Bi-Level and Full-Color Video Combination for Video Communication

• US 20090284650A1
• Filed: 04/10/2008
• Published: 11/19/2009
• Est. Priority Date: 05/23/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Li, Jiang, Yu, Keman, Li, Shipeng
• Granted Patent: US 7,912,090 B2
• Time in Patent Office: Days
• US Class Current: 348/390.100
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket

Abstract

Systems and methods for video communication are described. In one aspect, network bandwidth conditions are estimated. Bi-level or full-color video is then transmitted over the network at transmission bit rates that are controlled as a function of the estimated bandwidth conditions. To this end, network bandwidth capability is periodically probed to identify similar, additional, or decreased bandwidth capabilities as compared to the estimated bandwidth conditions. Decisions to hold, decrease, or increase the video transmission bit rate are made based on the estimated bandwidth conditions in view of the probing operations. When the transmission bit rate is increased or decreased, the transmission bit rate is calculated to target an upper or lower bit rate, both of which are indicated by the estimated bandwidth conditions. Bi-level video communication is switched to full-color video transmission, or vice versa, when the video transmission bit rate respectively reaches the upper bit rate or the lower bit rate.

Claims

1. A method to for video communication, the method comprising operations for:

estimating bandwidth conditions of a network to determine a suitable target bit rate at which to transmit bi-level and full-color video;

transmitting bi-level or full-color video over the network at a transmission bit rate, the transmission bit rate being a function of the bandwidth conditions;

periodically probing bandwidth capability of the network to identify similar, additional, or decreased bandwidth availability as compared to estimated bandwidth conditions, wherein periodically probing bandwidth capability of the network further comprises sending redundant data and bi-level or full-color video data across the network at the transmission bit rate;

responsive to the probing operation, holding, decreasing, or increasing the transmission bit rate, the increasing and decreasing operations respectively targeting an upper or lower bit rate indicated by the bandwidth conditions; and

switching from bi-level to full-color video transmission, or vice versa, as a function of when the transmission bit rate respectively reaches the upper bit rate or the lower bit rate.

2. A method as recited in claim 1, wherein the full-color video has a color depth of 24 bits.

3. A method as recited in claim 1, wherein estimating bandwidth conditions is a function of packet loss rate and data round-trip-time (RTT) determinations.

4. A method as recited in claim 1, wherein estimating bandwidth conditions consider a lower threshold of packet loss, an upper threshold to indicate congestion if damage done to video quality resulting from packet loss is substantially large, a maximum transmission bit rate that indicates when delay of video will not be easily perceived during video playback, and a loaded zone associated with a hold bit rate decision that is large enough to avoid frequent switching oscillations between bi-level to/from full-color video.

5. A method as recited in claim 1, wherein transmitting further comprises initially transmitting bi-color video.

6. A method as recited in claim 1, wherein estimating further comprises:

calculating a threshold band to indicate congested, loaded, and unloaded states of the network; and

mapping hold, decrease, and increase transmission bit rate decisions to corresponding ones of the congested, loaded, and unloaded states of the network.

7. A method as recited in claim 1, wherein periodically probing bandwidth capability of the network further comprises sending redundant data and bi-level or full-color video data across the network to determine any increase or decrease in bandwidth capability of the network.

8. A method as recited in claim 1 wherein the method further comprises:

identifying a consecutive number of probing operations that result in a decision to decrease the transmission bit rate; and

responsive to the identifying, stopping operations of periodically probing such that no redundant data is being transmitted across the network and such that the transmission bit rate is only associated with a bi-level or full-color video transmission bit rate.

9. A method as recited in claim 8, wherein the consecutive number of probing operations is two (2).

10. A computer-readable medium comprising computer-program instructions for video communication, the computer-program instructions being executable by a processor and comprising instructions for:

estimating bandwidth conditions of a network to estimate network states at which to transmit bi-level and full-color video;

transmitting bi-level or full-color video over the network at a transmission bit rate, the transmission bit rate being a function of the bandwidth conditions;

periodically probing bandwidth capability of the network to identify similar, additional, or decreased bandwidth availability as compared to estimated bandwidth conditions, wherein the instructions for periodically probing bandwidth capability of the network further comprise instructions for sending redundant data and bi-level or full-color video data across the network at the transmission bit rate;

responsive to the probing operation, holding, decreasing, or increasing the transmission bit rate, the increasing and decreasing operations respectively targeting an upper or lower bit rate indicated by the bandwidth conditions; and

switching from bi-level to full-color video transmission, or vice versa, as a function of when the transmission bit rate respectively reaches the upper bit rate or the lower bit rate.

