Playback device

• US 10,289,380 B2
• Filed: 11/06/2018
• Issued: 05/14/2019
• Est. Priority Date: 07/28/2003
• Status: Expired due to Term

• Current Assignee: Sonos, Inc.
• Original Assignee: Sonos, Inc.
• Inventors: Millington, Nicholas A. J.
• Primary Examiner(s): Survillo, Oleg
• Application Number:
  US16/181,342
• Publication Number:
  US 20190073189A1
• Time in Patent Office: 189 Days
• Field of Search: 709219, 709220, 709231
• 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:

a first zone player operating as a standalone zone player that is configured to play back audio individually rather than in synchrony with another zone player, wherein the first zone player comprises a local clock that provides a clock time of the first zone player;

while operating as a standalone zone player, receiving a request to enter into a synchrony group with at least a second zone player that is communicatively coupled with the first zone player over a local area network (LAN), wherein the second zone player comprises its own respective local clock that provides a respective clock time of the second zone player;

in response to receiving the request to enter into the synchrony group, entering into the synchrony group with the second zone player and transitioning from operating as a standalone zone player to operating as a slave zone player of the synchrony group that is configured to play back audio in synchrony with the second zone player;

while operating as the slave zone player of the synchrony group;

receiving a series of clock-information messages from the second zone player over the LAN, wherein individual respective clock-information messages in the series of clock-information messages include at least one respective reading of the clock time of the local clock of the second zone player;

based on the received series of clock-information messages, regularly adjusting the clock time of the local clock of the first zone player to track that of the local clock of the second zone player;

receiving, from the second zone player over the LAN, (a) audio information for at least a first audio track and (b) playback timing information associated with the audio information for the first audio track that comprises an indicator of a first future time, relative to the clock time of the local clock of the second zone player, at which the first and second zone players are to initiate synchronous playback of the audio information for the first audio track;

buffering the audio information for the first audio track; and

when the adjusted clock time of the local clock of the first zone player reaches the first future time, initiating synchronous playback of the audio information for the first audio track with the second zone player.

2. The method of claim 1, wherein receiving the audio information and the playback timing information from the second zone player over the LAN comprises:

receiving the playback timing information in a separate communication from the audio information.

3. The method of claim 1, wherein the audio information for the first audio track comprises a series of frames, wherein an individual frame includes a respective portion of the received audio information for the first audio track, and wherein the indicator of the first future time corresponds to a first frame in the series of frames.

4. The method of claim 3, wherein the playback timing information further comprises, for an individual subsequent frame in the series of frames, an indicator of a respective future time, relative to the clock time of the local clock of the second zone player, at which the individual subsequent frame is to be synchronously played back by the first and second zone players, and wherein the method further comprises:

for an individual subsequent frame in the series of frames, playing back the individual subsequent frame when the clock time of the first zone player reaches the respective future time at which the individual subsequent frame is to be synchronously played back by the first and second zone players.

5. The method of claim 1, further comprising:

based on one or both of the series of clock-information messages or the playback timing information received from the second zone player, adjusting a rate at which the first zone player plays back at least a portion of the audio information for the first audio track.

6. The method of claim 5, wherein adjusting the rate at which the first zone player plays back the audio information for the first audio track based on the playback timing information received from the second zone player comprises:

determining an expected playback time of a given sample within the audio information for the first audio track;

comparing the expected playback time of the given sample within the audio information for the first audio track to a future playback time of the given sample as indicated by the playback timing information received from the second zone player and thereby determining that there is a difference in respective rates at which the audio information for the first audio track is being played back by the first and second zone players; and

adjusting the rate at which the first zone player plays back at least a portion of the audio information for the first audio track to compensate for the difference in the respective rates at which the audio information for the first audio track is being played back by the first and second zone players.

7. Tangible, non-transitory computer-readable media comprising instructions stored therein, wherein the instructions, when executed by one or more processors, cause a first zone player to perform a method comprising:

the first zone player operating as a standalone zone player that is configured to play back audio individually rather than in synchrony with another zone player, wherein the first zone player comprises a local clock that provides a clock time of the first zone player;

while operating as a standalone zone player, receiving a request to enter into a synchrony group with at least a second zone player that is communicatively coupled with the first zone player over a local area network (LAN), wherein the second zone player comprises its own respective local clock that provides a respective clock time of the second zone player;

in response to receiving the request to enter into the synchrony group, entering into the synchrony group with the second zone player and transitioning from operating as a standalone zone player to operating as a slave zone player of the synchrony group that is configured to play back audio in synchrony with the second zone player;

while operating as the slave zone player of the synchrony group;

receiving a series of clock-information messages from the second zone player over the LAN, wherein individual respective clock-information messages in the series of clock-information messages include at least one respective reading of the clock time of the local clock of the second zone player;

based on the received series of clock-information messages, regularly adjusting the clock time of the local clock of the first zone player to track that of the local clock of the second zone player;

receiving, from the second zone player over the LAN, (a) audio information for at least a first audio track and (b) playback timing information associated with the audio information for the first audio track that comprises an indicator of a first future time, relative to the clock time of the local clock of the second zone player, at which the first and second zone players are to initiate synchronous playback of the audio information for the first audio track;

buffering the audio information for the first audio track; and

when the adjusted clock time of the local clock of the first zone player reaches the first future time, initiating synchronous playback of the audio information for the first audio track with the second zone player.

