Surround sound in automotive audio system

1 . A method of adapting an automotive audio system to support surround sound, the method comprising:

configuring an application program for creation of an audio track object that specifies passthrough mode as a playback mode, wherein the application program is installed to operate under an operating system that is not configured for surround sound;

configuring a framework of the operating system with a bypass past a mixer of the operating system, wherein the bypass allows surround-sound data of the audio track object to bypass the mixer; and

configuring a hardware abstraction layer with a separate channel for the surround-sound data received from the operating system, wherein the hardware abstraction layer processes the surround-sound data before providing the processed surround-sound data to a decoder.

2 . The method of claim 1 , wherein configuring the application program comprises adding support for specifying the passthrough mode as the playback mode.

3 . The method of claim 1 , wherein the application program has a condition for providing surround sound output that the framework of the operating system should support surround sound playback, and wherein configuring the framework with the bypass causes the framework to satisfy the condition.

4 . The method of claim 1 , wherein the separate channel facilitates buffer management.

5 . The method of claim 1 , wherein the separate channel facilitates timestamp calculation.

6 . The method of claim 5 , wherein at least processing of the surround-sound data is performed using a first hardware board, wherein at least decoding is performed using a second hardware board separate from the first hardware board, and wherein the hardware abstraction layer uses the timestamp calculation to provide a frame estimate to the application program.

7 . A method of playing surround sound on an automotive audio system of a vehicle, the method comprising:

creating, using an application program of the automotive audio system, an audio track object that specifies passthrough mode as a playback mode, wherein the application program is installed to operate under an operating system that is not configured for surround sound;

bypassing, in a framework of the operating system, a mixer of the operating system by surround-sound data of the audio track object;

processing the surround-sound data at a hardware abstraction layer of the automotive audio system;

providing the processed surround-sound data to a decoder to generate a decoded surround sound signal; and

providing the decoded surround sound signal to at least one of multiple speakers of the vehicle.

8 . The method of claim 7 , wherein creating the audio track object, bypassing of the mixer, and processing the surround-sound data are performed using a first hardware board, and wherein decoding and providing the decoded surround sound signal are performed using a second hardware board separate from the first hardware board.

9 . The method of claim 7 , wherein the application program has a condition for providing surround sound output that the framework of the operating system should support surround sound playback, and wherein the bypassing of the mixer causes the framework to satisfy the condition.

10 . The method of claim 7 , wherein the processing of the surround-sound data comprises buffer management.

11 . The method of claim 7 , wherein the processing of the surround-sound data comprises timestamp calculation.

12 . The method of claim 11 , wherein at least the processing of the surround-sound data is performed using a first hardware board, and wherein at least decoding is performed using a second hardware board separate from the first hardware board, the method further comprising using the timestamp calculation to provide a frame estimate to the application program.