11. A computer-readable medium as recited in claim 10, wherein the full-color video has a color depth of 24 bits.

12. A computer-readable medium as recited in claim 10, wherein the instructions for estimating bandwidth conditions consider a lower threshold of packet loss, an upper threshold to indicate congestion if damage done to video quality resulting from packet loss is substantially large, a maximum transmission bit rate that indicates when delay of video will not be easily perceived during video playback, and a loaded zone associated with a hold bit rate decision that is large enough to avoid frequent switching oscillations between bi-level to/from full-color video.

13. A computer-readable medium as recited in claim 10, wherein the instructions for estimating bandwidth conditions further comprise instructions for determining bandwidth conditions as a function of packet loss rate and data round-trip-time (RTT) determinations.

14. A computer-readable medium as recited in claim 10, wherein the instructions for transmitting further comprise instructions for initially transmitting bi-color video.

15. A computer-readable medium as recited in claim 10, wherein the instructions for estimating further comprise instructions for:

calculating a threshold band to indicate congested, loaded, and unloaded states of the network; and

mapping hold, decrease, and increase transmission bit rate decisions to corresponding ones of the congested, loaded, and unloaded states of the network.

16. A computer-readable medium as recited in claim 10, wherein the instructions for periodically probing bandwidth capability of the network further comprises sending redundant data and bi-level or full-color video data across the network to determine any increase or decrease in bandwidth capability of the network.

17. A computer-readable medium as recited in claim 10 wherein the computer-program instructions further comprise instructions for:

identifying a consecutive number of probing operations that result in a decision to decrease the transmission bit rate; and

responsive to the identifying, stopping operations of periodically probing such that no redundant data is being transmitted across the network and such that the transmission bit rate is only associated with a bi-level or full-color video transmission bit rate.

18. A computer-readable medium as recited in claim 17, wherein the consecutive number of probing operations is two (2).

19. A computing device for video communication, the computing device comprising:

a processor; and

a memory coupled to the processor, the memory comprising computer-program instructions executable by the processor, the computer-program instructions comprising instructions for;

estimating bandwidth conditions of a network;

transmitting bi-level or full-color video over the network at a transmission bit rate, the transmission bit rate being a function of the bandwidth conditions;

periodically probing bandwidth capability of the network to identify similar, additional, or decreased bandwidth availability as compared to estimated bandwidth conditions, wherein the instructions for periodically probing bandwidth capability of the network further comprise instructions for sending redundant data and bi-level or full-color video data across the network at the transmission bit rate;

responsive to the probing operation, holding, decreasing, or increasing the transmission bit rate, the increasing and decreasing operations respectively targeting an upper or lower bit rate indicated by the bandwidth conditions; and

switching from bi-level to full-color video transmission, or vice versa, as a function of when the transmission bit rate respectively reaches the upper bit rate or the lower bit rate.

20. A computing device as recited in claim 19, wherein the full-color video has a color depth of 24 bits.

21. A computing device as recited in claim 19, wherein the instructions for estimating bandwidth conditions further comprise instructions for determining bandwidth conditions as a function of packet loss rate and data round-trip-time (RTT) determinations.

22. A computing device as recited in claim 19, wherein the instructions for transmitting further comprise instructions for initially transmitting bi-color video.

23. A computing device as recited in claim 19, wherein the instructions for estimating further comprise instructions for:

calculating a threshold band to indicate congested, loaded, and unloaded states of the network; and

mapping hold, decrease, and increase transmission bit rate decisions to corresponding ones of the congested, loaded, and unloaded states of the network.

24. A computing device as recited in claim 19, wherein the instructions for periodically probing bandwidth capability of the network further comprises sending redundant data and bi-level or full-color video data across the network to determine any increase or decrease in bandwidth capability of the network.

25. A computing device as recited in claim 19, wherein the computer-program instructions further comprise instructions for:

identifying a consecutive number of probing operations that result in a decision to decrease the transmission bit rate; and

responsive to the identifying, stopping operations of periodically probing such that no redundant data is being transmitted across the network and such that the transmission bit rate is only associated with a bi-level or full-color video transmission bit rate.

26. A computing device as recited in claim 25, wherein the consecutive number of probing operations is two (2).