Split screen video in a multimedia communication system

• US 20060215765A1
• Filed: 03/25/2005
• Published: 09/28/2006
• Est. Priority Date: 03/25/2005
• Status: Active Grant

• Current Assignee: Ansen Chen, Anson Chen, Cherng-Daw Hwang
• Original Assignee: Anson Chen, Cherng-Daw Hwang
• Inventors: Wang, Steven, Hwang, Cherng-Daw, Li, Weiping
• Granted Patent: US 7,830,409 B2
• Time in Patent Office: Days
• US Class Current: 375/240.210
• CPC Class Codes: H04N 19/103 Selection of coding mode or of prediction mode
• CPC Class Codes: H04N 19/162 User input
• CPC Class Codes: H04N 19/164 Feedback from the receiver or from the transmission channel
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/48 using compressed domain processing techniques other than decoding, e.g. modification of transform coefficients, variable length coding [VLC] data or run-length data motion estimation in a transform domain H04N19/547; processing of decoded motion vectors H04N19/513
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 7/152 Multipoint control units therefor

Abstract

A method is described for encoding video. A video sequence is captured at a full frame resolution. Boundaries for an inner region are identified within frames of the video sequence. The video sequence is encoded at the full frame resolution into a bitstream. The bitstream includes a sub-bitstream which encodes for the inner region. Data is embedded within the bitstream. The data identifies the sub-bitstream within the bitstream. In one aspect, the data is a header specifying the inner region. In another aspect, the encoding estimates motion for pixels within the inner region based on pixels within the inner region.

Claims

1. A method for encoding video comprising:

capturing a video sequence at a full frame resolution;

identifying boundaries for an inner region within frames of the video sequence;

encoding the video sequence at the full frame resolution into a bitstream, the bitstream including a sub-bitstream encoding for the inner region;

embedding data within the bitstream, the data identifying the sub-bitstream within the bitstream.

2. The method of claim 1, wherein the data is a header, the header specifying the inner region.

3. The method of claim 2, wherein the header comprises information specifying a number of Group of Blocks (GOBs) to discard, a number of center GOBs to remain, a number of start bits within each of the center GOBs to discard, and a number of center bits within each GOB to remain.

4. The method of claim 2, wherein the inner region is capable of being decoded from only the header and the sub-bitstream portion of the bitstream.

5. An apparatus for encoding video comprising:

means for capturing a video sequence at a full frame resolution;

means for identifying boundaries for an inner region within frames of the video sequence;

means for encoding the video sequence at the full frame resolution into a bitstream, the bitstream including a sub-bitstream encoding for the inner region;

means for embedding data within the bitstream, the data identifying the sub-bitstream within the bitstream.

6. The apparatus of claim 5, wherein the data is a header, the header specifying the inner region.

7. The apparatus of claim 6, wherein the header comprises information specifying a number of Group of Blocks (GOBs) to discard, a number of center GOBs to remain, a number of start bits within each of the center GOBs to discard, and a number of center bits within each GOB to remain.

8. The apparatus of claim 6, wherein the inner region is capable of being decoded from only the header and the sub-bitstream portion of the bitstream.

9. A machine-readable medium having instructions to cause a machine to perform a machine-implemented method comprising:

capturing a video sequence at a full frame resolution;

identifying boundaries for an inner region within frames of the video sequence;

encoding the video sequence at the full frame resolution into a bitstream, the bitstream including a sub-bitstream encoding for the inner region;

embedding data within the bitstream, the data identifying the sub-bitstream within the bitstream.

10. The machine-readable medium of claim 9, wherein the data is a header, the header specifying the inner region.

11. The machine-readable medium of claim 10, wherein the header comprises information specifying a number of Group of Blocks (GOBs) to discard, a number of center GOBs to remain, a number of start bits within each of the center GOBs to discard, and a number of center bits within each GOB to remain.

12. The machine-readable medium of claim 10, wherein the inner region is capable of being decoded from only the header and the sub-bitstream portion of the bitstream.

13. A method comprising:

receiving an encoded bitstream, the bitstream encoding for a video sequence at a full frame resolution;

identifying a sub-bitstream within the bitstream, the sub-bitstream encoding for an inner region within frames of the video sequence, the inner region having a first resolution lower than the full frame resolution; and

discarding bits of the bitstream to obtain the sub-bitstream.

14. The method of claim 13, further comprising:

down-sampling the sub-bitstream to a second resolution, the second resolution being lower than the first resolution.

15. The method of claim 13, further comprising:

transmitting the sub-bitstream to a destination end point for display within a split screen window.

16. The method of claim 13, wherein identifying the sub-bitstream comprises reading a header embedded in the bitstream, the header specifying the inner region.

17. The method of claim 13, further comprising:

appending a number of bits to the sub-bitstream to byte-align center bits within the sub-bitstream, the center bits encoding for a portion of the inner region;

appending a header to the sub-bitstream, the header including a value indicating the number of appended bits; and

transmitting the sub-bitstream, the appended bits, and the header to a destination end point.

18. An apparatus comprising:

means for receiving an encoded bitstream, the bitstream encoding for a video sequence at a full frame resolution;

means for identifying a sub-bitstream within the bitstream, the sub-bitstream encoding for an inner region within frames of the video sequence, the inner region having a first resolution lower than the full frame resolution; and

means for discarding bits of the bitstream to obtain the sub-bitstream.

19. The apparatus of claim 18, further comprising:

means for down-sampling the sub-bitstream to a second resolution, the second resolution being lower than the first resolution.

20. The apparatus of claim 18, further comprising:

means for transmitting the sub-bitstream to a destination end point for display within a split screen window.

