Device and method for coding video data

• US 7,577,196 B2
• Filed: 07/02/2004
• Issued: 08/18/2009
• Est. Priority Date: 07/04/2003
• Status: Active Grant

• Current Assignee: Burley Licensing LLC (IP Edge LLC)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Ducloux, Xavier, Alexandre, Patrice, Noblet, Ludovic
• Primary Examiner(s): Banks Harold; Marsha D
• Assistant Examiner(s): Anyikire; Chikaodili E
• Application Number:
  US10/884,158
• Publication Number:
  US 20050117644A1
• Time in Patent Office: 1,873 Days
• Field of Search: 375/240.01, 37524012-24017, 375 12- 17
• US Class Current: 375/240.01
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/112 according to a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 19/114 Adapting the group of pictures [GOP] structure, e.g. number of B-frames between two anchor frames H04N19/107 takes precedence
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/147 according to rate distortion criteria rate-distortion as a criterion for motion estimation H04N19/567
• CPC Class Codes: H04N 19/149 by estimating the code amount by means of a model, e.g. mathematical model or statistical model
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/177 the unit being a group of pictures [GOP]
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

The invention relates to a device for coding video frame sequences, comprising

• • means (1) for measuring the spatial activity of the video frames to be coded,
  • means (1) for measuring the temporal activity of the video frames to be coded,
  • means (2) for coding the frames as a frame structure or as a field structure.

According to the invention, the means (2) for coding the frames as a frame structure or as a field structure are able to choose the field or frame structure dynamically as a function of the measurements of spatial and temporal activity of the said frame.

Claims

1. Device for coding video frame sequences, comprising

first means for measuring the spatial activity of the video frames to be coded,

second means for measuring the temporal activity of the video frames to be coded,

means for coding the frames as a frame structure or as a field structure, said coding means being able to choose the one of the field or frame structure dynamically as a function of a quotient between the measurements of spatial and temporal activity means for determining whether the video sequences are of interlaced type or of progressive type on the basis of the measurements of spatial and temporal activity wherein, each frame comprising a first field interlaced with a second field;

the first measuring means are adapted for measuring the spatial activity of the first field of a frame and representing the same by a first value, and for measuring the spatial activity of the second field of said frame and representing the same by a second value;

the second measuring means are adapted for measuring the temporal activity between the first and second fields of said frame and representing the same by a third value;

and for measuring the temporal activity between the first field of said frame and the second field of a previous frame and representing the same by fourth value; and

the coding means are adapted to compute a weighted temporal activity as follows;

2. Device according to claim 1, wherein the coding means chooses a field structure:

1) when an interlaced sequence is determined for said frame and for said previous frame; and

     2) when the weighted temporal activity is greater than a predefined threshold;

said coding means choosing a frame structure when either criteria 1 or 2 are not met.

3. Device, according to claim 1 wherein said determining means determine that said frame belongs to a progressive sequence if 0.9 multiplied by the sum of said first and second values is greater than a predetermined threshold.

4. Device according to claim 3, wherein said predetermined threshold equals the third value.