Granted Patent B1

US 7,934,239 · App. 12/271,142 · Granted Apr 26, 2011

Abstract

Claims (100)

1. A method to operate a video resource daisy-chain access system, comprising:

requesting from a coordinator access instructions for a client to receive a broadcast stream from a broadcast source;

connecting to the broadcast source, or connecting to a re-broadcasting client already receiving the broadcast stream, as instructed by the coordinator;

playing back on the client the received broadcast stream;

periodically sending to the coordinator the last played back time stamp of the received broadcast stream;

periodically receiving at a client, from the coordinator, the time stamp of the most delayed client received by the coordinator from all clients;

receiving a playback time stamp from the one or more clients, and adding half of the round trip time to the time stamp and storing the time stamp in a time stamp store;

incrementing each stored time stamp at a periodic interval;

periodically selecting the most delayed time stamp among all the stored time stamps;

adding half of the round trip time of the one or more clients to the most delayed time stamp and sending the resulting time stamp to the one or more clients; and

testing to determine if the difference between the most delayed time stamp and the last played back time stamp of the received broadcast stream is bigger than an acceptable threshold, wherein

if the difference of the test is not bigger than the acceptable threshold, then no playback adjustment is made to the received broadcast stream,

if the difference of the test is bigger than the acceptable threshold, then pausing playback of the received broadcast stream of the client until the time stamp of the most delayed client is within the acceptable threshold.

2. The method of claim 1 , further comprising:

registering with the coordinator as a potential re-broadcasting client for broadcasting to one or more new clients; and

accepting connection requests from one or more new clients for re-broadcasting of the received broadcast stream.

3. The method of claim 1 , further comprising:

sending information to the coordinator concerning the effective downlink bandwidth for one or more clients; and

adjusting the data compression bit-rate of a re-broadcasting client to accommodate the slowest downlink bandwidth of a client of the one or more clients.

4. The method of claim 1 , further comprising:

detecting the unavailability of a re-broadcasting client needed by at least one client; and

sending reconnecting information to the at least one client to receive a broadcast stream from another re-broadcasting client or the broadcast source.

5. A method to operate a video resource daisy-chain access system, comprising:

requesting from a coordinator access instructions for a client to receive a broadcast stream from a broadcast source;

connecting to the broadcast source, or connecting to a re-broadcasting client already receiving the broadcast stream, as instructed by the coordinator;

playing back on the client the received broadcast stream;

periodically sending one or more probes by the coordinator to one or more clients to calculate a round trip time;

receiving a playback time stamp from the one or more clients, and adding half of the round trip time to the time stamp and storing the time stamp in a time stamp store;

incrementing each stored time stamp at a periodic interval;

periodically selecting the most delayed time stamp among all the stored time stamps;

adding half of the round trip time of the one or more clients to the most delayed time stamp and sending the resulting time stamp to the one or more clients; and

testing to determine if the difference between the most delayed time stamp and the last played back time stamp of the received broadcast stream is bigger than an acceptable threshold, wherein

if the difference of the test is not bigger than the acceptable threshold, and if the playback of the received broadcast stream hasn't started yet or was paused, then playback of the received broadcast stream is started or resumed,

if the difference of the test is not bigger than the acceptable threshold and the playback of the received broadcast stream was in progress, then no playback adjustment is made to the received broadcast stream, or

if the difference of the test is bigger than the acceptable threshold, then pausing playback of the received broadcast stream of the client until the time stamp of the most delayed client is within the acceptable threshold.

6. A method to operate a video resource daisy-chain access system, comprising:

requesting from a coordinator access instructions for a client to receive a broadcast stream from a broadcast source;

connecting the client to the broadcast source, or a re-broadcasting client already receiving the broadcast stream, as instructed by the coordinator;

playing back on the client the received broadcast stream;

periodically sending to the coordinator the last played back time stamp of the received broadcast stream;

periodically receiving at a client, from the coordinator, the time stamp of the most delayed client received by the coordinator from all clients; and

testing to determine if the difference between the most delayed time stamp and the last played back time stamp of the received broadcast stream is bigger than an acceptable threshold, wherein

if the difference of the test is not bigger than the acceptable threshold, then no playback adjustment is made to the received broadcast stream,

if the difference of the test is bigger than the acceptable threshold, then pausing playback of the received broadcast stream of the client until the time stamp of the most delayed client is within the acceptable threshold.

7. The method of claim 6 , further comprising:

periodically sending one or more probes by the coordinator to one or more clients to calculate a round trip time;

receiving a playback time stamp from the one or more clients, and half of the round trip time to the time stamp and storing the time stamp in a time stamp store;

incrementing each stored time stamp at a periodic interval;

periodically selecting the most delayed time stamp among all the stored time stamps; and

adding half of the round trip time of the one or more clients to the most delayed time stamp and sending the resulting time stamp to the one or more clients.

