Arrangement and method for generating CP images

• US 7,720,157 B2
• Filed: 02/11/2005
• Issued: 05/18/2010
• Est. Priority Date: 02/13/2004
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Tandberg Telecom AS (Cisco Systems, Inc.)
• Inventors: Lia, Tom Erik, Johansen, Tom-Ivar
• Primary Examiner(s): WONG, ALLEN C
• Application Number:
  US11/055,176
• Publication Number:
  US 20050195275A1
• Time in Patent Office: 1,922 Days
• Field of Search: 375/240, 375/240.01, 375/240.02, 375/240.12, 375/240.24, 348/14.09, 382/238
• US Class Current: 375/240.24
• CPC Class Codes: H04N 7/152 Multipoint control units therefor
• CPC Class Codes: H04N 7/157 defining a virtual conference space and using avatars or agents computer conference optimisation or adaptation H04L12/1827

Abstract

A method for creating a coded target Continuous Presence (CP) image according to a video coding standard from a number of coded video signals including defined orders of macroblocks, each including coded video signals corresponding to a respective endpoint video image, received from endpoints participating in a multipoint video conference, the method including: decoding the coded video signals with plural decoders to generate decoded video signals; spatially mixing the decoded video signals, resulting in a number of CP images including regions respectively associated with each of the endpoint video images with a mixing unit; encoding the CP images with plural encoders; and rearranging macroblocks of the encoded CP images to create the target coded CP image with one or more re-packer units.

Claims

1. A method for creating a coded target Continuous Presence (CP) image according to a video coding standard from a plurality of coded video signals including defined orders of macroblocks, each comprising coded video signals corresponding to a respective endpoint video image, received from endpoints participating in a multipoint video conference,

said method comprising:

decoding said coded video signals with plural decoders to generate decoded video signals;

spatially mixing said decoded video signals, resulting in a plurality of CP images including regions respectively associated with each of said endpoint video images with a mixing unit;

encoding said plurality of CP images with plural encoders to generate at least a first coded CP image and a second coded CP image; and

rearranging and combining macroblocks from the first coded CP image and the second coded CP image to create said coded target CP image with one or more re-packer units, said coded target CP image including macroblocks from the first coded CP image and the second coded CP image.

2. The method according to claim 1, further comprising:

requesting the endpoints to code the respective endpoint video images according to the video standard and a certain resolution, bit rate and scaling.

3. The method according to claim 1, wherein said encoding said plurality of CP images comprises establishing defined orders of macroblocks corresponding to the video coding standard and a merging of region boundaries and macroblock boundaries.

4. The method according to claim 3, wherein the coded plurality of CP images and the coded target CP image each are of a CIF (Common Intermediate Format) format with 18 Group of Blocks (GOBs), each including 22 macroblocks, arranged in a stack formation so that the first 9 GOBs represent upper regions, and the last 9 GOBs represent lower regions.

5. The method according to claim 4, wherein the rearranging includes:

replacing m numbers of macroblocks representing a region width in n numbers of succeeding GOBs representing a region height in the first coded CP image with m numbers of macroblocks in n numbers of succeeding GOBs from the second coded CP image.

6. The method according to claim 5, wherein m=11, n=9, and said regions each represents one quadrant of a CP image.

7. The method according to claim 5, wherein m=7 or m=8, n=6 and said regions each represents one eighth of a CP image.

8. The method of claim 1, wherein a number of the plural encoders is less than a number of the plural decoders.

9. An apparatus in a Multipoint Control Unit (MCU) for creating a coded target continuous presence (CP) image according to a video coding standard from a plurality of coded video input signals, each corresponding to a respective endpoint video image, received from endpoints participating in a multipoint video conference, comprising:

a plurality of decoders configured to decode each of said coded video signals and to generate decoded video signals;

a mixing and scaling unit configured to mix said decoded video signals spatially, resulting in a plurality of CP images composed of regions respectively associated with each of said endpoint video images;

a plurality of encoders configured to encode said plurality of CP images to generate a least a first coded CP image and a second coded CP image; and

a re-packer configured to rearrange and combine macroblocks from the first coded CP image and the second coded CP image to create said target coded CP image, said target coded CP image including macroblocks from the first coded CP image and the second coded CP image.

10. The apparatus according to claim 9, wherein the coded plurality of CP images and the coded target CP image each are of a CIF (Common Intermediate Format) format with 18 Group of Blocks (GOBs), each including 22 macroblocks, arranged in a stack formation so that the first 9 GOBs represent upper regions, and the last 9 GOBs represent lower regions.

11. The apparatus according to claim 10, wherein the re-packer is further configured to replace m numbers of macroblocks representing a region width in n numbers of succeeding GOBs representing a region height in the first coded CP image with m numbers of macroblocks in n numbers of succeeding GOBs from the second coded CP image.

12. The apparatus according to claim 11, wherein m=11, n=9, and said regions each represents one quadrant of a CP image.

13. The apparatus according to claim 11, wherein m=7 or m=8, n=6, and said regions each represents one eighth of a CP image.

14. The apparatus of claim 9, wherein the number of encoders is less than the number of decoders.