Audio Playback Adjustment

A non-transitory computer-readable medium, wherein the non-transitory computer-readable medium is provisioned with program instructions that, when executed by at least one processor, cause a first playback device to:

• place audio frames representative of audio content in a buffer of the first playback device, each frame comprising respective playback timing information identifying a time, relative to a master clock, to play back the audio frame;
• transmit the audio frames in the buffer to a second playback device for synchronous playback with the first playback device;
• receive a command to adjust playback of the audio content;
• based on the command, identify a range of audio frames previously transmitted by the first playback device to the second playback device for which playback timing information is to be updated;
• select a new start time for the previously transmitted range of audio frames;
• without retransmitting the previously transmitted range of audio frames, transmit (i) an indication of the new start time and (ii) an indication of the range of previously transmitted audio frames to the second playback device and thereby cause the second playback device to update the playback timing information for each audio frame in the range of previously transmitted audio frames based on the new start time;
• update, in the buffer of the first playback device, the playback timing information for each audio frame in the range of previously transmitted audio frames based on the new start time;
• and
• play back each frame in the range of previously transmitted audio frames in synchrony with the second playback device based on the updated playback timing information.

A method implemented by a first playback device, the method comprising:

• placing audio frames representative of audio content in a buffer of the first playback device, each frame comprising respective playback timing information identifying a time, relative to a master clock, to play back the audio frame;
• transmitting the audio frames in the buffer to a second playback device for synchronous playback with the first playback device;
• receiving a command to adjust playback of the audio content;
• based on the command, identifying a range of audio frames previously transmitted by the first playback device to the second playback device for which playback timing information is to be updated;
• selecting a new start time for the previously transmitted range of audio frames;
• without retransmitting the previously transmitted range of audio frames, transmitting (i) an indication of the new start time and (ii) an indication of the range of previously transmitted audio frames to the second playback device and thereby causing the second playback device to update the playback timing information for each audio frame in the range of previously transmitted audio frames based on the new start time;
• updating, in the buffer of the first playback device, the playback timing information for each audio frame in the range of previously transmitted audio frames based on the new start time;
• and
• playing back each frame in the range of previously transmitted audio frames in synchrony with the second playback device based on the updated playback timing information.