Systems and methods for synchronizing operations among a plurality of independently clocked digital data processing devices that independently source digital data

• US 8,086,752 B2
• Filed: 10/02/2007
• Issued: 12/27/2011
• Est. Priority Date: 11/22/2006
• Status: Expired due to Fees

• Current Assignee: Sonos, Inc.
• Original Assignee: Sonos, Inc.
• Inventors: Millington, Nicholas A. J.
• Primary Examiner(s): Chan, Wing
• Assistant Examiner(s): KATSIKIS, KOSTAS J
• Application Number:
  US11/906,702
• Publication Number:
  US 20080120429A1
• Time in Patent Office: 1,547 Days
• Field of Search: 709/231, 709/248, 370/503
• US Class Current: 709/231
• CPC Class Codes: G06F 16/60 of audio data
• CPC Class Codes: G06F 17/00 Digital computing or data processing equipment or methods, specially adapted for specific functions information retrieval, database structures or file system structures therefor G06F16/00
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/43076 of the same content streams on multiple devices, e.g. when family members are watching the same movie on different devices
• CPC Class Codes: H04N 21/6332 directed to client
• CPC Class Codes: H04N 21/654 Transmission by server directed to the client
• CPC Class Codes: H04N 21/6547 comprising parameters, e.g. for client setup
• CPC Class Codes: H04N 21/8106 involving special audio data, e.g. different tracks for different languages

Abstract

In a system for distributing data, distribution device is configured to distribute timestamp, offset and source location information for a digital data stream to an execution device, and the execution device is configured to seek digital data corresponding to the received information. The execution device is further configured to execute the digital data relative to a clock rate maintained by the distribution device. Related methods include receiving timestamp, offset and source location information for the digital data stream and seeking digital data corresponding to the received offset and source location information.

Claims

1. A system for distributing digital data, the system comprising:

a digital data processing device configured to add header information to a stream that includes digital data, process the stream to render the digital data unusable by an execution device, wherein rendering the digital data unusable by an execution device comprises at least one of blanking out and truncating the digital data, and distribute the stream, wherein the header information includes timestamp information, offset information, and source location information for the stream; and

an execution device configured to receive the processed stream from the digital data processing device, wherein the processed stream includes the digital data rendered unusable by the digital data processing device, locate a source of the digital data other than the digital data processing device based on the source location information, seek an offset in the digital data based on the offset information, and retrieve the digital data at the offset from the source other than the digital data processing device.

2. The system of claim 1, wherein the execution device is further configured to execute the digital data relative to a clock rate maintained by the digital data processing device.

3. The system of claim 2, wherein the execution device is further configured to adjust a number of samples per frame of the digital data in relation to the clock rate maintained by the digital data processing device.

4. The system of claim 2, wherein the execution device is further configured to adjust a clock rate of the execution device in relation to the clock rate maintained by the digital data processing device.

5. The system of claim 1, wherein the digital data processing device is further configured to adjust the timestamp information relative to a clock rate maintained by the execution device.

6. The system of claim 5, wherein the execution device is further configured to execute the digital data relative to a clock rate maintained by the execution device.

7. The system of claim 1, wherein the execution device is further configured to execute the digital data relative to an audio information buffer maintained by the digital data processing device.

8. The system of claim 7, wherein the execution device is further configured to adjust a number of samples per frame of the digital data in relation to the rate of change in the audio information buffer maintained by the digital data processing device.

9. The system of claim 7, wherein the execution device is further configured to adjust a clock rate of the execution device in relation to the rate of change in the audio information buffer maintained by the digital data processing device.

10. The system of claim 1, wherein the digital data processing device is further configured to adjust the timestamp information relative to a rate of change in audio information buffer maintained by the execution device.

11. The system of claim 10, wherein the execution device is further configured to execute the digital data relative to the rate of change in the audio information buffer maintained by the execution device.

12. The system of claim 1, further comprising a plurality of execution devices wherein one of the execution devices is a master execution device configured to control the distribution of the offset information and source location information by the digital data processing device.

13. The system of claim 12, further comprising a user interface module configured to control the master execution device.

14. The system of claim 12, wherein the master execution device is configured to enable another execution device to join the plurality of execution devices.

15. The system of claim 1, wherein the offset information and source location information is distributed to the execution device using a selected multi-cast transmission methodology.

16. The system of claim 12, wherein the master execution device is configured to transfer the ability to control the digital data processing device such that another execution device becomes the new master execution device.

17. The system of claim 16, wherein the ability to control the digital data processing device includes the ability to transfer the digital data processing device function between various execution devices in the system.

18. A method for distributing digital data, the method comprising:

receiving a stream processed by a digital data processing device to add header information to the stream and render digital data included in the stream unusable by an execution device, wherein rendering the digital data unusable by an execution device comprises at least one of blanking out and truncating the digital data, wherein the header information includes timestamp information, offset information, and source location information for the stream;

locating a source of the digital data other than the digital data processing device based on the source location information;

seeking an offset in the digital data based on the offset information; and

retrieving the digital data at the offset from the source other than the digital data processing device.

19. The method of claim 18, further comprising executing the digital data relative to a clock rate maintained by the digital data processing device.

20. The method of claim 18, further comprising adjusting a number of samples per frame of the digital data in relation to the clock rate maintained by the digital data processing device.

21. The method of claim 18, further comprising adjusting a clock rate of an execution device in relation to the clock rate maintained by the digital data processing device.

22. The method of claim 18, further comprising adjusting the timestamp relative to a clock rate maintained by an execution device.

23. The method of claim 22, further comprising executing the digital data relative to the clock rate maintained by the execution device.

24. The method of claim 19, further comprising substituting a rate of change of an audio information buffer for the clock rate.

25. The method of claim 24, further comprising adjusting a number of samples per frame of the digital data in relation to the rate of change in the audio information buffer maintained by the digital data processing device.

26. The method of claim 24, further comprising adjusting a clock rate of an execution device in relation to the rate of change in the audio information buffer maintained by the digital data processing device.

27. The method of claim 18, further comprising adjusting the timestamp information relative to a rate of change in an audio information buffer maintained by an execution device.

28. The method of claim 27, further comprising executing the retrieved digital data relative to the rate of change in the audio information buffer maintained by the execution device.

29. The method of claim 18, further comprising notifying the digital data processing device via an out-of-band HTTP transaction that an execution device is prepared to initiate execution.