A disclosed method may include storing, within a hardware memory device included as part of a rate—distortion optimization (RDO) hardware pipeline, at least one transform unit table that (1) is pregenerated from a seed probability table for transformation of video data in accordance with a video encoding standard, (2) corresponds to a transform operation supported by the video encoding standard, and (3) corresponds to a transform unit included in the RDO hardware pipeline. The method may also include determining, by accessing the transform unit table, an RDO token rate for an encoding of the video data by a hardware video encoding pipeline that includes the RDO hardware pipeline, and selecting, based on the RDO token rate, a transform operation for the encoding of the video data.

A disclosed method may include storing, within a hardware memory device included as part of a rate—distortion optimization (RDO) hardware pipeline, at least one transform unit table that (1) is pregenerated from a seed probability table for transformation of video data in accordance with a video encoding standard, (2) corresponds to a transform operation supported by the video encoding standard, and (3) corresponds to a transform unit included in the RDO hardware pipeline. The method may also include determining, by accessing the transform unit table, an RDO token rate for an encoding of the video data by a hardware video encoding pipeline that includes the RDO hardware pipeline, and selecting, based on the RDO token rate, a transform operation for the encoding of the video data.

A disclosed system may include a hardware distortion data pipeline that may include (1) a quantization module that generates a quantized data set, (2) an inverse quantization module that generates, from the quantized data set, an inverse quantized data set by executing an inverse quantization of the quantized data set, and (3) an inverse transformation module that generates an inversely transformed data set by executing an inverse transformation of the inverse quantized data set. The system may also include a hardware determination pipeline that determines a distortion metric based on the inversely transformed data set and the residual frame data set, and a hardware token rate pipeline that determines, based on the quantized data set, a token rate for an encoding of the residual frame data set via a video encoding pipeline. Various other methods, systems, and computer-readable media are also disclosed.

A disclosed system may include a hardware distortion data pipeline that may include (1) a quantization module that generates a quantized data set, (2) an inverse quantization module that generates, from the quantized data set, an inverse quantized data set by executing an inverse quantization of the quantized data set, and (3) an inverse transformation module that generates an inversely transformed data set by executing an inverse transformation of the inverse quantized data set. The system may also include a hardware determination pipeline that determines a distortion metric based on the inversely transformed data set and the residual frame data set, and a hardware token rate pipeline that determines, based on the quantized data set, a token rate for an encoding of the residual frame data set via a video encoding pipeline. Various other methods, systems, and computer-readable media are also disclosed.

An apparatus can include a prediction mode decoding module configured to derive a luma intra prediction mode and a chroma intra prediction mode; a prediction size determining module configured to determine a size of a luma transform unit and a size of a chroma transform unit using transform size information; a reference pixel generating module configured to generate referential pixels if at least one reference pixel is unavailable; a reference pixel filtering module configured to adaptively filter the reference pixels of a current luma block based on the luma intra prediction mode and the size of the luma transform unit, and not to filter the reference pixels of a current chroma block; a prediction block generating module configured to generate prediction blocks of the current luma block and the current chroma block; a residual bock generating module configured to generate a luma residual block and a chroma residual block; and an adder.

An apparatus can include a prediction mode decoding module configured to derive a luma intra prediction mode and a chroma intra prediction mode; a prediction size determining module configured to determine a size of a luma transform unit and a size of a chroma transform unit using transform size information; a reference pixel generating module configured to generate referential pixels if at least one reference pixel is unavailable; a reference pixel filtering module configured to adaptively filter the reference pixels of a current luma block based on the luma intra prediction mode and the size of the luma transform unit, and not to filter the reference pixels of a current chroma block; a prediction block generating module configured to generate prediction blocks of the current luma block and the current chroma block; a residual bock generating module configured to generate a luma residual block and a chroma residual block; and an adder.

A method of controlling residual coding for decoding or encoding of a video sequence, is performed by at least one processor and includes determining whether a small transform size of a primary transform is to be used for the residual coding of a coded block of the video sequence. The method further includes based on the small transform size of the primary transform being determined to be used, identifying, as the primary transform, a first transform set including discrete sine transform (DST)-4 and discrete cosine transform (DCT)-4, based on the small transform size of the primary transform being determined to not be used, identifying, as the primary transform, a second transform set including DST-7 and DCT-8, and performing the residual coding of the coded block, using the identified primary transform.

A method of controlling residual coding for decoding or encoding of a video sequence, is performed by at least one processor and includes determining whether a small transform size of a primary transform is to be used for the residual coding of a coded block of the video sequence. The method further includes based on the small transform size of the primary transform being determined to be used, identifying, as the primary transform, a first transform set including discrete sine transform (DST)-4 and discrete cosine transform (DCT)-4, based on the small transform size of the primary transform being determined to not be used, identifying, as the primary transform, a second transform set including DST-7 and DCT-8, and performing the residual coding of the coded block, using the identified primary transform.

Methods, systems, and devices for coefficient scaling for high-precision image and video coding are described. A example method of video processing includes performing a conversion between a current block of a video and a bitstream representation of the video according to a rule, wherein the rule specifies that the conversion includes during encoding, skipping applying a forward transform to residual coefficients of the current block prior to including in the bitstream representation, or during decoding, reconstructing residual coefficients of the current block from the bitstream representation without applying an inverse transform, and wherein the rule further specifies that a scale factor is applied to the residual coefficients independent of a size of the current block.

Methods, systems, and devices for coefficient scaling for high-precision image and video coding are described. A example method of video processing includes performing a conversion between a current block of a video and a bitstream representation of the video according to a rule, wherein the rule specifies that the conversion includes during encoding, skipping applying a forward transform to residual coefficients of the current block prior to including in the bitstream representation, or during decoding, reconstructing residual coefficients of the current block from the bitstream representation without applying an inverse transform, and wherein the rule further specifies that a scale factor is applied to the residual coefficients independent of a size of the current block.