Synchronized playback and control of media

Abstract

Methods and systems provide synchronized sharing of multimedia between multiple devices. The multiple devices may form an ad-hoc network for sharing of multimedia. In an embodiment, group members may have playlist manipulation privileges such as pausing, rewinding, fast forwarding, or adding tracks to the playlist. A system may stream or distribute content according to the shared playlist. Playback may be synchronized for group members so that everyone is exposed to a same part of the content as the same time.

What is claimed is: 
     
         1 . A method for synchronizing a digital audio stream for member devices of a group, the method comprising, at a first one of the member devices that form the group:
 maintaining a member list of the member devices of the group;   maintaining a playlist including at least one track for distribution to the member devices;   receiving a command from another one of the member devices;   updating the playlist based on the command;   distributing updates to the playlist to other member devices; and   synchronizing performance of the received command at each member device based on the updates.   
     
     
         2 . The method of  claim 1 , wherein the member devices form a peer-to-peer network. 
     
     
         3 . The method of  claim 1 , further comprising:
 determining an accuracy of a respective clock of each of the member devices;   comparing the accuracy of each of the clocks to determine a most accurate clock;   setting the most accurate clock as a master clock; and   adjusting playback of a track to be consistent with the master clock for each member device other than the member device associated with the master clock.   
     
     
         4 . The method of  claim 1 , further comprising:
 scheduling an anchor time to begin playback of a track; and   distributing the anchor time to each of the member devices.   
     
     
         5 . The method of  claim 4 , further comprising, determining a buffer size prior to the anchor time, wherein the buffer size is defined by a slowest one of the member devices such that the slowest member device is capable of playing the digital audio stream in synchrony with the other member devices. 
     
     
         6 . The method of  claim 1 , further comprising:
 receiving a request for an invitee device to join the group;   updating the member list to include the invitee device; and   distributing a copy of the playlist and at least a portion of a current track to the invitee device.   
     
     
         7 . The method of  claim 6 , further comprising:
 authenticating the invitee device; and   wherein updating the member list is performed if the invitee device is authenticated.   
     
     
         8 . The method of  claim 1 , further comprising:
 determining whether at least one of the members devices contains digital rights to a track on the playlist; and   if none of the member devices contains digital rights to the track, removing the track from the playlist and proceeding to a next track on the playlist.   
     
     
         9 . The method of  claim 1 , further comprising:
 determining whether at least one of the member devices is restricted from receiving a type of track on the playlist; and   if at least one of the member devices is restricted, removing the member device from the group prior to distributing a portion of the type of track.   
     
     
         10 . The method of  claim 1 , further comprising:
 determining whether at least one of the member devices is restricted from receiving a type of track on the playlist; and   if at least one of the members device is restricted, removing all tracks of the type of track from the playlist.   
     
     
         11 . The method of  claim 1 , further comprising:
 if the command is a scrubbing instruction, identifying a point corresponding to the scrubbing of the track on the first one of the member devices; and   sending the point of the track as an anchor time to the other member devices.   
     
     
         12 . The method of  claim 1 , wherein the first one of the member devices is configured to display a user interface to resolve a conflict between a plurality of received commands. 
     
     
         13 . The method of  claim 12 , further comprising:
 if the first one of the member devices departs the group, configuring another one of the member devices to perform functions of the first one of the member devices.   
     
     
         14 . A non-transitory computer-readable medium storing program instructions that, when executed, cause a processor to perform a method, the method comprising, at a first one of the member devices that form a group:
 maintaining a member list of the member devices of the group;   maintaining a playlist including at least one track for distribution to the member devices;   receiving a command from another one of the member devices;   updating the playlist based on the command; and   distributing updates to the playlist to other member devices such that the received command is performed substantially simultaneously at each member device.   
     
     
         15 . The non-transitory computer-readable medium of  claim 14 , the method further comprising:
 determining an accuracy of a respective clock of each of the member devices;   comparing the accuracy of each of the clocks to determine a most accurate clock;   setting the most accurate clock as a master clock; and   adjusting playback of a track to be consistent with the master clock for each member device other than the member device associated with the master clock.   
     
     
         16 . The non-transitory computer-readable medium of  claim 14 , the method further comprising:
 receiving a request for an invitee device to join the group;   updating the member list to include the invitee device; and   distributing a copy of the playlist and at least a portion of a current track to the invitee device.   
     
     
         17 . The non-transitory computer-readable medium of  claim 14 , wherein a master device is configured to display a user interface to resolve a conflict between a plurality of received commands. 
     
     
         18 . A device comprising:
 a memory device to store a member list identifying another connected device as a member of a group and a playlist identifying at least one track for synchronized playback among the devices, and   a processor configured, according to a role of the device when the device has the role of a master device, to cause the device to:
 receive a command to manipulate the playlist from a non-master device; 
 update the playlist based on the command; 
 distribute updates to the playlist to the other connected device; and 
 synchronize a performance of the received command at each device. 
   
     
     
         19 . The device of  claim 18 , wherein the master device is further configured to:
 determine an accuracy of a respective clock of each connected device;   compare the accuracy of each of the clocks to determine a most accurate clock; and   set the most accurate clock as a master clock.   
     
     
         20 . The device of  claim 19 , wherein each connected device is configured to adjust playback of a track to be consistent with the master clock, and wherein to adjust playback, the master device schedules an anchor time to begin playback of a track, and distributes the anchor time to each connected device.