VIDEO ENCODING SYSTEM AND METHOD

• US 20110268191A1
• Filed: 11/16/2009
• Published: 11/03/2011
• 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
• Granted Patent: US 8,731,060 B2
• Time in Patent Office: Days
• 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 of a video sequence, the encoding of a current image being done with respect to a previous and/or subsequent image, the encoding system including an input data reception module to receive the current image to be encoded and to receive a non estimated real motion vector of at least one moved area of the current image; a divider to divide the current image into macroblocks; an estimation 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; an allocating module to allocate the non estimated real motion vector to the macroblocks belonging to the moved area; a transmitting 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 the plurality of 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 and/or subsequent image (F_n-1) of said video sequence, said encoding system comprising:

an input data reception module configured to receive said current image (F_n) to be encoded, said input data reception module further configured to receive a non estimated real motion vector of at least one moved area of said current image (F_n);

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

an estimation module configured to estimate motion vectors depending on the macroblocks of said current image (F_n) and on said at least one previous and/or subsequent image (F_n-1);

a motion compensation module configured to receive motion vectors and to provide 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 module without any estimation of the motion vectors by said estimation module for said macroblocks belonging to said moved area.

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

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

a subtracter configured to carry out a difference between pixels of the current image (F_n) and the predicted area and to provide a residual error (D_n) corresponding to the difference,

a frequency transform module configured to apply a frequency transform on each macroblock processed by said estimation module and on said residual error (D_n),

a quantification module configured to quantify data from said frequency transform module,

an entropic encoder configured to encode data from said quantification module.

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 previous and/or 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 of at least one moved area of 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 previous and/or 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 at least one moved area of said current image being provided by a programming interface of a graphical environment of said server.

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 and/or subsequent image (F_n-1) of said video sequence, said encoding system comprising;

an input data reception module configured to receive said current image (F_n) to be encoded, said input data reception module further configured to receive a non estimated real motion vector of at least one moved area of said current image (F_n);

a divider configured to divide said current image (F_n) into a plurality of macroblocks;

an estimation module configured to estimate motion vectors depending on the macroblocks of said current image (F_n) and on said at least one previous and/or subsequent image (F_n-1);

a motion compensation module configured to receive motion vectors and to provide at least one predicted area;

an allocating module configured to allocate said non estimated real motion vector to the plurality of macroblocks belonging to said moved area;

a first transmitting module configured to transmit said non estimated real motion vector directly to said motion compensation module without any estimation of the motion vectors by said estimation module for said plurality of macroblocks belonging to said moved area.

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

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

a subtracter configured to early out a difference between pixels of the current image (F_n) and the predicted area and to provide a residual error (D_n) corresponding to said difference,

a frequency transform module configured to apply a frequency transform on each macroblock processed by said estimation module and on said residual error (D_n),

a quantification module configured to quantify data from said frequency transform module,

an entropic encoder configured to encode data from said quantification module.