System and method for automatic adjustment of streaming video bit rate

• US 20070053446A1
• Filed: 09/22/2005
• Published: 03/08/2007
• Est. Priority Date: 09/02/2005
• Status: Active Grant

• Current Assignee: NETGEAR, Inc.
• Original Assignee: SkipJam Corp. (NETGEAR, Inc.)
• Inventors: Spilo, Michael
• Granted Patent: US 8,218,657 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• CPC Class Codes: G10L 19/24 Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A system and method for automatically sets the encoding bit-rate across a network. The method includes encoding an original media stream with an encoding bit rate having an adjustable rate, transmitting the encoded media stream to a receiver, monitoring a throughput of the encoded media stream, computing an adjustment to the encoding bit rate, and adjusting the encoder'"'"'s encoding bit rate. A throughput monitor (which can be freestanding, part of the transmitter, or part of the receiver), is operable to monitor the encoded media stream, wherein the transmitter is operable to adjust the encoding bit rate using a result of the monitored throughput. The transmitter and receiver both contain a buffer, and respective buffer monitors. Conditions (e.g., overflow, full, empty) at the transmitter or receiver buffer are detected by the respective transmitter or receiver buffer monitor, where upon a repeated condition the encoded bit rate is adjusted higher or lower.

Claims

1. A method for transmitting a media stream over a network comprising the steps of:

providing a transmitter and a receiver connected through the network, wherein the transmitter includes an encoder having an adjustable bit rate;

encoding, by the encoder, with an encoding bit rate an original media stream into an encoded media stream;

transmitting the encoded media stream to the receiver;

monitoring a throughput of the encoded media stream;

computing an adjustment to the encoding bit rate using a result of the monitoring step; and

adjusting the encoding bit rate so as to encode the encoded media stream at an adjusted bit rate.

2. The method of claim 1, wherein the monitoring step includes monitoring the throughput of the encoded media stream at the transmitter.

3. The method of claim 1, wherein the monitoring step includes monitoring the throughput of the encoded media stream at the receiver.

4. The method of claim 1, wherein the step of adjusting is executed as a result of an internal computation by the transmitter.

5. The method of claim 1, wherein the step of adjusting is executed after receiving, from the receiver, a request for a change in the encoding bit rate.

6. The method of claim 1, further including, after the adjusting step, the step of notifying the receiver that an adjustment to the encoding bit rate has been made.

7. The method of claim 1, wherein the providing step further includes providing a plurality of receivers connected to the transmitter through the network, and the transmitting step further includes transmitting the encoded media stream to the plurality of receivers.

8. The method of claim 7, wherein the monitoring step includes monitoring the throughput of the encoded media stream at each of the plurality of receivers.

9. The method of claim 7, wherein the step of adjusting is executed after receiving, from one of the plurality of receivers, a request for a change in the encoding bit rate.

10. The method of claim 7, wherein the encoding step'"'"'s encoding bit rate is a minimum acceptable bit rate common to each of the plurality of receivers.

11. A device for transmitting data over a network comprising:

a transmitter and a receiver in communication over the network;

the transmitter containing a central processing unit, a network interface, and an encoder, the encoder being operable to encode an original media stream, with an encoding bit rate, into an encoded media stream;

the receiver containing a central processing unit, a network interface, and a decoder, the receiver being operable to receive the encoded media stream from the transmitter;

a throughput monitor associated with the network and operable to monitor the encoded media stream, wherein the transmitter is operable to adjust the encoding bit rate using a result of the monitored throughput.

12. The device of claim 11, wherein the throughput monitor is located within the transmitter and monitors the throughput of the encoded media stream at an output of the transmitter network interface.

13. The device of claim 11, wherein the throughput monitor is located within the receiver and monitors the throughput of the received encoded media stream at an input of the receiver network interface.

14. The device of claim 11, wherein the transmitter is further operable to initiate the encoder adjustment in response to an internal computation at the transmitter.

