General purpose data container method and apparatus for implementing AV/C descriptors

• US 7,574,650 B1
• Filed: 09/12/2003
• Issued: 08/11/2009
• Est. Priority Date: 10/28/1999
• Status: Expired due to Fees

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Staats, Erik P.
• Primary Examiner(s): Paula; Cesar B
• Application Number:
  US10/660,945
• Time in Patent Office: 2,160 Days
• Field of Search: 715/500, 715/500.1, 715/501.1, 715527-528, 715/716, 715727-728, 715/9, 715/978, 715200-203, 715/205, 715/248, 715/250
• US Class Current: 715/201
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation

Abstract

Disclosed herein is a data management system for AV/C descriptor data. The system includes a data container hierarchical structure. The system also includes a methodology for compiling data from the containers into a read buffer upon receipt of a request from a requester. The data presented to the requester will preferably be in a format that may be understood by other device requesters that may or may not be utilizing this same container system.

Claims

1. A storage device comprising a computer readable medium comprising instructions which, when executed on a computer system:

read a contiguous media control descriptor data stream comprising a first format;

compile a plurality of containers containing said media control descriptor data from said stream, said plurality of containers comprising a second format;

arrange said containers into a logical hierarchy;

present the hierarchy to a device requesting data from said stream; and

compile said plurality of containers in said second format back into said first format;

wherein said plurality of containers are individually accessible by a device requesting data thereby allowing access to an individual container without affecting the access to any other container containing data from said stream; and

wherein, absent said plurality of containers, said media control descriptor data stream would have to be accessed as a whole.

2. The storage device of claim 1, wherein said media control descriptor data is compliant with revision 3.0 of the AV/C Digital Interface Command Set General Specification.

3. The storage device of claim 1, wherein at least a portion of said contiguous media control descriptor data from said stream is accessible via multiple memory addresses.

4. The storage device of claim 3, wherein at least one of said plurality of containers comprises information for access to each container in said plurality of containers.

5. The storage device of claim 4, further comprising at least one instruction which when executed registers one or more fields of said contiguous media control descriptor data from said stream within each of said plurality of containers.

6. The storage device of claim 5, further comprising at least one instruction which when executed associates addresses with each of said fields sequentially enumerated within each of said containers.

7. The storage device of claim 6, further comprising at least one instruction which when executed maps said fields to a prescribed field list.

8. The storage device of claim 7, further comprising at least one instruction which when executed reads data from any field within any container without affecting the access to any other container.

9. The storage device of claim 8, wherein said plurality of containers comprise in combination an audio visual control general object list descriptor.

10. A storage device comprising a computer readable medium comprising instructions which, when executed on a computer system:

read media control descriptor data comprising a first format;

compile a plurality of containers containing said media control descriptor data, said plurality of containers comprising a second format;

arrange said containers into a logical hierarchy;

present the hierarchy to a device requesting said media control descriptor data; and

compile said plurality of containers in said second format back into said first format;

wherein said plurality of containers are individually accessible by a device requesting data thereby allowing access to an individual container without affecting the access to any other container containing said descriptor data; and

wherein, absent said plurality of containers, said media control descriptor data would have to be accessed as a whole.

11. The storage device of claim 10, wherein said media control descriptor data is compliant with revision 3.0 of the AV/C Digital Interface Command Set General Specification.

12. The storage device of claim 10, wherein at least one of said plurality of containers comprises a direct representation of a data field in an audio visual control descriptor.

13. The storage device of claim 12, wherein at least one of said plurality of containers comprises an alternate representation of a second audio visual control descriptor field.

14. The storage device of claim 13, wherein at least one of said plurality of containers comprises information on how to produce a third audio visual control descriptor field.

15. The storage device of claim 10, wherein at least a portion of said media control descriptor data is adapted to be accessed when its parent is accessed.

16. The storage device of claim 10, wherein said plurality of containers each comprise one or more data fields of an audio visual control descriptor data, wherein a first data field in a first one of said plurality of containers comprises a static data field and a second data field in a second one of said plurality of containers comprises a dynamic data field.

17. A storage device comprising a computer readable medium comprising instructions which, when executed on a computer system:

read media control descriptor data rendered in at least a first format;

generate a plurality of containers of a second format containing said media control descriptor data, and arrange said containers into a hierarchy;

present at least a portion of the hierarchy to a device requesting said media control descriptor data; and

convert said plurality of containers in said second format back into said first format;

wherein said plurality of containers are individually accessible by said requesting device, thereby allowing access to individual ones of said containers without affecting the access to any other of said containers; and

wherein, absent said plurality of containers, said media control descriptor data could not be individually accessed.

18. The storage device of claim 17, wherein said media control descriptor data is compliant with revision 3.0 of the AV/C Digital Interface Command Set General Specification.

19. The storage device of claim 17, wherein said plurality of containers each comprise one or more data fields of an audio visual control descriptor data, wherein a first data field in a first one of said plurality of containers comprises a static data field and a second data field in a second one of said plurality of containers comprises a dynamic data field.

20. The storage device of claim 19, wherein said dynamic data field is constructed in response to a request from the device requesting data.

21. The storage device of claim 20, further comprising instructions which when executed:

identify a top level data container containing audio visual control descriptor data;

initialize one or more compilation attributes;

read the container data; and

copy said read container data into a readable storage area.

22. The storage device of claim 20, further comprising instructions which when executed:

access any field within any container independently of any other container; and

write data to any dynamic data field without affecting the access to any other container.

23. The storage device of claim 20, further comprising instructions which, when executed on a computer system:

access said static data field in said first container without affecting access to said dynamic data field in said second container.

24. The storage device of claim 17, wherein said media control descriptor data stream comprises audio visual control descriptor data, said audio visual control descriptor comprising a length field indicating a length of said audio visual control descriptor.

25. The storage device of claim 24, further comprising instructions which, when executed:

establish a read buffer in a memory space and set the read buffer offset to zero;

establish a received address request as a starting address; and

establish a received read length request as a length sought.