Playback Device Synchrony Group States

• US 20180253277A1
• Filed: 05/07/2018
• Published: 09/06/2018
• 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 10,324,684 B2
• Time in Patent Office: Days
• 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

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 system comprising:

an audio information source configured to execute functions comprising media content to a data network for playback by a synchrony group comprising a first zone player and a second zone player, wherein the first zone player is a master of the synchrony group and the second zone player is a slave in the synchrony group;

the first zone player, wherein the first zone player is configured to execute functions comprising;

(i) receiving the media content via the data network, (ii) transmitting the media content via the data network to the second zone player, and (iii) playing the media content; and

the second zone player, wherein the second zone player is configured to execute functions comprising;

(i) receiving the media content from the first zone player, (ii) determining a timing difference between a clock of the second zone player and a clock of the first zone player, and (iii) playing the media content in synchrony with the first zone player based on the timing difference between a clock of the second zone player and a clock of the first zone player.

2. The system of claim 1, wherein the first zone player is configured to execute further functions comprising storing status information indicating membership in the synchrony group.

3. The system of claim 2, wherein the synchrony group is a first synchrony group, and wherein the first zone player is configured to perform further functions comprising:

(i) migrating from the first synchrony group to a second synchrony group in response to control information received from a controller device, and (ii) wherein after migrating from the first synchrony group to the second synchrony group, transmitting status information to the controller device indicating membership in the second synchrony group.

4. The system of claim 1, further comprising a third zone player, wherein the third zone player is a slave member of the synchrony group, and wherein the third zone player is configured to execute functions comprising:

(i) receiving the media content from the first zone player, (ii) determining a timing difference between a clock of the third zone player and a clock of the first zone player, and (iii) playing the media content in synchrony with the first zone player based on the timing difference between a clock of the third zone player and a clock of the first zone player.

5. The system of claim 1, wherein the first zone player is configured to execute further functions comprising:

(i) determining whether the second zone player should be the master of the synchrony group based on one or more of processor load of the first zone player or network congestion metrics, and (ii) in response to determining that the second zone player should be the master of the synchrony group, sending one or more control messages to the second zone player to cause the second zone player to become the master of the synchrony group.

6. The system of claim 1, wherein the first zone player and the second zone player are both configured to perform further functions comprising transmitting status information to a controller device indicating membership in the synchrony group.

7. The system of claim 1, wherein the first zone player transmitting the media content via the data network to the second zone player comprises the first zone player transmitting the media content via a multi-cast network address.

8. The system of claim 1, wherein the first zone player is configured to execute further functions comprising generating a plurality of time-stamped frames comprising the media content, and wherein the first zone player transmitting the media content via the data network to the second zone player comprises the first zone player transmitting the plurality of time-stamped frames comprising the media content to the second zone player.

9. The system claim 1, wherein the second zone player playing the media content in synchrony with the first zone player based on the timing difference between a clock of the second zone player and a clock of the first zone player comprises the second zone player playing the media content in synchrony with the first zone player based on (i) the timing difference between a clock of the second zone player and a clock of the first zone player and (ii) a time delay implemented by the second zone player.

10. The system of claim 1, wherein the timing difference is based at least in part on a network latency estimate.

11. In a media playback network comprising an audio information source, a first zone player, and a second zone player, a method comprising:

the audio information source transmitting media content for playback by a synchrony group comprising the first zone player and the second zone player, wherein the first zone player is a master of the synchrony group and the second zone player is a slave in the synchrony group;

the first zone player (i) receiving the media content via a data network, (ii) transmitting the media content via the data network to the second zone player, and (iii) playing the media content; and

the second zone player (i) receiving the media content from the first zone player, (ii) determining a timing difference between a clock of the second zone player and a clock of the first zone player, and (iii) playing the media content in synchrony with the first zone player based on the timing difference between a clock of the second zone player and a clock of the first zone player.

12. The method of claim 11, further comprising the first zone player storing status information indicating membership in the synchrony group.

13. The method of claim 11, wherein the first zone player transmitting the media content via the data network to the second zone player comprises the first zone player transmitting the media content via a multi-cast network address.

14. The method of claim 11, wherein the synchrony group is a first synchrony group, and wherein the method further comprises:

the first zone player (i) migrating from the first synchrony group to a second synchrony group in response to control information received from a controller device, and (ii) wherein after migrating from the first synchrony group to the second synchrony group, transmitting status information to the controller device indicating membership in the second synchrony group.

15. The method of claim 11, wherein the method further comprises:

the first zone player and the second zone player transmitting status information to a controller device indicating membership in the synchrony group.

16. The method of claim 11, further comprising:

the first zone player (i) determining whether the second zone player should be the master of the synchrony group, and (ii) in response to determining that the second zone player should be the master of the synchrony group, sending one or more control messages to the second zone player to cause the second zone player to become the master of the synchrony group.

17. The method of claim 16, wherein determining whether the second zone player should be the master of the synchrony group comprises determining whether the second zone player should be the master of the synchrony group based on one or more of processor load of the first zone player or network congestion metrics.

18. The method of claim 11, wherein the timing difference is based at least in part on a network latency estimate.

19. The method of claim 11, wherein the second zone player playing the media content in synchrony with the first zone player based on the timing difference between a clock of the second zone player and a clock of the first zone player comprises the second zone player playing the media content in synchrony with the first zone player based on (i) the timing difference between a clock of the second zone player and a clock of the first zone player and (ii) a time delay implemented by the second zone player.

20. The method of claim 11, further comprising the first zone player generating a plurality of time-stamped frames comprising the media content, and wherein the first zone player transmitting the media content via the data network to the second zone player comprises the first zone player transmitting the plurality of time-stamped frames comprising the media content to the second zone player.

21. The method of claim 11, further comprising the first zone player and the second zone player buffering at least portions of the media content.

22. The method of claim 11, wherein the synchrony group further comprises a third zone player, wherein the third zone player is a slave member of the synchrony group, and wherein the method further comprises the third zone player (i) receiving the media content from the first zone player, (ii) determining a timing difference between a clock of the third zone player and a clock of the first zone player, and (iii) playing the media content in synchrony with the first zone player based on the timing difference between a clock of the third zone player and a clock of the first zone player.

23. The method claim 22, wherein the third zone player playing the media content in synchrony with the first zone player based on the timing difference between a clock of the third zone player and a clock of the first zone player comprises the third zone player playing the media content in synchrony with the first zone player based on (i) the timing difference between a clock of the third zone player and a clock of the first zone player and (ii) a time delay implemented by the third zone player.

24. The method of any of claim 11, further comprising:

the second zone player (i) sending a notification to the first zone player that the second zone player is leaving the synchrony group and (ii) leaving the synchrony group; and

in response to receiving the notification, the first zone player (i) terminating transmission of the media content to the second zone player and (ii) sending one or more status messages to a controller device informing the controller device that the second zone player has left the synchrony group.

25. The method of claim 11, wherein the media content is a first media content, and wherein the method further comprises:

the first zone player receiving a request to play a second media content;

in response to receiving the request to play the second media content, the first zone player (i) stopping playback of the first media content, (ii) playing the second media content, and (iii) transmitting the second media content to the second zone player; and

the second zone player (i) receiving the second media content from the first zone player, (ii) determining a timing difference between a clock of the second zone player and a clock of the first zone player, and (iii) playing the second media content in synchrony with the first zone player based on the timing difference between a clock of the second zone player and a clock of the first zone player.