Systems and methods for synchronizing operations among a plurality of independently clocked digital data processing devices without a voltage controlled crystal oscillator

• US 8,370,678 B2
• Filed: 08/05/2011
• Issued: 02/05/2013
• Est. Priority Date: 07/28/2003
• Status: Expired due to Term

• Current Assignee: Sonos, Inc.
• Original Assignee: Sonos, Inc.
• Inventors: Millington, Nicholas A. J., Ericson, Michael
• Primary Examiner(s): TRAN, VINCENT HUY
• Application Number:
  US13/204,511
• Publication Number:
  US 20120029671A1
• Time in Patent Office: 550 Days
• Field of Search: 713/500, 713/503, 709/205, 709/248
• US Class Current: 713/500
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G06F 1/00 Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00 architectures of general purpose stored program computers G06F15/76
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: G06F 16/2322 using timestamps
• CPC Class Codes: G06F 16/60 of audio data
• CPC Class Codes: G06F 16/63 Querying
• CPC Class Codes: G06F 16/635 Filtering based on additional data, e.g. user or group profiles
• CPC Class Codes: G06F 16/638 Presentation of query results
• CPC Class Codes: G06F 16/639 using playlists
• CPC Class Codes: G06F 16/68 Retrieval characterised by using metadata, e.g. metadata not derived from the content or metadata generated manually
• 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: G06F 3/048 Interaction techniques based on graphical user interfaces [GUI]
• CPC Class Codes: G06F 3/0482 Interaction with lists of selectable items, e.g. menus
• CPC Class Codes: G06F 3/0484 for the control of specific functions or operations, e.g. selecting or manipulating an object, an image or a displayed text element, setting a parameter value or selecting a range
• CPC Class Codes: G06F 3/04842 Selection of displayed objects or displayed text elements G06F3/0482 takes precedence
• CPC Class Codes: G06F 3/04847 Interaction techniques to control parameter settings, e.g. interaction with sliders or dials
• CPC Class Codes: G06F 3/16 Sound input; Sound output speech processing G10L
• CPC Class Codes: G06F 3/162 Interface to dedicated audio devices, e.g. audio drivers, interface to CODECs
• CPC Class Codes: G06F 3/165 Management of the audio stream, e.g. setting of volume, audio stream path
• CPC Class Codes: G06F 3/167 Audio in a user interface, e.g. using voice commands for navigating, audio feedback
• CPC Class Codes: G11B 20/10527 : Audio or video recording; Data buffering arrangements G11B20/12 - G11B20/18 take precedence
• CPC Class Codes: G11B 2020/10592 : specifically adapted for recording or reproducing multichannel signals
• CPC Class Codes: H03G 3/00 : Gain control in amplifiers or frequency changers
• CPC Class Codes: H03G 3/20 : Automatic control H03G3/005 takes precedence; combined with volume compression or expansion H03G7/00
• CPC Class Codes: H04H 20/103 : Transmitter-side switching
• CPC Class Codes: H04H 20/26 : Arrangements for switching distribution systems
• CPC Class Codes: H04H 2201/20 : digital audio broadcasting [DAB]
• CPC Class Codes: H04J 3/0644 : External master-clock
• CPC Class Codes: H04J 3/0664 : unidirectional timestamps
• CPC Class Codes: H04L 12/2854 : Wide area networks, e.g. public data networks
• CPC Class Codes: H04L 65/1069 : Session establishment or de-establishment
• CPC Class Codes: H04L 65/1094 : Inter-user-equipment sessions transfer or sharing
• CPC Class Codes: H04L 65/60 : Network streaming of media packets
• CPC Class Codes: H04L 65/61 : for supporting one-way streaming services, e.g. Internet radio
• CPC Class Codes: H04L 65/611 : for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04L 65/612 : for unicast
• CPC Class Codes: H04L 65/613 : for the control of the source by the destination control signals issued by the client directed to the server or network components specially adapted for selective content distribution H04N21/637
• CPC Class Codes: H04L 65/75 : Media network packet handling
• CPC Class Codes: H04L 65/80 : Responding to QoS
• CPC Class Codes: H04L 67/1095 : Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/12 : specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 67/55 : Push-based network services
• CPC Class Codes: H04L 69/28 : Timers or timing mechanisms used in protocols
• CPC Class Codes: H04N 21/4307 : Synchronising the rendering of multiple content streams or additional data on devices, e.g. synchronisation of audio on a mobile phone with the video output on the TV screen
• 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 21/43615 : Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals home Audio Video Interoperability [HAVI] data switching networks H04L12/2805
• CPC Class Codes: H04N 5/04 : Synchronising for television systems using pulse code modulation H04N7/56
• CPC Class Codes: H04N 9/7904 : using intermediate digital signal processing
• CPC Class Codes: H04R 2227/003 : Digital PA systems using, e.g. LAN or internet
• CPC Class Codes: H04R 2227/005 : Audio distribution systems for home, i.e. multi-room use
• CPC Class Codes: H04R 27/00 : Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F
• CPC Class Codes: H04R 3/12 : for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04W 56/0015 : one node acting as a reference for the others
• CPC Class Codes: H04W 84/20 : Master-slave selection or change arrangements
• CPC Class Codes: H05K 999/99 : dummy group