21. The apparatus of claim 18, wherein means for identifying the sub-bitstream comprises means for reading a header embedded in the bitstream, the header specifying the inner region.

22. The apparatus of claim 18, further comprising:

means for appending a number of bits to the sub-bitstream to byte-align center bits within the sub-bitstream, the center bits encoding for a portion of the inner region;

means for appending a header to the sub-bitstream, the header including a value indicating the number of appended bits; and

means for transmitting the sub-bitstream, the appended bits, and the header to a destination end point.

23. A machine-readable medium having instructions to cause a machine to perform a machine-implemented method comprising:

receiving an encoded bitstream, the bitstream encoding for a video sequence at a full frame resolution;

identifying a sub-bitstream within the bitstream, the sub-bitstream encoding for an inner region within frames of the video sequence, the inner region having a first resolution lower than the full frame resolution; and

discarding bits of the bitstream to obtain the sub-bitstream.

24. The machine-readable medium of claim 23, wherein the method further comprises:

down-sampling the sub-bitstream to a second resolution, the second resolution being lower than the first resolution.

25. The machine-readable medium of claim 23, wherein the method further comprises:

transmitting the sub-bitstream to a destination end point for display within a split screen window.

26. The machine-readable medium of claim 23, wherein identifying the sub-bitstream comprises reading a header embedded in the bitstream, the header specifying the inner region.

27. The machine-readable medium of claim 23, wherein the method further comprises:

appending a number of bits to the sub-bitstream to byte-align center bits within the sub-bitstream, the center bits encoding for a portion of the inner region;

appending a header to the sub-bitstream, the header including a value indicating the number of appended bits; and

transmitting the sub-bitstream, the appended bits, and the header to a destination end point.

28. A method comprising:

identifying a split screen layout, the split screen layout for presenting video sequences from a plurality of end points;

determining a capability of an end point, the capability including a first resolution for capturing a video sequence at the end point;

determining a second resolution for displaying the video sequence within the split screen layout;

determining whether cutting the video sequence from the first resolution to the second resolution is acceptable;

if the cutting is acceptable, instructing the end point to encode the video sequence into a bitstream at the first resolution, the bitstream including a sub-bitstream encoding for an inner region of the video sequence at the second resolution.

29. The method of claim 28, further comprising:

if the cutting is unacceptable, determining whether down-sampling the video sequence from the first resolution to the second resolution is acceptable;

if the down-sampling is unacceptable, instructing the end point to encode the video sequence into a bitstream at the first resolution, the bitstream including a sub-bitstream encoding for an inner region of the video sequence at an intermediate resolution, the intermediate resolution being between the first resolution and the second resolution.

30. The method of claim 29, further comprising:

receiving the bitstream including the sub-bitstream at the intermediate resolution;

extracting the sub-bitstream from the bitstream; and

down-sampling the sub-bitstream to the second resolution.

31. An apparatus comprising:

means for identifying a split screen layout, the split screen layout for presenting video sequences from a plurality of end points;

means for determining a capability of an end point, the capability including a first resolution for capturing a video sequence at the end point;

means for determining a second resolution for displaying the video sequence within the split screen layout;

means for determining whether cutting the video sequence from the first resolution to the second resolution is acceptable;

if the cutting is acceptable, means for instructing the end point to encode the video sequence into a bitstream at the first resolution, the bitstream including a sub-bitstream encoding for an inner region of the video sequence at the second resolution.

32. The apparatus of claim 31, further comprising:

if the cutting is unacceptable, means for determining whether down-sampling the video sequence from the first resolution to the second resolution is acceptable;

if the down-sampling is unacceptable, means for instructing the end point to encode the video sequence into a bitstream at the first resolution, the bitstream including a sub-bitstream encoding for an inner region of the video sequence at an intermediate resolution, the intermediate resolution being between the first resolution and the second resolution.

33. The apparatus of claim 32, further comprising:

means for receiving the bitstream including the sub-bitstream at the intermediate resolution;

means for extracting the sub-bitstream from the bitstream; and

down-sampling the sub-bitstream to the second resolution.

34. A machine-readable medium having instructions to cause a machine to perform a machine-implemented method comprising:

identifying a split screen layout, the split screen layout for presenting video sequences from a plurality of end points;

determining a capability of an end point, the capability including a first resolution for capturing a video sequence at the end point;

determining a second resolution for displaying the video sequence within the split screen layout;

determining whether cutting the video sequence from the first resolution to the second resolution is acceptable;

if the cutting is acceptable, instructing the end point to encode the video sequence into a bitstream at the first resolution, the bitstream including a sub-bitstream encoding for an inner region of the video sequence at the second resolution.

35. The machine-readable medium of claim 34, wherein the method further comprises:

if the cutting is unacceptable, determining whether down-sampling the video sequence from the first resolution to the second resolution is acceptable;

if the down-sampling is unacceptable, instructing the end point to encode the video sequence into a bitstream at the first resolution, the bitstream including a sub-bitstream encoding for an inner region of the video sequence at an intermediate resolution, the intermediate resolution being between the first resolution and the second resolution.

36. The machine-readable medium of claim 35, wherein the method further comprises:

receiving the bitstream including the sub-bitstream at the intermediate resolution;

extracting the sub-bitstream from the bitstream; and

down-sampling the sub-bitstream to the second resolution.

37. An apparatus comprising:

means for displaying a split screen window within a graphical user interface, the window including a plurality of regions, each region to display a video sequence received from one of a plurality of end points;

means for receiving a selection of a first region within the window;

means for receiving a command to drag the selected first region over a second region within the window;

means for receiving a command to drop the selected first region over the second region; and

means for, in response to receiving the command to drop the selected first region, switching positions of the first region and the second region within the window.