Telefonaktiebolaget Lm Ericsson (Publ)

Christopher Hollmann

Jacob Ström

Per Wennersten

Davood Saffar

Rickard Sjöberg

Kenneth Andersson

Jonatan Samuelsson

Thomas Rusert

There is provided a method, performed by a temporal filter. The method comprises obtaining a current picture and a set of one or more neighbor pictures comprising a first neighbor picture, wherein each of the one or more neighbor pictures either precedes or follows the current picture in a picture count order. The method comprises, based on a first block of pixel values of the current picture and a first block of pixel values in the first neighbor picture, determining a first filter weight, W, for at least a first pixel value in the first block of pixel values of the current picture, wherein the first block of pixel values in the first neighbor picture correspond to the first block of pixel values in the current picture. The method comprises, calculating a first filtered pixel value, Pf, at least using as inputs to the calculation: W, P, and Pr, where PI is the first pixel value from the first block of pixel values of the current picture, and Pris a pixel value from the first neighbor picture that corresponds to the first pixel value.

Temporal filter

A method, decoder apparatus, and computer programs are provided. A bit stream having a video block encoded with a multiple transform selection (MTS) index is received. The MTS index is parsed to determine a value of it. Responsive to the MTS index value being a predetermined value (or one of a predetermined set of indices), a LFNST index is parsed from the bit stream to determine a value of it, the value providing an indication whether a LFNST transform set is to be used in decoding the video block. Responsive to the MTS index value not being the predetermined value (or one of the set of indices), the value of the LFNST index is set to a default value indicating no LFNST transform is to be used in the decoding. The video block is decoded based on the values of the MTS index and the LFNST index.

Method and apparatus for non-separable transform selection in an encoder and decoder

There are provided mechanisms for methods and apparatuses for transform selection in encoding and decoding of video blocks.

Method and apparatus for selecting transform selection in an encoder and decoder

There are provided mechanisms of guided transcoding. The methods are performed by a decoder, for producing original transform coefficients, and by an encoder, for producing coded delta transform coefficients. A decoding method comprises deriving a predicted residual block. The decoding method comprises transforming the predicted residual block using a forward transform, thereby producing a plurality of original estimated coefficients, the plurality of OECs comprising a first OEC. The decoding method comprises quantizing the plurality of OECs, thereby producing a plurality of quantized estimated transform coefficients comprising a first ETC corresponding to the first OEC. The decoding method comprises selecting a category based on the first OEC. The decoding method comprises decoding a first coded delta transform coefficient (DTC) corresponding to the first OEC, thereby producing a first decoded DTC, wherein the decoding comprises using the selected category to decode the first coded DTC. The decoding method comprises computing a first original transform coefficient by adding the first decoded DTC to the first ETC.

Decoding or encoding delta transform coefficients

There are provided mechanisms for methods and apparatuses for transform selection in encoding and decoding.

Delta quantized coefficients of a pixel block in a picture in a first representation of a video sequence are encoded based on information derived from estimated quantized coefficients for the pixel block. The delta quantized coefficients represent a difference between actual quantized coefficients of the pixel block derived by encoding at least a portion of the picture in the first representation of the video sequence and the estimated quantized coefficients. The estimated quantized coefficients represent a difference between a reconstructed block of a corresponding picture in a second representation of the video sequence and a prediction block obtained based on intra mode information and/or inter motion information derived by encoding the picture in the first representation of the video sequence.

Growing community of inventors

Uppsala, Sweden

Christopher Hollmann