SYSTEM AND METHOD FOR SYNCHRONIZING OPERATIONS AMONG A PLURALITY OF INDEPENDENTLY CLOCKED DIGITAL DATA PROCESSING DEVICES

• US 20130254419A1
• Filed: 05/15/2013
• Published: 09/26/2013
• Est. Priority Date: 07/28/2003
• Status: Active Grant

• Current Assignee: Sonos, Inc.
• Original Assignee: Sonos, Inc.
• Inventors: Millington, Nicholas A.J.
• Granted Patent: US 9,778,898 B2
• Time in Patent Office: Days
• US Class Current: 709/231
• 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

A system is described for maintaining synchrony of operations among a plurality of devices that have independent clocking arrangements. The system includes a task distribution device that distributes tasks to a synchrony group comprising a plurality of devices that are to perform the tasks distributed by the task distribution device in synchrony. The task distribution device distributes each task to the members of the synchrony group over a network. Each task is associated with a time stamp that indicates a time, relative to a clock maintained by the task distribution device, at which the members of the synchrony group are to execute the task. Each member of the synchrony group periodically obtains from the task distribution device an indication of the current time indicated by its clock, determines a time differential between the task distribution device'"'"'s clock and its respective clock and determines therefrom a time at which, according to its respective clock, the time stamp indicates that it is to execute the task.

Claims

1. A method comprising:

transmitting, by an audio information channelization device, an audio stream in packet form, wherein the audio stream comprises a plurality of audio tracks that have been queued for playback by one or more members of a synchrony group, each audio track comprising a plurality of frames, each frame of the plurality of frames being associated with audio information and a time indicating when to play the audio information of the respective frame;

receiving, by the audio information channelization device, a command, wherein the command identifies one of the plurality of audio tracks, and wherein the command indicates that the synchrony group should cancel playback of the one of the plurality of audio tracks;

based on the received command, ceasing transmission, by the audio information channelization device, of the identified audio track within the audio stream;

based on the received command, transmitting, by the audio information channelization device, a resynchronization instruction, wherein the resynchronization instruction instructs the members of the synchrony group not to play back audio information associated with the identified audio track that has previously been transmitted by the audio information channelization device; and

based on the received command, transmitting, by the audio information channelization device, a next track of the plurality of tracks that has been queued for playback by one or more members of the synchrony group, wherein the time indicating when to play the audio information in a first frame of the next track of the plurality of tracks is a time immediately following a time when the resynchronization command was transmitted.

2. The method of claim 1, wherein the audio stream is transmitted using a multicast transmission methodology.

3. The method of claim 1, wherein the resynchronization instruction specifies a packet number associated with the audio stream, and wherein the resynchronization instruction instructs the members of the synchrony group not to play audio information in the audio stream contained in packets between the identified packet number and the receipt of the resynchronization instruction.

4. The method of claim 1, wherein the resynchronization instruction specifies a time, and wherein the resynchronization instructions instructs the members of the synchrony group not to play audio information associated with the audio track after the identified time.

5. The method of claim 1, wherein the audio information channelization device is a member of the synchrony group.

6. The method of claim 5, wherein the audio information channelization devices plays back the audio information in synchrony with the other members of the synchrony group.

7. The method of claim 1, wherein the resynchronization instruction causes the one or more members of the synchrony group to synchronously skip to a next track of the plurality of audio tracks that have been queued for playback.

8. The method of claim 1, wherein the command is received from a user interface module via a network interface.

9. A tangible computer-readable storage medium having instructions stored thereon that when executed cause an audio information channelization device to:

transmit an audio stream in packet form, wherein the audio stream comprises a plurality of audio tracks that have been queued for playback by one or more members of a synchrony group, each audio track comprising a plurality of frames, each frame of the plurality of frames being associated with audio information and a time indicating when to play the audio information of the respective frame;

receive a command, wherein the command identifies one of the plurality of audio tracks, and wherein the command indicates that the synchrony group should cancel playback of the one of the plurality of audio tracks;

based on the received command, cease transmission of the identified audio track within the audio stream;

based on the received command, transmit a resynchronization instruction, wherein the resynchronization instruction instructs the members of the synchrony group not to play back audio information associated with the identified audio track that has previously been transmitted by the audio information channelization device; and

based on the received command, transmit a next track of the plurality of tracks that has been queued for playback by one or more members of the synchrony group, wherein the time indicating when to play the audio information in a first frame of the next track of the plurality of tracks is a time immediately following a time when the resynchronization command was transmitted.

10. The computer-readable medium of claim 9, wherein the audio stream is transmitted using a multicast transmission methodology.

11. The computer-readable medium of claim 9, wherein the resynchronization instruction specifies a packet number associated with the audio stream, and wherein the resynchronization instruction instructs the members of the synchrony group not to play audio information in the audio stream contained in packets between the identified packet number and the receipt of the resynchronization instruction.

12. The computer-readable medium of claim 9, wherein the resynchronization instruction specifies a time, and wherein the resynchronization instructions instructs the members of the synchrony group not to play audio information associated with the audio track after the identified time.

13. The computer-readable medium of claim 9, wherein the audio information channelization device is a member of the synchrony group.

14. The computer-readable medium of claim 13, wherein the audio information channelization devices plays back the audio information in synchrony with the other members of the synchrony group.

15. The computer-readable medium of claim 9, wherein the resynchronization instruction causes the one or more members of the synchrony group to synchronously skip to a next track of the plurality of audio tracks that have been queued for playback.

16. The computer-readable medium of claim 9, wherein the command is received from a user interface module via a network interface.

17. An audio information channelization device comprising:

a network interface configured to transmit an audio stream in packet form, wherein the audio stream comprises a plurality of audio tracks that have been queued for playback by one or more members of a synchrony group, each audio track comprising a plurality of frames, each frame of the plurality of frames being associated with audio information and a time indicating when to play the audio information of the respective frame;

a control module configured to;

receive, via the network interface, a command, wherein the command identifies one of the plurality of audio tracks, and wherein the command indicates that the synchrony group should cancel playback of the one of the plurality of audio tracks;

based on the received command, cause the network interface to cease transmission of the identified audio track within the audio stream;

based on the received command, transmit a resynchronization instruction via the network interface, wherein the resynchronization instruction instructs the members of the synchrony group not to play back audio information associated with the identified audio track that has previously been transmitted by the audio information channelization device; and

based on the received command, transmit, via the network interface, a next track of the plurality of tracks that has been queued for playback by one or more members of the synchrony group, wherein the time indicating when to play the audio information in a first frame of the next track of the plurality of tracks is a time immediately following a time when the resynchronization command was transmitted.

18. The audio information channelization device of claim 17, wherein the audio stream is transmitted using a multicast transmission methodology.

19. The audio information channelization device of claim 17, wherein the resynchronization instruction specifies a packet number associated with the audio stream, and wherein the resynchronization instruction instructs the members of the synchrony group not to play audio information in the audio stream contained in packets between the identified packet number and the receipt of the resynchronization instruction.

20. The audio information channelization device of claim 17, wherein the resynchronization instruction specifies a time, and wherein the resynchronization instructions instructs the members of the synchrony group not to play audio information associated with the audio track after the identified time.