Patent ID: 11876847
Assignee: D&M HOLDINGS, INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H  G | IPC H

Claim 14:
15. A media rendering system comprising:
a first media rendering device comprising:
a first network interface configured to communicate with a network;
a first audio rendering buffer configured to store audio samples;
a first local timing oscillator; and
a first digital-to-analog converter configured to receive multiple audio samples from the first audio rendering buffer and to receive a clock signal from the first local timing oscillator; and
a second media rendering device configured to communicate via the network with the first media rendering device, the second media rendering device comprising:
a second network interface configured to communicate with the network;
a second audio rendering buffer configured to store audio samples;
a second local timing oscillator;
a second digital-to-analog converter configured to receive multiple audio samples from the second audio rendering buffer and to receive a clock signal from the second local timing oscillator; and
a processor and a memory configured to store non-transitory instructions that, when executed by the processor, cause the processor to:
at a first time s1, send a request for a current audio sample index of an audio stream from the first media rendering device;
at a second time s2, receive a first current sample index value from the first media rendering device;
calculate a network transmission latency as a difference between s1 and s2;
an updated first media rendering device internal sample index value based on the network transmission latency and a sampling rate of the audio stream; and
seta second media rendering device internal sample index to the updated first media rendering device internal sample index value,

wherein the second media rendering device internal sample index is a sample parameter referring to a sequential number used to identify an audio sample, and
wherein the second media rendering device internal sample index corresponds to a measure of time and is associated with an offset to a corresponding local playback buffer.