Abstract

Exemplary systems and methods include a distribution device that maintains a dock rate and distributes a series of tasks to a group of execution devices. Each task has a plurality of samples per frame associated with a time stamp indicating when the task is to be executed. The execution devices execute the series of tasks at the times indicated and adjust the number of samples per frame in relation to the dock rate maintained by the distribution device.

Claims

1. A digital data processing device comprising:

an interface to receive multimedia information arranged as a plurality of frames, each frame to include a plurality of samples and a time stamp for playback of the samples in a frame;

an information buffer to store the plurality of frames for play back by the digital data processing device,

wherein the digital data processing device is to receive clock information from a source device and determine a time differential value between the received clock information and clock information associated with the digital data processing device, the time differential value to be applied to the time stamp for each of the plurality of frames to store an updated time stamp for each of the plurality of frames in the information buffer; and

an output to play back the samples in a frame from the information buffer according to the updated time stamp for the frame,

wherein the digital data processing device is to adjust, based on a comparison between the updated time stamp for the frame and a predicted time value for play back of the frame, a number of samples per frame that are to be played.

2. The device of claim 1, further comprising a network communications manager to receive the plurality of frames from an audio information source.

3. The device of claim 1, wherein the adjustment of the number of samples per frame is also based on a clock rate of the digital data processing device.

4. The device of claim 1, wherein the digital data processing device is among a group of digital data processing devices and is to be designated as a master execution device configured to control the distribution of information among the group of devices.

5. The device of claim 1, further comprising a user interface module to control the digital data processing device.

6. The device of claim 1, wherein the digital data processing device is configured to enable another device to join a group of digital data processing devices.

7. The device of claim 1, wherein the digital data processing device is to transfer an ability to control the digital data processing device such that another digital data processing device becomes a master execution device.

8. A method for synchronizing audio playback, the method comprising:

receiving, by a playback device, audio information including a plurality of frames from a source device over a network, wherein each frame of the plurality of frames includes audio samples and a time stamp indicating when to play the audio samples of the respective frame;

updating the time stamp for each of the plurality of frames using a time differential value determined between clock information received from the source device and clock information associated with the playback device;

storing the updated time stamp for each of the plurality of frames; and

outputting audio information based on the plurality of frames and associated updated time stamps via the playback device; and

adjusting, based on a comparison between the updated time stamp for the frame and a predicted time value for play back of the frame, a number of samples per frame to be output.

9. The method of claim 8, further comprising enabling the playback device to function as a master execution device configured to control distribution of information among the group of playback devices.

10. The method of claim 9, further comprising enabling an additional playback device to join the group of playback devices.

11. The method of claim 9, wherein audio information is distributed to the group of playback devices using a selected multi-cast transmission methodology.

12. The method of claim 9, further comprising migrating the distribution of audio information from one playback device to another playback device.

13. The method of claim 9, further comprising distributing audio information to a second group of playback devices.

14. The method of claim 8, further comprising generating the predicted time value for the frame using the updated time stamp of a previous frame and a clock rate of the playback device.

15. The method of claim 8, wherein the comparison further comprises comparing whether a difference between the updated time stamp and the predicted time value exceeds a threshold level.

16. A non-transitory computer-readable storage medium including instructions executable by a processor, the instructions, when executed by the processor, performing a method for synchronizing multimedia playback, the method comprising:

receiving, by a playback device, audio information including a plurality of frames

from a source device over a network, wherein each frame of the plurality of frames includes audio samples and a time stamp indicating when to play the audio samples of the respective frame;

updating the time stamp for each of the plurality of frames using a time differential value determined between clock information received from the source device and clock information associated with the playback device;

storing the updated time stamp for each of the plurality of frames;

outputting audio information based on the plurality of frames and associated updated time stamps via the playback device; and

adjusting, based on a comparison between the updated time stamp for the frame and a predicted time value for play back of the frame, a number of samples per frame to be output.

17. The computer-readable storage medium of claim 16, further comprising enabling the playback device to function as a master execution device configured to control distribution of information among the group of playback devices.

18. The computer-readable storage medium of claim 17, further comprising enabling an additional playback device to join the group of playback devices.

19. The computer-readable storage medium of claim 17, further comprising migrating the distribution of multimedia information from one playback device to another playback device.

20. The computer-readable medium of claim 17, wherein the comparison further comprises comparing whether a difference between the updated time stamp and the predicted time value exceeds a threshold level.