having a different center frequency, and the center frequencies span a predetermined audio bandwidth. For each equalizing band a minimum set of filters is provided. The filters have a predetermined linear uniform spacing between the gain of successive filters.