Increased speed of processing of data received over a communications link

• US 8,589,604 B2
• Filed: 12/17/2012
• Issued: 11/19/2013
• Est. Priority Date: 04/14/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Mora, Matthew Xavier, Warren, Niel D.
• Primary Examiner(s): Tsai, Henry
• Assistant Examiner(s): Sun, Michael
• Application Number:
  US13/717,505
• Publication Number:
  US 20130184842A1
• Time in Patent Office: 337 Days
• Field of Search: None
• US Class Current: 710/52
• CPC Class Codes: G06F 3/162 Interface to dedicated audio devices, e.g. audio drivers, interface to CODECs
• CPC Class Codes: G06F 5/065 Partitioned buffers, e.g. allowing multiple independent queues, bidirectional FIFO's
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 49/9063 Intermediate storage in different physical parts of a node or terminal

Abstract

A method and apparatus for processing data samples utilizes a channel map populated by device descriptor, or by an application program interface. Packet processing code loops through all of the samples contained in a packet while incrementing through a channel map and steering table without having to look up a table to determine in what audio buffer the sample is to be stored or read. Additionally, the present invention utilizes a stride map, so the audio subsystem knows how many samples to skip in order to reach the next sample frame. The present invention can be used for handling received packets as well as forming packets to send over a bus.

Claims

1. A method for providing support for at least one media device driver, the method comprising:

obtaining a channel order and a number of channels to process; and

based at least in part on the obtained channel order and the number of channels to process, determining;

a first element indicating the channel order, the channel order describing an order of packed data channels within frames of data;

a second element indicating at least one parameter, the at least one parameter determining a number of data samples to skip, corresponding to others of the data channels, between sequential data samples of the same data channel; and

a third element indicating one or more start addresses for the data channels.

2. The method of claim 1, wherein the first element, second element, and third element comprise a steering table, stride map, and channel map, respectively.

3. The method of claim 2, wherein the one or more start addresses reside within a sample buffer.

4. The method of claim 1, wherein the one or more start addresses reside within a sample buffer.

5. The method of claim 2, further comprising publishing the determined steering table, stride map, and channel map to the at least on media device driver.

6. The method of claim 5, wherein the act of publishing the steering table, the stride map, and the channel map substantially offloads processing from the at least one media device driver, thereby enhancing its efficiency.

7. The method of claim 1, wherein the channel order and number of channels to process are obtained upon detecting a user selecting a mode of operation for the at least one media device driver.

8. The method of claim 2, wherein the channel map is further configured to accommodate a mismatched sample size or packet size with respect to an application stream size.

9. An apparatus for processing frames of data comprising a plurality of data channels, each data channel comprising a plurality of sequential data samples, the data channels disposed within the frames of data, the apparatus comprising:

a first interface configured to receive packetized data comprising at least frames of data;

a sample buffer configured for of storage of one or more of the frames of data; and

a computer readable apparatus comprising media non-transitory storage comprising a plurality of instructions, the plurality of instructions which are configured to, when executed, cause the apparatus to;

receive information enabling unpacking of the frames of data;

read one or more of the frames of data in the sample buffer;

unpack the read one or more frames of data into a first set of data channels based at least in part on the information; and

publish a second set of data channels to at least one audio device driver.

10. The apparatus of claim 9, wherein the at least one audio device driver processes only the published second set of data channels.

11. The apparatus of claim 9, wherein the packetized data further comprises a device descriptor;

and

wherein the information enabling unpacking of the frames is based at least in part on the device descriptor.

12. The apparatus of claim 9, wherein the information enabling unpacking of the frames comprises information received via an application programming interface (API).

13. The apparatus of claim 9, wherein each data channel comprises one or more Common Isochronous Packets (CIP).

14. The apparatus of claim 9, wherein the first interface comprises an interface to an IEEE Std. 1394-compliant bus.

15. The apparatus of claim 9, wherein the first interface comprises an interface to a-Universal Serial Bus (USB)-compliant bus.

16. The apparatus of claim 9, further comprising a second interface configured to transmit the second set of data channels to at least one second device.

17. The apparatus of claim 16, wherein the at least one audio device driver is resident within the at least one other second device.

18. The apparatus of claim 9, wherein the at least one audio device driver is local to the apparatus.

19. A method for processing data samples for at least one media device driver, the method comprising:

obtaining information enabling unpacking of frames of data stored in a buffer;

reading one or more of the frames of data in the buffer;

unpacking the read one or more frames into a first set of data channels based at least in part on the obtained information;

packing a second set of data channels from the first set of data channels based at least in part on the obtained information; and

publishing the second set of data channels to at least one media device driver;

wherein the at least one media device driver processes only the published second set of data channels.

20. The method of claim 19, wherein the information enabling unpacking of frames of data comprises a device descriptor associated with the frames of data stored in the buffer.

21. The method of claim 19, wherein the information enabling unpacking of frames of data is received from a process executing on an audio subsystem via an application programming interface (API).

22. The method of claim 21, wherein the information enabling unpacking of frames of data is generated when a change of a configuration of the audio subsystem is detected.

23. The method of claim 22, wherein the detected change of the configuration comprises a change in a number of audio channels operating in the audio subsystem.

24. The method of claim 19, wherein the publishing of the second set of data channels offloads processing from the at least one media device driver.