DISPLAY MODE-BASED VIDEO ENCODING IN WIRELESS DISPLAY DEVICES

• US 20130128948A1
• Filed: 11/23/2011
• Published: 05/23/2013
• Est. Priority Date: 11/23/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rabii, Khosro M., Sethi, Sumeet Singh
• Granted Patent: US 9,277,230 B2
• Time in Patent Office: Days
• US Class Current: 375/240.01
• CPC Class Codes: H04L 65/764 at the destination reformatting of additional data in video clients H04N21/4355
• CPC Class Codes: H04N 19/114 Adapting the group of pictures [GOP] structure, e.g. number of B-frames between two anchor frames H04N19/107 takes precedence
• CPC Class Codes: H04N 19/12 Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/179 the unit being a scene or a shot
• CPC Class Codes: H04N 21/4122 additional display device, e.g. video projector digital output for controlling a plurality of local displays G06F3/1423
• CPC Class Codes: H04N 21/41265 having a remote control device for bidirectional communication between the remote control device and client device unidirectional remote control device H04N21/42204

Abstract

This disclosure relates to techniques for performing display mode based video encoding to reduce power consumption in a source device of a Wireless Display (WD) system. More specifically, the techniques enable the source device to select an encoding process based on whether the video data to be encoded is in a static display mode or a dynamic display mode. For example, when the video data is in the static display mode, the source device selects a static encoding process that reduces an amount of video data processing and compression, which in turn reduces power consumption at the source device. When the video data is in the dynamic mode, the source device may select a conventional dynamic encoding process. The source device encodes the video data according to the selected encoding process, and transmits the encoded video data to one or more sink devices in the WD system for display.

Claims

1. A method of encoding video data comprising:

determining, with a source device in a Wireless Display (WD) system, a display mode of video data to be encoded;

when the display mode of the video data comprises a dynamic mode, selecting a first encoding process for the video data;

when the display mode of the video data comprises a static mode, selecting a second encoding process for the video data different from the first encoding process, wherein the second encoding process reduces an amount of at least one of video data processing and compression; and

encoding the video data according to the selected encoding process.

2. The method of claim 1, further comprising transmitting the encoded video data to one or more sink devices in the WD system for display.

3. The method of claim 1, wherein determining a display mode of video data to be encoded comprises:

receiving content information regarding the video data prior to encoding;

when the content information indicates that the video data comprises static content over a period of time, determining that the display mode comprises the static mode; and

when the content information indicates that the video data comprises dynamic content over a period of time, determining that the display mode comprises the dynamic mode.

4. The method of claim 1, further comprising, when the second encoding process is selected, adjusting one or more video hierarchy values to reduce a number of intra-encoded video frames for the video data, wherein encoding the video data according to the second encoding process comprises intra-encoding video frames of the video data according to the adjusted video hierarchy values.

5. The method of claim 4, wherein adjusting video hierarchy values comprises adjusting one or more of a group of pictures (GOP) size, a video sequence start position, a picture type, and a slice type for the video data.

6. The method of claim 1, wherein encoding the video data according to the second encoding process comprises inter-encoding video frames of the video data as skip-mode frames without performing motion estimation.

7. The method of claim 6, further comprising eliminating retransmission of the skip-mode frames when an acknowledgement is not received from the sink devices.

8. The method of claim 1, wherein determining a display mode of video data to be encoded comprises determining a display mode for video data in each of two or more display segments.

9. The method of claim 8, further comprising, when the display mode of the video data in at least one of the display segments comprises the static mode, encoding the video data in the at least one of the display segments according to the second encoding process.

10. The method of claim 1, further comprising signaling the selected encoding process for the video data to the sink devices.

11. The method of claim 1, further comprising receiving, with the source device, status information from the one or more sink devices via an independent channel, and adjusting the selected encoding process for the video data based on the status information.

12. The method of claim 11, wherein receiving status information from the sink devices comprises receiving at least one of display capability profiles, display related adjustments, and display use status from the sink devices.

13. A source device in a Wireless Display (WD) system comprising:

a memory to store video data; and

a processor configured to determine a display mode of video data to be encoded, when the display mode of the video data comprises a dynamic mode, select a first encoding process for the video data, when the display mode of the video data comprises a static mode, select a second encoding process for the video data different from the first encoding process, wherein the second encoding process reduces an amount of at least one of video data processing and compression, and encode the video data according to the selected encoding process.

14. The source device of claim 13, further comprising a transmitter that transmits the encoded video data to one or more sink devices in the WD system for display.

15. The source device of claim 13, wherein the processor:

receives content information regarding the video data prior to encoding;

when the content information indicates that the video data comprises static content over a period of time, determines that the display mode comprises the static mode; and

when the content information indicates that the video data comprises dynamic content over a period of time, determines that the display mode comprises the dynamic mode.

