Video encoding system and method

• US 8,731,060 B2
• Filed: 11/16/2009
• Issued: 05/20/2014
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: Sagemcom Broadband SAS (Sagemcom Holding SAS)
• Original Assignee: Sagemcom Broadband SAS (Sagemcom Holding SAS)
• Inventors: Morard, Jean-Pierre
• Primary Examiner(s): Rao, Andy
• Assistant Examiner(s): ELAHI, SHAN E
• Application Number:
  US13/142,551
• Publication Number:
  US 20110268191A1
• Time in Patent Office: 1,646 Days
• Field of Search: 375/240.16, 375/240.01
• US Class Current: 375/240.16
• 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 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams

Abstract

A video encoding system for encoding consecutive images, the encoding of a current image being done with respect to a previous and/or subsequent image, the encoding system including a reception module to receive the current image to be encoded and to receive a non-estimated real motion vector of a moved area of the current image; a divider to divide the current image into macroblocks; a module to estimate motion vectors depending on the macroblocks of the current image and on the previous and/or subsequent image; a motion compensation module to receive motion vectors and to provide a predicted area; a module to allocate the non-estimated real motion vector to the macroblocks belonging to the moved area; a module to transmit the non-estimated real motion vector directly to the motion compensation module without any estimation of the motion vectors by the estimation module for macroblocks belonging to the moved area.

Claims

1. A video encoding system for encoding consecutive images of a video sequence, the encoding of at least one current image (F_n) being operated with respect to at least one previous image or at least one subsequent image, or both at least one previous image and at least one subsequent image, (F_n-1) of said video sequence, said encoding system comprising one or more electronic circuits including:

an input data reception means for receiving said current image (F_n) to be encoded and a non estimated real motion vector that is representative of an area of said current image that has moved within said current image (F_n);

means for dividing said current image (F_n) into macroblocks;

a data estimation means for estimating motion vectors depending on the macroblocks of said current image (F_n) and on said at least one previous image or said at least one subsequent image, or both said at least one previous image and said at least one subsequent image, (F_n-1);

a motion compensation means for receiving motion vectors and for providing at least one predicted area;

means for allocating said non estimated real motion vector to the macroblocks belonging to said moved area;

means for transmitting said non estimated real motion vector directly to said motion compensation means without any estimation of the motion vectors by said data estimation means for said macroblocks belonging to said moved area, and

a subtractor means for determining a difference between pixels of the current image (F_n) and the predicted area and for providing a residual error (D_n) corresponding to said determined difference.

2. The video encoding system according to claim 1, comprising means for only transmitting the macroblocks not belonging to said moved area to said data estimation means.

3. The video encoding system according to claim 1, comprising:

a frequency transform means for applying a frequency transform on each macroblock processed by said data estimation means and on said residual error (D_n),

a quantification means for quantifying data from said frequency transform means,

an entropic encoder means for encoding data from said quantification means.

4. A video encoding method for encoding consecutive images of a video sequence, the encoding of at least one current image (F_n) being operated with respect to at least one image or at least one subsequent image, or both at least one previous image and at least one subsequent image, (F_n-1) of said video sequence, said method comprising:

receiving said current image (F_n) to be encoded and a non estimated real motion vector that is representative of an area of said current image that has moved within said current image (F_n);

dividing said current image into macroblocks;

allocating said non estimated real motion vector to the macroblocks belonging to said moved area;

estimating motion vectors depending on the macroblocks of said current image and of said at least one image or said at least one subsequent image, or both said at least one previous image and at least one subsequent image, said estimation being made only from the macroblocks not belonging to said moved area,

said current image to be encoded being transmitted from a server to a client terminal, the encoding being carried out at the server and said non estimated real vector of the moved area of said current image being provided by a programming interface of a graphical environment of said server;

providing a predicted area using the estimated motion vectors and the non estimated real motion vector, and

determining a difference between pixels of the current image (F_n) and the predicted area and providing a residual error (D_n) corresponding to said determined difference.

5. The method according to claim 4, wherein the screen of said server is displayed by said client terminal on a screen according to a Remote Frame Buffer (RFB) protocol.

6. The method according to claim 4 wherein said video encoding is a space-time encoding H264.

7. The method according to claim 4, wherein said real motion vector of said moved area is determined in the following cases:

horizontal or vertical scrolling of said moved area with a browser type application;

displacement of a graphical window of the operating system of said server;

transition from a slide to another in the case of a slideshow;

flash type animation.

8. The method according to claim 4, wherein said client terminal is a video decoder.

9. The method according to claim 4, wherein said current image and said real motion vector are initially encoded in an RGB format then undergo a YUV format transformation.

10. The method according to claim 4, wherein said real motion vector is a two- or three-dimensional vector.

11. The method according to claim 5, wherein the Remote Frame Buffer (RFB) protocol is a Virtual Network Computing (VNC) protocol.

12. A video encoding system for encoding consecutive images of a video sequence, the encoding of at least one current image (F_n) being done with respect to at least one previous image or at least one subsequent image, or both at least one previous image and at least one subsequent image, (F_n-1) of said video sequence, said encoding system comprising one or more electronic circuits including:

an input data reception means for receiving said current image (F_n) to be encoded and a non estimated real motion vector that is representative of an area of said current image that has moved within said current image (F_n);

a divider means for dividing said current image (F_n) into a plurality of macroblocks;

a data estimation means for estimating motion vectors depending on the macroblocks of said current image (F_n) and on said at least one previous image or said at least one subsequent image, or both at least one previous image and at least one subsequent image, (F_n-1);

a motion compensation means for receiving motion vectors and for providing at least one predicted area;

an allocating means for allocating said non estimated real motion vector to the plurality of macroblocks belonging to said moved area;

a first transmitting means for transmitting said non estimated real motion vector directly to said motion compensation means without any estimation of the motion vectors by said estimation means for said plurality of macroblocks belonging to said moved area, and

a subtractor means for determining a difference between pixels of the current image (F_n) and the predicted area and for providing a residual error (D_n) corresponding to said determined difference.

13. A video encoding system according to claim 12, comprising a second transmitting means for only transmitting the plurality of macroblocks not belonging to said moved area to said data estimation means.

14. A video encoding system according to claim 12, comprising:

a frequency transform means for applying a frequency transform on each macroblock processed by said data estimation means and on said residual error (D_n),

a quantification means for quantifying data from said frequency transform means,

an entropic encoder means for encoding data from said quantification means.

15. A video encoding system according to claim 12, wherein the motion compensation means is in direct communication with both the data estimation means and the first transmitting means so as to directly receive from said estimation means the estimated motion vector and to directly receive from the first transmitting means the non estimated real motion vector.