Method and apparatus for synchronization of digital multimedia packets
First Claim
1. A method of synchronizing the initiation of playback of packetized multimedia data received asynchronously in a receiver from a transmitter, comprising the steps of:
- providing an encoder in the transmitter and a timer and a decoder in each receiver;
defining each data packet for transmission over a medium to include at least a packet sequence number and a packet retransmit number associated with the data packet;
acknowledging, at each receiver after transmission of a data packet, receipt of a valid received data packet and a correct packet sequence number associated therewith;
determining whether a reserve buffer in the receiver configured for containing a first threshold number M received packets is full; and
synchronizing the initiation of playback of the multimedia data in each receiver according to the arrival time of a first received data packet having a zero-valued retransmit number.
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Accused Products
Abstract
A method and apparatus is provided for synchronizing both the initiation of playback of digital multimedia data in one or more receivers and the rate of playback of the digital multimedia data in the one or more receivers, all receiving the digital multimedia data from a single transmitter, without transmitting clock or timing signals to the receiver(s). An exemplary embodiment is described using the AC powerline as a medium of transmission, although the method and apparatus are adaptable to a variety of communication media.
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Citations
39 Claims
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1. A method of synchronizing the initiation of playback of packetized multimedia data received asynchronously in a receiver from a transmitter, comprising the steps of:
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providing an encoder in the transmitter and a timer and a decoder in each receiver;
defining each data packet for transmission over a medium to include at least a packet sequence number and a packet retransmit number associated with the data packet;
acknowledging, at each receiver after transmission of a data packet, receipt of a valid received data packet and a correct packet sequence number associated therewith;
determining whether a reserve buffer in the receiver configured for containing a first threshold number M received packets is full; and
synchronizing the initiation of playback of the multimedia data in each receiver according to the arrival time of a first received data packet having a zero-valued retransmit number. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of synchronizing the real time playback of packetized multimedia data received asynchronously in one or more receivers from a transmitter, comprising the steps of:
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providing an encoder in the transmitter and a timer and a decoder in each receiver;
defining each data packet for transmission over a medium to include at least a packet sequence number and a packet retransmit number associated with the data packet;
acknowledging, at each receiver after transmission of a data packet, receipt of a valid received data packet and a correct packet sequence number associated therewith;
determining whether a reserve buffer in the receiver configured for containing a first threshold number M received packets is full; and
synchronizing the rate of playback of the multimedia data in each receiver according to a measured time difference between an operating rate of the encoder and an operating rate of the decoder. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method of synchronizing the real time playback of packetized multimedia data received asynchronously in one or more receivers from a transmitter, comprising the steps of:
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providing an encoder in the transmitter and a timer and a decoder in each receiver;
defining each data packet for transmission over a medium to include at least a packet sequence number and a packet retransmit number associated with the data packet;
acknowledging, at each receiver after transmission of a data packet, receipt of a valid received data packet and a correct packet sequence number associated therewith;
determining whether a reserve buffer in the receiver configured for containing a first threshold number M received packets is full;
synchronizing the initiation of playback of the multimedia data in each receiver according to the arrival time of a first received data packet having a zero-valued retransmit number; and
synchronizing the rate of playback of the multimedia data in each receiver according to a measured time difference between an operating rate of the encoder and an operating rate of the decoder. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31)
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32. Apparatus for synchronizing the initiation of playback of packetized multimedia data received asynchronously from a transmitter, comprising:
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a data packet defined for transmission over a medium and having at least a packet sequence number and a packet transmit number associated with the data packet;
a receiver having a timer and a decoder, wherein the decoder operates at a clock rate that is the same as the clock rate of an encoder in the transmitter but independent therefrom;
means for acknowledging, at each receiver after transmission of a data packet, receipt of a valid received data packet and a correct packet sequence number associated therewith; and
means for synchronizing the initiation of playback of the multimedia data in each receiver according to the arrival time of a first received data packet having a zero-valued retransmit number. - View Dependent Claims (33, 34)
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35. Apparatus for synchronizing real time playback of packetized multimedia data received asynchronously in one or more receivers from a transmitter, comprising:
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a data packet defined for transmission over a medium and having at least a packet sequence number and a packet transmit number associated with the data packet;
a receiver having a timer and a decoder, wherein the decoder operates at a clock rate that is the same as the clock rate of an encoder in the transmitter but independent therefrom;
means for acknowledging, at each receiver after transmission of a data packet, receipt of a valid received data packet and a correct packet sequence number associated therewith;
means for synchronizing the rate of playback of the multimedia data in each receiver according to a measured time difference between an operating rate of the encoder and an operating rate of the decoder. - View Dependent Claims (36, 37, 38, 39)
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Specification