Patent ID: 8824547

Claim:
A method of video coding, comprising: (a) obtaining a video sequence encoded at one or more initial constant bit-rates, the one or more initial constant bit-rates being in a range; (b) dividing the encoded video sequence into temporal portions; (c) analysing respective temporal portions whereby to determine, in respect of each of a plurality of said temporal portions, a constant bit-rate at which said temporal portion could be encoded to meet a predetermined perceptual quality requirement; (d) partitioning the range of constant bit-rates so-determined into a plurality of sub-ranges, each sub-range having a selected one of a plurality of different bit-rates associated therewith; (e) assigning respective temporal portions to one of said sub-ranges such that said temporal portions, if encoded at the bit-rate associated with the sub-range to which they are assigned, would meet said predetermined perceptual quality requirement; (f) establishing, in respect of said sequence, a first bit-count measure indicative of an amount of data that would be required for said temporal portions to be encoded respectively at the bit-rates of the sub-ranges to which they have been assigned, and a second bit-count measure indicative of an amount of data that would be required for said temporal portions each to be encoded at bit-rates sufficient to match a constant perceptual quality requirement; (g) determining a difference measure indicative of a level of disparity between said first bit-count measure and said second bit-count measure; (h) re-partitioning the range of constant bit-rates at least once using an updated set of bit-rates such that at least one sub-range has a different bit-rate associated therewith, said updated set of bit-rates being such that a subsequent performance of steps (e), (f) and (g) would result in determination of a difference measure indicative of a decrease in said disparity; and (i) creating an output video sequence comprising temporal portions respectively encoded at different bit-rates from said updated set of bit-rates.