Data rate smoothing

• US 6,347,094 B1
• Filed: 07/21/1998
• Issued: 02/12/2002
• Est. Priority Date: 07/21/1998
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Gopalakrishnan, Palamalai
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US09/119,835
• Time in Patent Office: 1,302 Days
• Field of Search: 370/407, 370/464, 370/465, 370/468, 370/535, 375/240, 348/405
• US Class Current: 370/464
• CPC Class Codes: H04L 12/6418 Hybrid transport

Abstract

Data rate smoothing is disclosed. In one embodiment, a system includes a real-time encoder and a rate-smoothing mechanism. The real-time encoder has a first layer and a second layer, where the first layer sends packets of data to the second layer at a dynamic bit rate. The mechanism adjusts the dynamic bit rate such that the rate is less than a predetermined maximum rate. In a further embodiment, the second layer also sends the packets to the mechanism, and the system also includes a buffer and a client. The buffer temporarily stores the packets received by the mechanism. The client receives the packets from the mechanism, where the mechanism deletes packets from the buffer when a predetermined backlog threshold is exceeded.

Claims

1. A system comprising:

a real-time encoder having a first layer and a second layer, where the first layer is to send packets of data to the second layer at a dynamic bit rate; and

,

a rate-smoothing mechanism to adjust the dynamic bit rate at which the first layer of the real-time encoder is to send the packets of data to the second layer such that the rate is less than a predetermined maximum rate.

2. The system of claim 1, wherein the second layer of the real-time encoder is to send the packets of the data to the rate-smoothing mechanism, and the system further comprises:

a buffer to temporarily store the packets of the data received by the rate-smoothing mechanism from the second layer of the real-time encoder; and

,

a client to receive the packets of the data from the rate-smoothing mechanism as temporarily stored in the buffer,

such that the rate-smoothing mechanism deletes packets from the buffer when the packets temporarily stored therein exceed a predetermined backlog threshold.

3. The system of claim 1, wherein the first layer of the real-time encoder comprises an upper layer of the real-time encoder coupled to a capture mechanism capturing audio and video content.

4. The system of claim 3, wherein the capture mechanism comprises at least one audio capture hardware card and at least one video capture hardware card.

5. The system of claim 1, wherein the second layer of the real-time encoder comprises a network layer of the real-time encoder, and the system further comprises a queue coupling the first layer of the real-time encoder to the second layer of the real-time encoder.

6. The system of claim 2, further comprising a client proxy coupling the client to the rate-smoothing mechanism.

7. The system of claim 2, wherein the client is coupled to the rate-smoothing mechanism via the Internet.

8. The system of claim 2, wherein client is coupled to the rate-smoothing mechanism via TCP/IP.

9. The system of claim 3, wherein the predetermined maximum rate is a predetermined percentage over an advertised arrival bit rate to the first layer of the real-time encoder from the capture mechanism.

10. The system of claim 2, wherein the predetermined backlog threshold is determined as an oldest packet temporarily stored in the buffer being older than the current time by a predetermined length of time.

11. A method comprising:

sending captured data as packets of data at a dynamic bit rate;

adjusting the dynamic bit rate at which the packets of data are sent such that the rate is less than a predetermined maximum rate;

buffering the packets of data;

deleting at least one packet of data when the packets as buffered exceed a predetermined backlog threshold; and

,

sending the packets of data as buffered to a client.

12. The method of claim 11, wherein sending captured data as packets of data comprises:

capturing the data; and

,

receiving the captured data.

13. The method of claim 11, wherein sending captured data as packets of data comprises queuing the packets of data.

14. The method of claim 11, wherein adjusting the dynamic bit rate comprises measuring arrival of the packets of data as the packets are sent for each of a series of predetermined periods of time.

15. The method of claim 11, wherein deleting at least one packet of data comprises deleting a predetermined percentage of the packets of data.

16. The method of claim 11, wherein sending the packets of data as buffered to a client comprises sending the packets of data to the client via a client proxy.

17. The method of claim 11, wherein the predetermined maximum rate is a predetermined percentage over an advertised arrival bit rate.

18. The method of claim 11, wherein the predetermined backlog threshold is determined as an oldest buffered packet being older than the current time by a predetermined length of time.

19. A computer comprising:

a real-time encoder having an upper layer and a network layer, where the upper layer is to send packets of data to the network layer at a dynamic bit rate;

a processor;

a computer-readable medium; and

,

a rate-smoothing program executed by the processor from the medium to adjust the dynamic bit rate such that the rate is less than a predetermined maximum rate.

20. The computer of claim 19, wherein the predetermined maximum rate is a predetermined percentage over an advertised arrival bit rate.

21. The computer of claim 19, wherein the rate-smoothing program further is to buffer the packets of data and delete at least one packet of data when the packets as buffered exceed a predetermined backlog threshold.

22. The computer of claim 21, wherein the predetermined backlog threshold is determined as an oldest buffered packet being older than the current time be a predetermined length of time.

23. A computer-readable medium having a computer program stored thereon for execution on a computer having a real-time encoder having an upper layer and a network layer,

where the upper layer is to send packets of data to the network layer at a dynamic bit rate, and

where the program is to adjust the dynamic bit rate such that the rate is less than a predetermined maximum rate.

24. The computer readable medium of claim 23, wherein the predetermined maximum rate is a predetermined percentage over an advertised arrival bit rate.

25. The computer-readable medium of claim 23, wherein the program further is to buffer the packets of data and delete at least one packet of data when the packets as buffered exceed a predetermined backlog threshold.

26. The computer-readable medium of claim 25, wherein the predetermined backlog threshold is determined as an oldest buffered packet being older than the current time be a predetermined length of time.