Efficient systems and methods for transmitting compressed video data having different resolutions

• US 7,197,070 B1
• Filed: 06/04/2001
• Issued: 03/27/2007
• Est. Priority Date: 06/04/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Zhang, Ji, Liu, Humphrey
• Primary Examiner(s): DIEP, NHON THANH
• Application Number:
  US09/874,467
• Time in Patent Office: 2,122 Days
• Field of Search: None
• US Class Current: 375/240.01
• CPC Class Codes: H04B 1/66 for reducing bandwidth of signals; for improving efficiency of transmission H04B1/68 takes precedence
• CPC Class Codes: H04N 19/39 involving multiple description coding [MDC], i.e. with separate layers being structured as independently decodable descriptions of input picture data
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 21/234363 by altering the spatial resolution, e.g. for clients with a lower screen resolution
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities

Abstract

The present invention relates to systems and methods for combining compressed video data encoded or received with different resolutions. The present invention combines the compressed video data from the two separate bitstreams without decoding and re-encoding each bitstream. To do so, the present invention determines which compressed video bitstream has video data with a lower resolution, and applies a tiling process that alters the low resolution compressed video data such that it may be displayed at a high resolution.

Claims

1. A method for transmitting a bitstream comprising compressed video data, the method comprising:

receiving first compressed video data at a low resolution;

receiving second compressed video data at a high resolution;

determining the size of a low resolution border around a set of macroblocks included in a frame of the first compressed video data;

generating additional compressed video data displayable at the high resolution;

tiling macroblocks from the first compressed video data and macroblocks from the additional compressed video data; and

combining tiled first compressed video data and the second compressed video data into an output compressed bitstream including compressed video data that is displayable at the high resolution.

2. The method of claim 1 wherein the additional video data includes static video data macroblocks.

3. The method of claim 1 wherein macroblocks from the first compressed video data are tiled within the low resolution border and the additional compressed video data macroblocks are tiled outside the low resolution border.

4. The method of claim 1 further including inserting pan-and-scan information into the compressed bitstream.

5. The method of claim 1, wherein the bitstream comprises MPEG-1, MPEG-2 or MPEG-4 compressed video data.

6. The method of claim 1, wherein determining the size of a low resolution border around a set of macroblocks included in a frame of the first compressed video data, generating additional compressed video data displayable at the high resolution, and tiling macroblocks from the first compressed video data and macrobiotics from the additional compressed video data are performed in real time.

7. The method of claim 1, further comprising transcoding the output compressed bitstream.

8. The method of claim 1, wherein combining the tiled first compressed video data and the second compressed video data into the output compressed bitstream includes splicing the tiled first compressed video data and the second compressed video data or includes remultiplexing the tiled first compressed video data and the second compressed video data.

9. A system for transmitting a bitstream comprising compressed video data, the system comprising:

means for receiving first compressed video data at a low resolution;

means for receiving second compressed video data at a high resolution;

means for determining the size of a low resolution border around a set of macroblocks included in a frame of the first compressed video data;

means for generating additional compressed video data displayable at the high resolution;

means for tiling macroblocks from the first compressed video data and macroblocks from the additional compressed video data; and

means for combining tiled first compressed video data and the second compressed video data into an output compressed bitstream including compressed video data that is displayable at the high resolution.

10. A system as recited in claim 9, wherein the additional compressed video data includes static video data macroblocks.

11. A system as recited in claim 9, wherein the means for tiling macroblocks is configured to tile the macroblocks from the first compressed video data within the low resolution border and to tile the the additional compressed video data macroblocks outside the low resolution border.

12. A system as recited in claim 9, further comprising means for inserting pan-and-scan information into the compressed bitstream.

13. A system as recited in claim 9, wherein the bitstream comprises MPEG-1, MPEG-2 or MPEG-4 compressed video data.

14. A system as recited in claim 9, further comprising means for transcoding the output compressed bitstream.

15. A system as recited in claim 9, wherein the means for combining the tiled first compressed video data and the second compressed video data into the output compressed bitstream includes means for splicing the tiled first compressed video data and the second compressed video data, or includes means for remultiplexing the tiled first compressed video data and the second compressed video data.

16. Software tangibly embodied in a computer readable media and including instructions comprising:

instructions for receiving first compressed video data at a low resolution;

instructions for receiving second compressed video data at a high resolution;

instructions for determining the size of a low resolution border around a set of macroblocks included in a frame of the first compressed video data;

instructions for generating additional compressed video data displayable at the high resolution;

instructions for tiling macroblocks from the first compressed video data and macroblocks from the additional compressed video data; and

instructions for combining tiled first compressed video data and the second compressed video data into an output compressed bitstream including compressed video data that is displayable at the high resolution.

17. Software as recited in claim 16, wherein the additional compressed video data includes static video data macroblocks.

18. Software as recited in claim 16, wherein macroblocks from the first compressed video data are tiled within the low resolution border and the additional compressed video data macroblocks are tiled outside the low resolution border.

19. Software as recited in claim 16, further comprising instructions for inserting pan-and-scan information into the compressed bitstream.

20. Software as recited in claim 16, wherein the bitstream comprises MPEG-1, MPEG-2 or MPEG-4 compressed video data.

21. Software as recited in claim 16, further comprising instructions for determining the size of a low resolution border, generating additional compressed video data, and tiling macroblocks from the first compressed video data and macroblocks from the additional compressed video data in real time.

22. Software as recited in claim 16, further comprising instructions for transcoding the output compressed bitstream.