A method for determining motion metadata for an encoded video, the method comprising: decoding frames of the encoded video, thereby deriving image frames; for some or all 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, and for each identified cell, determining a number of bordering cells for which the metric of change exceeds the change threshold, wherein a cell is bordering another cell if the cell is directly above, directly below, directly to the right, directly to the left, or directly diagonal, in any of the four different diagonal directions, of that cell; 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 bordering cells for which the metric of change exceeds the change threshold. decoding frames of the encoded video, thereby deriving image frames; for some or all 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, and for each identified cell, determining a number of bordering cells for which the metric of change exceeds the change threshold, wherein a cell is bordering another cell if the cell is directly above, directly below, directly to the right, directly to the left, or directly diagonal, in any of the four different diagonal directions, of that cell; 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 bordering cells for which the metric of change exceeds the change threshold. 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, and for each identified cell, determining a number of bordering cells for which the metric of change exceeds the change threshold, wherein a cell is bordering another cell if the cell is directly above, directly below, directly to the right, directly to the left, or directly diagonal, in any of the four different diagonal directions, of that cell; and 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, and for each identified cell, determining a number of bordering cells for which the metric of change exceeds the change threshold, wherein a cell is bordering another cell if the cell is directly above, directly below, directly to the right, directly to the left, or directly diagonal, in any of the four different diagonal directions, of that cell; 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 bordering cells for which the metric of change exceeds the change threshold.