15. The device of claim 11, wherein the receiver is operable to send a request to the transmitter to initiate the encoder adjustment.

16. The device of claim 11, wherein the transmitter is further operable to notify the receiver of the adjustment to the encoding bit rate.

17. The device of claim 11, further comprising a plurality of receivers in communication with the transmitter over the network.

18. The device of claim 17, wherein the throughput monitor is further operable to monitor the throughput at each of the plurality of receivers.

19. The device of claim 17, wherein each of the plurality of receivers is further operable to send a request to the transmitter to initiate the encoder adjustment.

20. The device of claim 17, wherein the encoding step'"'"'s encoding bit rate is a minimum acceptable bit rate common to each of the plurality of receivers.

21. A device for transmitting data over a network comprising:

a transmitter and a receiver in communication over the network;

the transmitter containing a central processing unit, a transmitter buffer, a transmitter buffer monitor, a network interface, and an encoder, the encoder being operable to encode an original media stream, with an encoding bit rate, into an encoded media stream;

the receiver containing a central processing unit, a receiver buffer, a receiver buffer monitor, a network interface, and a decoder, the receiver being operable to receive the encoded media stream from the transmitter; and

wherein the transmitter being operable to adjust the encoding bit rate in response to at least one of a predetermined capacity condition detected by at least one of the receiver buffer monitor and the transmitter buffer monitor.

22. The device of claim 21, wherein if the transmitter buffer monitor detects that the transmitter buffer repeatedly overflows, then the adjusted bit rate is lower than the encoding bit rate.

23. The device of claim 21, wherein if the transmitter buffer monitor detects that the transmitter buffer is repeatedly empty, then the adjusted bit rate is higher than the encoding bit rate.

24. The device of claim 21, wherein if the receiver buffer detects that the receiver buffer is not full for a given period, then the adjusted bit rate is higher than the encoding bit rate.

25. The device of claim 21, wherein if the receiver buffer monitor detects that the receiver buffer is repeatedly empty, then the adjusted bit rate is lower than the encoding bit rate.

26. The device of claim 21, wherein the transmitter is further operable to notify the receiver of an adjustment to the encoding bit rate.

27. A method for transmitting a media stream over a network comprising the steps of:

providing a transmitter and a receiver connected through the network, wherein the transmitter includes a transmitter buffer and an encoder having an adjustable bit rate, and the receiver includes a receiver buffer;

encoding an original media stream by the encoder having an encoding bit rate;

transmitting the encoded media stream to a receiver;

monitoring at least one of the transmitter buffer and the receiver buffer for a predetermined capacity condition;

computing an adjustment to the encoding bit rate when the monitoring step detects the predetermined capacity condition; and

adjusting the encoding bit rate so as to encode the original media stream at an adjusted bit rate.

28. The method of claim 27, wherein the monitoring step further includes monitoring the transmitter buffer, and further includes the step of;

increasing the encoding bit rate, by the transmitter, if the detected predetermined capacity condition includes the transmitter buffer being repeatedly empty.

29. The method of claim 27, wherein the monitoring step includes monitoring the transmitter buffer, and further includes the step of;

decreasing the encoding bit rate, by the transmitter, if the detected predetermined capacity condition is the transmitter buffer is repeatedly full.

30. The method of claim 27, wherein the monitoring step includes monitoring the receiver buffer, and further includes the step of;

decreasing the encoding bit rate, by the transmitter, if the detected predetermined capacity condition is the receiver buffer is repeatedly empty.

31. The method of claim 27, wherein the monitoring step includes monitoring the receiver buffer, and further includes the step of;

increasing the encoding bit rate, by the transmitter, if the detected predetermined capacity condition is the receiver buffer is not repeatedly full.

32. The method of claim 27, further including, after the step of adjusting, the step of notifying the receiver of an adjustment to the encoding bit rate.