Abstract: In video coding, where differences between input picture values and picture prediction values are transformed in a block based transform, the differences are formed in a series of parallel steps. A first step conducted in parallel upon a first subset of pixels uses prediction values based wholly on previously processed blocks. This first subset can include anchor pixels which are not contiguous with any previously processed block. A second step conducted in parallel upon a second subset includes pixels which are predicted from pixels of the first subset.

Abstract: In video coding or decoding, coding blocks in a current frame are predicted from blocks in previously encoded frames with prediction samples and associated information organised in a prediction unit. A decision on which prediction unit type to consider for coding is made upon analysis of the distribution of a sum of absolute difference or other function of the residual signal over the block.

Abstract: In video encoding, where image values are transformed to provide transform coefficients and transform coefficients are quantised to derive a compressed bitstream, an ID profile is selected at the encoder and used with a representative image intensity to scale image values in the block. The selected ID profile is signalled to the decoder with the compressed bitstream. At the decoder, the ID profile is extracted from the compressed bitstream and—after performing inverse quantisation and an inverse transform to form image values—those image values are inverse scaled.

Abstract: Video encoding or decoding utilizing a spatial transform operating on rows and columns of a block, with a set of transform skip modes including: transform on rows and columns; transform on rows only; transform on columns only; no transform. An indication of the selected mode is provided to the decoder. Coefficients are scaled by a factor dependent upon the norm of the transform vector of the skipped transform to bring the untransformed image values to the same level as transformed coefficients.

Abstract: In video encoding, a video input received in 4:2:2 is resampled. Residuals are formed through the use of reference samples stored in the native 4:2:2, before transforming, quantising and entropy coding to form an encoded bitstream in the resampled format. The encoded bitstream contains a message indicating chrominance resampling and a selected chrominance resampling filter for the decoder to use. An encoder may have a first mode in which the 4:2:2 is up-sampled to 4:4:4 and a second mode in which the 4:2:2 is down-sampled to 4:2:0.

Abstract: Video encoding or decoding utilising a spatial transform operating on rows and columns of a block, with a set of transform skip modes including: transform on rows and columns; transform on rows only; transform on columns only; no transform. An indication of the selected mode is provided to the decoder. Coefficients are scaled by a factor dependent upon the norm of the transform vector of the skipped transform to bring the untransformed image values to the same level as transformed coefficients.

Abstract: In video coding, where differences between input picture values and picture prediction values are transformed in a block based transform, the differences are formed in a series of parallel steps. A first step conducted in parallel upon a first subset of pixels uses prediction values based wholly on previously processed blocks. This first subset can include anchor pixels which are not contiguous with any previously processed block. A second step conducted in parallel upon a second subset includes pixels which are predicted from pixels of the first subset.