Abstract: Relay devices and sink devices that provide synchronized audio and/or video outputs are described. A relay device receives a first communication packet from a source device. The first communication packet includes a data frame. A timestamp is generated. The timestamp is an estimate of a time at which content defined by the data frame will be “played.” A second communication packet is generated that includes the data frame and the generated timestamp. The second communication packet is transmitted from the relay device. In one implementation, the generated timestamp is received by a plurality of sink devices, and is used to synchronize output signals (e.g., sound and/or video images) of the sink devices. In another implementation, the generated timestamp is received by a sink device, and is used to synchronize an output signal of the sink device with an output signal of the relay device.

Abstract: Methods, systems, and apparatuses for synchronizing one or more output/sink devices are described. In each sink device, a communication packet is received from a source device. The communication packet includes data and a source clock timestamp. A local clock signal is generated that is synchronized with a source clock signal of the source device. The data is decoded using a codec. At least one delay and the source clock timestamp are subtracted from a current value of the local clock signal to generate a local latency value. A difference between a desired latency value and the local latency value is determined. A rate of a clock signal of the codec is adjusted according to the determined difference. Because each sink device adjusts its latency to a common desired latency value, the sink devices are thereby synchronized.

Abstract: Relay devices and sink devices that provide synchronized audio and/or video outputs are described. A relay device receives a first communication packet from a source device. The first communication packet includes a data frame. A timestamp is generated. The timestamp is an estimate of a time at which content defined by the data frame will be “played.” A second communication packet is generated that includes the data frame and the generated timestamp. The second communication packet is transmitted from the relay device. In one implementation, the generated timestamp is received by a plurality of sink devices, and is used to synchronize output signals (e.g., sound and/or video images) of the sink devices. In another implementation, the generated timestamp is received by a sink device, and is used to synchronize an output signal of the sink device with an output signal of the relay device.

Abstract: Methods, systems, and apparatuses for synchronizing one or more output/sink devices are described. In each sink device, a communication packet is received from a source device. The communication packet includes data and a source clock timestamp. A local clock signal is generated that is synchronized with a source clock signal of the source device. The data is decoded using a codec. At least one delay and the source clock timestamp are subtracted from a current value of the local clock signal to generate a local latency value. A difference between a desired latency value and the local latency value is determined. A rate of a clock signal of the codec is adjusted according to the determined difference. Because each sink device adjusts its latency to a common desired latency value, the sink devices are thereby synchronized.