8. The tangible, non-transitory computer-readable media of claim 7, wherein receiving the audio information and the playback timing information from the second zone player over the LAN comprises:

receiving the playback timing information in a separate communication from the audio information.

9. The tangible, non-transitory computer-readable media of claim 7, wherein the audio information for the first audio track comprises a series of frames, wherein an individual frame includes a respective portion of the received audio information for the first audio track, and wherein the indicator of the first future time corresponds to a first frame in the series of frames.

10. The tangible, non-transitory computer-readable media of claim 9, wherein the playback timing information further comprises, for an individual subsequent frame in the series of frames, an indicator of a respective future time, relative to the clock time of the local clock of the second zone player, at which the individual subsequent frame is to be synchronously played back by the first and second zone players, and wherein the method further comprises:

for an individual subsequent frame in the series of frames, playing back the individual subsequent frame when the clock time of the first zone player reaches the respective future time at which the individual subsequent frame is to be synchronously played back by the first and second zone players.

11. The tangible, non-transitory computer-readable media of claim 7, wherein the method further comprises:

based on one or both of the series of clock-information messages or the playback timing information received from the second zone player, adjusting a rate at which the first zone player plays back at least a portion of the audio information for the first audio track.

12. The tangible, non-transitory computer-readable media of claim 11, wherein adjusting the rate at which the first zone player plays back the audio information for the first audio track based on the playback timing information received from the second zone player comprises:

determining an expected playback time of a given sample within the audio information for the first audio track;

comparing the expected playback time of the given sample within the audio information for the first audio track to a future playback time of the given sample as indicated by the playback timing information received from the second zone player and thereby determining that there is a difference in respective rates at which the audio information for the first audio track is being played back by the first and second zone players; and

adjusting the rate at which the first zone player plays back at least a portion of the audio information for the first audio track to compensate for the difference in the respective rates at which the audio information for the first audio track is being played back by the first and second zone players.

13. A first zone player comprising:

a network interface that is configured to provide an interconnection with at least one data network;

a local clock that provides a clock time of the first zone player;

at least one processor;

a tangible, non-transitory computer-readable medium comprising program instructions stored therein, wherein the program instructions, when executed by the at least one processor, cause the first zone player to perform functions comprising;

the first zone player operating as a standalone zone player that is configured to play back audio individually rather than in synchrony with another zone player;

while operating as a standalone zone player, receiving a request to enter into a synchrony group with at least a second zone player that is communicatively coupled with the first zone player over a local area network (LAN), wherein the second zone player comprises its own respective local clock that provides a respective clock time of the second zone player;

in response to receiving the request to enter into the synchrony group, entering into the synchrony group with the second zone player and transitioning from operating as a standalone zone player to operating as a slave zone player of the synchrony group that is configured to play back audio in synchrony with the second zone player;

while operating as the slave zone player of the synchrony group;

receiving a series of clock-information messages from the second zone player over the LAN, wherein individual respective clock-information messages in the series of clock-information messages include at least one respective reading of the clock time of the local clock of the second zone player;

based on the received series of clock-information messages, regularly adjusting the clock time of the local clock of the first zone player to track that of the local clock of the second zone player;

receiving, from the second zone player over the LAN, (a) audio information for at least a first audio track and (b) playback timing information associated with the audio information for the first audio track that comprises an indicator of a first future time, relative to the clock time of the local clock of the second zone player, at which the first and second zone players are to initiate synchronous playback of the audio information for the first audio track;

buffering the audio information for the first audio track; and

when the adjusted clock time of the local clock of the first zone player reaches the first future time, initiating synchronous playback of the audio information for the first audio track with the second zone player.

14. The first zone player of claim 13, wherein receiving the request to enter into the synchrony group with at least the second zone player comprises:

receiving the request to enter into the synchrony group with at least the second zone player over the LAN from one or both of (a) a controller device that is communicatively coupled to the first zone player over the LAN or (b) the second zone player.

15. The first zone player of claim 13, wherein entering into the synchrony group with the second zone player comprises:

receiving, from the second zone player over the LAN, a notification that the second zone player is to begin operating as a master zone player of the synchrony group and the first zone player is to begin operating as the slave zone player of the synchrony group.

16. The first zone player of claim 13, wherein receiving the audio information and the playback timing information from the second zone player over the LAN comprises:

receiving the playback timing information in a separate communication from the audio information.