8. The method of claim 6 wherein the operation of registering with the coordinator as a potential re-broadcasting client for new clients includes announcing an available uplink bandwidth to the coordinator for a future reference.

9. The method of claim 6 , further comprising:

registering with the coordinator as a potential re-broadcasting client for new clients; and

accepting connection requests from new clients for re-broadcasting of the received broadcast stream.

10. The method of claim 6 , further comprising:

sending information to the coordinator concerning the effective downlink bandwidth for at least one client; and

adjusting the data compression bit-rate of a re-broadcasting client to accommodate the slowest downlink bandwidth to a plurality of clients.

11. The method of claim 6 , further comprising:

detecting the unavailability of a re-broadcasting client needed by at least one client; and

sending reconnecting information to the at least one client to receive a broadcast stream from another re-broadcasting client or the broadcast source.

12. The method of claim 6 wherein adjusting the playback of a client includes adjusting the playback of a broadcast stream from a buffer in the client.

13. The method of claim 6 wherein adjusting the playback of a client includes changing the re-broadcasting client for the client to a second re-broadcasting client or the broadcast source.

14. A video resource daisy-chain access system, comprising:

a coordinator for organizing a daisy-chain video resource access system and synchronizing video playback between the clients;

a broadcasting source having a communication link with the coordinator;

a first client having a communication link with the coordinator and a communication link with the broadcasting source;

a second client having a communication link with the coordinator and a communication link with the first client;

means for periodically sending one or more probes by the coordinator to one or more clients to calculate a round trip time;

means for receiving a playback time stamp from the one or more clients, and adding half of the round trip time to the time stamp and storing the time stamp in a time stamp store;

means for incrementing each stored time stamp at a periodic interval;

means for periodically selecting the most delayed time stamp among all the stored time stamps;

means for adding half of the round trip time of the one or more clients to the most delayed time stamp and sending the resulting time stamp to the one or more clients; and

means for testing to determine if the difference between the most delayed time stamp and the last played back time stamp of the received broadcast stream is bigger than an acceptable threshold, wherein

if the difference of the test is not bigger than the acceptable threshold, then no playback adjustment is made to the received broadcast stream,

if the difference of the test is bigger than the acceptable threshold, then pausing playback of the received broadcast stream of the client until the time stamp of the most delayed client is within the acceptable threshold.

15. The system of claim 14 , further comprising:

a third client having a communication link with the coordinator and a communication link with the second client.

16. The system of claim 14 , further comprising:

a module in a client to register with the coordinator as a potential re-broadcasting client for new clients; and

a module in the client to accept connection requests from one or more new clients for re-broadcasting of the received broadcast stream.

17. The system of claim 14 , further comprising:

a module in a client to send information to the coordinator concerning the effective downlink bandwidth for the client; and

a module in a re-broadcasting client to adjust the data compression bit-rate of the re-broadcasting client to accommodate the slowest downlink bandwidth to a plurality of clients.

18. The system of claim 14 , further comprising:

a module in the coordinator to detect the unavailability of a re-broadcasting client needed by at least one client; and

a module in the coordinator to send reconnecting information to the at least one client to receive a broadcast stream from another re-broadcasting client or the broadcast source.

19. A video resource daisy-chain access system, comprising:

a coordinator for organizing a daisy-chain video resource access system and synchronizing video playback between the clients;

a broadcasting source having a communication link with the coordinator;

a first client having a communication link with the coordinator and a communication link with the broadcasting source;

a second client having a communication link with the coordinator and a communication link with the first client;

a module to periodically send one or more probes by the coordinator to one or more clients to calculate a round trip time;

a module to receive a playback time stamp from the one or more clients, and add half of the round trip time to the time stamp and store the time stamp in a time stamp store;

means for incrementing each stored time stamp at a periodic interval;

means for periodically selecting the most delayed time stamp among all the stored time stamps;

means for adding half of the round trip time of the one or more clients to the most delayed time stamp and sending the resulting time stamp to the one or more clients; and

means for testing to determine if the difference between the most delayed time stamp and the last played back time stamp of the received broadcast stream is bigger than an acceptable threshold, wherein

if the difference of the test is not bigger than the acceptable threshold, and if the playback of the received broadcast stream hasn't started yet or was paused, then playback of the received broadcast stream is started or resumed,

if the difference of the test is not bigger than the acceptable threshold and the playback of the received broadcast stream was in progress, then no playback adjustment is made to the received broadcast stream, or

if the difference of the test is bigger than the acceptable threshold, then pausing playback of the received broadcast stream of the client until the time stamp of the most delayed client is within the acceptable threshold.

Assignments (9)