Video processing device and method for determining motion metadata for an encoded video

A non-transitory computer readable recording medium having recorded thereon program code, which when executed at a device having processing capabilities, is configured to cause the device to perform operations comprising:

• decoding frames of the encoded video, thereby deriving image frames;
• for at least some of the image frames:
• dividing a current image frame into a mesh of cells, each cell comprising multiple image pixels;
• determining a metric of change for each cell by:
• comparing pixel data of each cell with pixel data of a correspondingly positioned cell of a previous and/or subsequent image frame;
• identifying cells within the image frame for which the metric of change exceeds a change threshold;
• for each identified cell, determining a number of adjacent cells for which the metric of change exceeds the change threshold;
• and
• storing the metric of change for each cell as motion metadata related to the current image frame,
• wherein the motion metadata further comprises, for each identified cell, the number of adjacent cells for which the metric of change exceeds the change threshold;
• setting a first region of interest of a scene depicted by the encoded video;
• setting a first motion threshold;
• accessing the stored motion metadata;
• and
• identifying image frames for which the metric of change in at least one cell overlapping with the first region of interest exceeds the first motion threshold, thereby identifying motion within the first region of interest.

A method for determining motion metadata for an encoded video, the method comprising:

• decoding frames of the encoded video, thereby deriving image frames;
• for at least some of the image frames:
• dividing a current image frame into a mesh of cells, each cell comprising multiple image pixels;
• determining a metric of change for each cell by:
• comparing pixel data of each cell with pixel data of a correspondingly positioned cell of a previous and/or subsequent image frame;
• identifying cells within the current image frame for which the metric of change exceeds a change threshold;
• for each identified cell, determining a number of adjacent cells for which the metric of change exceeds the change threshold;
• and
• storing the metric of change for each cell as motion metadata related to the current image frame,
• wherein the motion metadata further comprises, for each identified cell, the number of adjacent cells for which the metric of change exceeds the change threshold.

A non-transitory computer readable recording medium having recorded thereon program code, which when executed at a device having processing capabilities, is configured to cause the device to perform operations comprising:

• decoding frames of the encoded video, thereby deriving image frames;
• for at least some of the image frames:
• dividing a current image frame into a mesh of cells, each cell comprising multiple image pixels;
• determining a metric of change for each cell by:
• comparing pixel data of each cell with pixel data of a correspondingly positioned cell of a previous and/or subsequent image frame;
• identifying cells within the current image frame for which the metric of change exceeds a change threshold;
• for each identified cell, determining a number of adjacent cells for which the metric of change exceeds the change threshold;
• and
• storing the metric of change for each cell as motion metadata related to the current image frame,
• wherein the motion metadata further comprises, for each identified cell, the number of adjacent cells for which the metric of change exceeds the change threshold.

A video processing device comprising:

• a decoder configured to decode frames of an encoded video into image frames;
• and
• a processing circuitry configured to execute a motion meta data deriving operation on image frames decoded by the decoder, wherein the motion meta data deriving operation comprises:
• a dividing function configured to divide a current image frame into a mesh of cells, wherein each cell comprises multiple image pixels;
• a comparison function configured to determine a metric of change for each cell by comparing pixel data of each cell with pixel data of a correspondingly positioned cell of a previous and/or subsequent image frame;
• a cell identification function configured to:
• identify cells within the current image frame for which the metric of change exceeds a change threshold, and
• for each identified, determine a number of adjacent cells for which the metric of change exceeds the change threshold;
• and
• a storing function configured to store the metric of change for each cell as the motion metadata related to the current image frame,
• wherein the cell identification function is further configured to add the determined number of adjacent cells for which the metric of change exceeds the change threshold as part of the motion metadata for the identified cell.