17. The first zone player of claim 13, wherein receiving the audio information from the second zone player over the LAN comprises:

receiving a first portion of the audio information from the second zone player over the LAN before initiating synchronous playback of the audio information for the first audio track and receiving a second portion of the audio information from the second zone player over the LAN after initiating synchronous playback of the audio information for the first audio track.

18. The first zone player of claim 13, wherein the audio information for the first audio track comprises a series of frames, wherein an individual frame includes a respective portion of the received audio information for the first audio track.

19. The first zone player of claim 18, wherein the indicator of the first future time corresponds to a first frame in the series of frames.

20. The first zone player of claim 19, wherein the playback timing information further comprises, for an individual subsequent frame in the series of frames:

an indicator of a respective future time, relative to the clock time of the local clock of the second zone player, at which the individual subsequent frame is to be synchronously played back by the first and second zone players.

21. The first zone player of claim 20, wherein the program instructions, when executed by the at least one processor, cause the first zone player to perform functions comprising, while operating at the slave zone player of the synchrony group:

for an individual subsequent frame in the series of frames, playing back the individual subsequent frame when the clock time of the first zone player reaches the respective future time at which the individual subsequent frame is to be synchronously played back by the first and second zone players.

22. The first zone player of claim 13, wherein the program instructions, when executed by the at least one processor, cause the first zone player to perform functions comprising, while operating at the slave zone player of the synchrony group:

based on one or both of the series of clock-information messages or the playback timing information received from the second zone player, adjusting a rate at which the first zone player plays back at least a portion of the audio information for the first audio track.

23. The first zone player of claim 22, wherein adjusting the rate at which the first zone player plays back the audio information for the first audio track based on the playback timing information received from the second zone player comprises:

determining an expected playback time of a given sample within the audio information for the first audio track;

comparing the expected playback time of the given sample within the audio information for the first audio track to a future playback time of the given sample as indicated by the playback timing information received from the second zone player and thereby determining that there is a difference in respective rates at which the audio information for the first audio track is being played back by the first and second zone players; and

adjusting the rate at which the first zone player plays back at least a portion of the audio information for the first audio track to compensate for the difference in the respective rates at which the audio information for the first audio track is being played back by the first and second zone players.

24. The first zone player of claim 13, wherein the program instructions, when executed by the at least one processor, cause the first zone player to perform functions comprising, while operating at the slave zone player of the synchrony group:

receiving, from the second zone player over the LAN, a command to terminate playback of the first audio track; and

in response to receiving the command to terminate, terminating playback of the audio information for the first audio track.

25. The first zone player of claim 24, wherein at least a portion of the audio information for the first audio track is buffered at the first zone player at the time of receiving the command to terminate, and wherein the program instructions, when executed by the at least one processor, cause the first zone player to perform functions comprising, while operating at the slave zone player of the synchrony group:

in response to receiving the command to terminate, also discarding any audio information for the first audio track that is buffered at the first zone player.

26. The first zone player of claim 13, wherein the program instructions, when executed by the at least one processor, cause the first zone player to perform functions comprising, while operating at the slave zone player of the synchrony group:

while still engaging in synchronous playback of the audio information for the first audio track, receiving, from the second zone player over the LAN, (a) audio information for a second audio track and (b) playback timing information associated with the audio information for the second audio track that comprises an indicator of a second future time, relative to the clock time of the local clock of the second zone player, at which the first and second zone players are to initiate synchronous playback of the audio information for the second audio track;

buffering the audio information for the second audio track; and

when the clock time of the local clock of the first zone player reaches the second future time, initiating synchronous playback of the audio information for the second audio track with the second zone player.

27. The first zone player of claim 13, wherein the program instructions, when executed by the at least one processor, cause the first zone player to perform functions comprising, while operating at the slave zone player of the synchrony group:

receiving, from the second zone player over the LAN, a command to adjust an individual volume of the first zone player; and

in response to receiving the command, adjusting the individual volume of the first zone player.

28. The first zone player of claim 13, wherein the program instructions, when executed by the at least one processor, cause the first zone player to perform functions comprising:

while operating as the slave zone player of the synchrony group, receiving, from the second zone player over the LAN, control information that enables the first zone player to begin operating as a master of the synchrony group; and

in response to receiving the control information, transitioning from operating as the slave zone player of the synchrony group to operating as the master of the synchrony group.

29. The first zone player of claim 13, wherein the program instructions, when executed by the at least one processor, cause the first zone player to perform functions comprising:

while operating as the slave zone player of the synchrony group, receiving a request to disengage from the synchrony group;

in response to receiving the request to disengage from the synchrony group, disengaging from the synchrony group and transitioning from operating as the slave zone player of the synchrony group to operating as a standalone zone player.

30. The first zone player of claim 13, wherein receiving the series of clock-information messages from the second zone player over the LAN comprises:

periodically requesting, from the second zone player, an indication of the clock time of the local clock of the second zone player; and

as a result of periodically requesting an indication of the clock time of the local clock of the second zone player, periodically receiving, from the second zone player over the LAN, one of the clock-information messages of the series of clock-information messages.