16. The source device of claim 13, wherein, when the second encoding process is selected, the processor adjusts video hierarchy values to reduce a number of intra-encoded video frames for the video data, and intra-encodes video frames of the video data according to the adjusted video hierarchy values.

17. The source device of claim 16, wherein the processor adjusts video hierarchy values including one or more of a group of pictures (GOP) size, a video sequence start position, a picture type, and a slice type for the video data.

18. The source device of claim 13, wherein, when the second encoding process is selected, the processor inter-encodes video frames of the video data as skip-mode frames without performing motion estimation.

19. The source device of claim 18, wherein the processor eliminates retransmission of the skip-mode frames when an acknowledgement is not received from the sink devices.

20. The source device of claim 13, wherein the processor determines a display mode for video data in each of two or more display segments.

21. The source device of claim 20, wherein, when the display mode of the video data in at least one of the display segments comprises the static mode, the processor encodes the video data in the at least one of the display segments according to the second encoding process.

22. The source device of claim 13, wherein the processor signals the selected encoding process for the video data to the sink devices.

23. The source device of claim 13, wherein the processor receives status information from the one or more sink devices via an independent channel, and adjusts the selected encoding process for the video data based on the status information.

24. The source device of claim 23, wherein the processor receives at least one of display capability profiles, display related adjustments, and display use status from the sink devices.

25. A source device in a Wireless Display (WD) system comprising:

means for determining, with the source device, a display mode of video data to be encoded;

when the display mode of the video data comprises a dynamic mode, means for selecting a first encoding process for the video data;

when the display mode of the video data comprises a static mode, means for selecting a second encoding process for the video data different from the first encoding process, wherein the second encoding process reduces an amount of at least one of video data processing and compression; and

means for encoding the video data according to the selected encoding process.

26. The source device of claim 25, further comprising means for transmitting the encoded video data to one or more sink devices in the WD system for display.

27. The source device of claim 25, further comprising:

means for receiving content information regarding the video data prior to encoding;

when the content information indicates that the video data comprises static content over a period of time, means for determining that the display mode comprises the static mode; and

when the content information indicates that the video data comprises dynamic content over a period of time, means for determining that the display mode comprises the dynamic mode.

28. The source device of claim 25, further comprising, when the second encoding process is selected, means for adjusting video hierarchy values to reduce a number of intra-encoded video frames for the video data, and means for intra-encoding video frames of the video data according to the adjusted video hierarchy values.

29. The source device of claim 25, further comprising, when the second encoding process is selected, means for inter-encoding video frames of the video data as skip-mode frames without performing motion estimation.

30. The source device of claim 25, further comprising means for determining a display mode for video data in each of two or more display segments.

31. The source device of claim 25, further comprising means for signaling the selected encoding process for the video data to the sink devices.

32. The source device of claim 25, further comprising means for receiving, with the source device, status information from the one or more sink devices via an independent channel, and means for adjusting the selected encoding process for the video data based on the status information.

33. A computer-readable medium comprising instructions for encoding video data that cause one or more processor to:

determine, with a source device in a Wireless Display (WD) system, a display mode of video data to be encoded;

when the display mode of the video data comprises a dynamic mode, select a first encoding process for the video data;

when the display mode of the video data comprises a static mode, select a second encoding process for the video data different from the first encoding process, wherein the second encoding process reduces an amount of at least one of video data processing and compression; and

encode the video data according to the selected encoding process.

34. The computer-readable medium of claim 33, further comprising instructions that cause the processors to transmit the encoded video data to one or more sink devices in the WD system for display.

35. The computer-readable medium of claim 33, wherein the instructions cause the processors to:

receive content information regarding the video data prior to encoding;

when the content information indicates that the video data comprises static content over a period of time, determine that the display mode comprises the static mode; and

when the content information indicates that the video data comprises dynamic content over a period of time, determine that the display mode comprises the dynamic mode.

36. The computer-readable medium of claim 33, further comprising, when the second encoding process is selected, instructions that cause the processors to adjust video hierarchy values to reduce a number of intra-encoded video frames for the video data, and intra-encode video frames of the video data according to the adjusted video hierarchy values.

37. The computer-readable medium of claim 33, wherein, when the second encoding process is selected, the instructions cause the processors to inter-encode video frames of the video data as skip-mode frames without performing motion estimation.

38. The computer-readable medium of claim 33, wherein the instructions cause the processor to determine a display mode for video data in each of two or more display segments.

39. The computer-readable medium of claim 33, further comprising instructions that cause the processors to signal the selected encoding process for the video data to the sink devices.

40. The computer-readable medium of claim 33, further comprising instructions that cause the processors to receive, with the source device, status information from the one or more sink devices via an independent channel, and adjust the selected encoding process for the video data based on the status information.