Adjusting sampling rate for encoding

• US 20060244816A1
• Filed: 04/28/2005
• Published: 11/02/2006
• Est. Priority Date: 04/28/2005
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Normile, Jim, Tung, Berkat Shing, Jeong, Hyeonkuk
• Granted Patent: US 7,653,250 B2
• Time in Patent Office: Days
• US Class Current: 348/14.80
• CPC Class Codes: H04N 21/4788 communicating with other users, e.g. chatting arrangements for providing for computer conferences, e.g. chat rooms, to substation in data switching networks H04L12/1813; distributed application using peer-to-peer [P2P] networks H04L67/104
• CPC Class Codes: H04N 21/6377 directed to server one-way streaming services wherein the source is controlled by the destination H04L65/613
• CPC Class Codes: H04N 21/6379 directed to encoder , e.g. for requesting a lower encoding rate
• CPC Class Codes: H04N 21/658 Transmission by the client directed to the server
• CPC Class Codes: H04N 7/147 Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals selecting H04Q
• CPC Class Codes: H04N 7/15 Conference systems

Abstract

Some embodiments provide a method for adjusting a video sampling rate during an video encoding operation. The method receives a metric that quantifies the usage of a computer that performs the video encoding operation. The method computes an adjustment factor based on the metric. In some embodiments the metric is a system idle time. The method defines the video sampling rate based on the adjustment factor. Some embodiments compute the adjustment factor by performing a non-linear operation based on the metric. In some embodiments, the non-linear operation includes performing an integral operation based on the metric. In some embodiments, the non-linear operation includes performing a derivative operation based on the metric. Some embodiments perform more than one operation to compute the adjustment factor. In some embodiments, each operation is assigned a weight.

Claims

1. A method for adjusting a video sampling rate that is used during a video encoding operation, the method comprising:

a) receiving a metric that quantifies the usage of a computer that performs the video encoding operation;

b) computing an adjustment factor based on the metric; and

c) defining the video sampling rate based on the adjustment factor.

2. The method of claim 1, wherein the computing of the adjustment factor comprises using a proportional integral derivative (“

PID”

) operation to compute the adjustment factor based on the received metric.

3. The method of claim 2, wherein the PID operation performs a proportional calculation, an integral calculation, and a derivative calculation, and combines results of said calculations through a set of weighting factors.

4. The method of claim 3, wherein at least one of the weighting factors is set to zero.

5. The method of claim 1, wherein the computing of the adjustment factor comprises using a non-linear calculation to compute the adjustment factor based on the received metric.

6. The method of claim 1, wherein the metric comprises a system idle of the computer.

7. The method of claim 6, wherein the system idle is an idle percentage of a processor of the computer.

8. The method of claim 6, wherein the video sampling rate is not adjusted when the system idle is above a certain threshold value.

9. The method of claim 6, wherein the video sampling rate is adjusted when the system idle is above a certain threshold value.

10. The method of claim 6, wherein the video sampling rate is adjusted when the system idle is below a certain threshold value.

11. A computer readable medium that stores a computer program for adjusting a video sampling rate that is used during a video encoding operation, the computer program comprising sets of instructions for:

a) receiving a metric that quantifies the usage of a computer that performs the video encoding operation;

b) computing an adjustment factor based on the metric; and

c) defining the video sampling rate based on the adjustment factor.

12. The computer readable medium of claim 11, wherein the set of instructions for computing of the adjustment factor comprises a set of instructions for using a proportional integral derivative (“

PID”

) operation to compute the adjustment factor based on the received metric.

13. The computer readable medium of claim 12, wherein the PID operation performs a proportional calculation, an integral calculation, and a derivative calculation, and combines results of said calculations through a set of weighting factors.

14. The computer readable medium of claim 13, wherein one or more of the weighting factors can be set to zero.

15. The computer readable medium of claim 11, wherein the set of instructions for computing of the adjustment factor comprises a set of instructions for using a non-linear calculation to compute the adjustment factor based on the received metric.

16. The computer readable medium of claim 11, wherein the metric comprises a system idle of the computer.

17. The computer readable medium of claim 16, wherein the system idle is an idle percentage of a processor of the computer.

18. The computer readable medium of claim 16, wherein the video sampling rate is not adjusted when the system idle is above a certain threshold value.

19. The computer readable medium of claim 16, wherein the video sampling rate is adjusted when the system idle is above a certain threshold value.

20. The computer readable medium of claim 16, wherein the video sampling rate is adjusted when the system idle is below a certain threshold value.