Playback Devie

Patent metadata

Field	Value
Publication number	US-2022091814-A1
Application number	US-202117540631-A
Country	US
Kind code	A1
Filing date	Dec 2, 2021
Priority date	Jul 28, 2003
Publication date	Mar 24, 2022
Grant date	—

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.

First claim

What is claimed is:

1 . A first data network device comprising:
one or more processors; and tangible, non-transitory computer-readable media comprising program instructions that are executable by the one or more processors such that the first data network device is configured to: receive control information from a second data network device over an asynchronous data network configured to exchange digital data packets, wherein the received control information comprises a direction for the first data network device to enter into a synchrony group with at least a third data network device; and after receiving the control information, enter into the synchrony group with at least the third data network device,
wherein in the synchrony group, the first data network device and the third data network device are configured to playback audio in synchrony based at least in part on (i) audio content, (ii) playback timing information associated with the audio content, wherein the playback timing information is generated by one of the first data network device or the third data network device, and (iii) a determined clock differential between the first data network device and the third data network device, and
wherein the playback timing information is transmitted from the one of the first data network device or the third data network device to the other of the first data network device or the third data network device, wherein the clock differential is determined by one of the first data network device or the third data network device, and wherein the first data network device and the third data network device remain independently clocked while playing back audio in synchrony.

2 . The first data network device of claim 1 , further comprising program instructions that are executable by the one or more processors such that the first data network device is configured to:
transmit status information to the second data network device.

3 . The first data network device of claim 2 , wherein the status information comprises information about a status of the synchrony group after the first data network device has entered into the synchrony group with at least the third data network device.

4 . The first data network device of claim 1 , wherein the second data network device comprises a controller device that is (i) communicatively coupled to the first data network device over the asynchronous data network, and (ii) physically separate from the first data network device and the third data network device.

5 . The first data network device of claim 1 , wherein the first data network device comprises a playback device, and wherein the third data network device comprises a playback device.

6 . The first data network device of claim 1 , further comprising program instructions that are executable by the one or more processors such that the first data network device is configured to, while the first data network device is operating as a group coordinator for the synchrony group:
obtain the audio content from an audio source; and transmit the audio content from the first data network device to the third data network device.

7 . The first data network device of claim 6 , wherein the audio source comprises one of (i) an Internet-based audio source, (ii) the second data network device, or (iii) the third data network device.

8 . The first data network device of claim 1 , further comprising program instructions that are executable by the one or more processors such that the first data network device is configured to, while the first data network device is operating as a group coordinator for the synchrony group:
obtain the audio content from an audio source; generate the playback timing associated with the audio content; and transmit the audio content and the playback timing from the first data network device to the third data network device.

9 . The first data network device of claim 1 , further comprising program instructions that are executable by the one or more processors such that the first data network device is configured to, while the first data network device is operating as a group coordinator for the synchrony group:
transmit time information from the first data network device to the third data network device, wherein the time information is associated with a clock time of a clock at the first data network device.

10 . The first data network device of claim 1 , further comprising program instructions that are executable by the one or more processors such that the first data network device is configured to, while the first data network device is operating as a group coordinator for the synchrony group:
obtain the audio content from an audio source; generate the playback timing associated with the audio content, wherein the playback timing associated with the audio content comprises, for an individual portion of audio content, a time stamp corresponding to a future time relative to a current clock time of a clock at the first data network device at which the first data network device and third data network device are to play the individual portion of audio content; and transmit the audio content and the playback timing from the first data network device to the third data network device, wherein transmitting the audio content and the playback timing from the first data network device to the third data network device comprises transmitting a series of frames from the first data network device to the third data network device, wherein the series of frames comprises individual portions of audio content and the playback timing associated with the individual portions of audio content.

11 . The first data network device of claim 10 , wherein an individual frame of the series of frames comprises (i) a respective portion of audio content and (ii) playback timing corresponding to the respective portion of the audio content.

12 . The first data network device of claim 10 , wherein the playback timing corresponding to a first frame in the series of frames comprises an indicator of a first future time relative to the current clock time of the clock at the first data network device at which the first data network device and the third data network device are to play a corresponding first individual portion of audio content.

13 . The first data network device of claim 12 , wherein the playback timing further comprises, for each subsequent frame in the series of frames after the first frame in the series of frames, an indicator of a respective future time relative to the current clock time of the clock at the first data network device at which the subsequent frame is to be synchronously played back by the first data network device and the third data network device.

14 . The first data network device of claim 1 , wherein the determined clock differential between the first data network device and the third data network device comprises an initial differential between a clock time at the third data network device and a clock time at the first data network device, and wherein the program instructions further comprise program instructions that are executable by the one or more processors such that the first data network device is configured to:
after determining the initial differential between the clock time at the third data network device and the clock time at the first data network device, receiving, from the third data network device over the asynchronous data network, updated time information that includes at least one updated reading of the clock time at the third data network device; and based on the updated time information, determinin

Assignees

• Sonos Inc

Inventors

• Millington Nicholas A J

Classifications

• H04L67/55

  Push-based network services · CPC title

• H04L65/61

  for supporting one-way streaming services, e.g. Internet radio · CPC title

• H04L65/613

  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 title

• H04L65/75

  Media network packet handling · CPC title

• H04L65/612

  for unicast · CPC title