A video decoder configured to: decode a video from a data stream using motion compensation prediction to predict current pictures from reference pictures based on motion vector differences transmitted in the data stream at half-sample resolution, with first reference pictures of equal picture resolution as respective current pictures for which they are used in prediction and second reference pictures of different picture resolution than respective current pictures for which they are used in prediction, and using interpolation filters (431, 432) to obtain sub-sample values within reference sample arrays formed from respective reference pictures, select an interpolation filter to obtain half-sample values within a reference sample array, the reference sample array formed from a reference picture by using a motion vector, the interpolation filter selected from a first interpolation filter version and a second interpolation filter version, wherein the first interpolation filter version is a 6 tap filter with coefficients 3,9,20,20,9,3 and the second interpolation filter version is an 8 tap filter with coefficients -1,4,-11,40,40,-11,4,-1, by selecting the first interpolation filter version for horizontal interpolation when the reference picture is equal in picture resolution to the current picture in horizontal dimension and selecting the second interpolation filter version for horizontal interpolation when the reference picture is unequal in picture resolution to the current picture in horizontal dimension, and/or selecting the first interpolation filter version for vertical interpolation when the reference picture is equal in picture resolution to the current picture in vertical dimension and selecting the second interpolation filter version for vertical interpolation when the reference picture is unequal in picture resolution to the current picture in vertical dimension. decode a video from a data stream using motion compensation prediction to predict current pictures from reference pictures based on motion vector differences transmitted in the data stream at half-sample resolution, with first reference pictures of equal picture resolution as respective current pictures for which they are used in prediction and second reference pictures of different picture resolution than respective current pictures for which they are used in prediction, and using interpolation filters (431, 432) to obtain sub-sample values within reference sample arrays formed from respective reference pictures, based on motion vector differences transmitted in the data stream at half-sample resolution, with first reference pictures of equal picture resolution as respective current pictures for which they are used in prediction and second reference pictures of different picture resolution than respective current pictures for which they are used in prediction, and using interpolation filters (431, 432) to obtain sub-sample values within reference sample arrays formed from respective reference pictures, select an interpolation filter to obtain half-sample values within a reference sample array, the reference sample array formed from a reference picture by using a motion vector, the interpolation filter selected from a first interpolation filter version and a second interpolation filter version, wherein the first interpolation filter version is a 6 tap filter with coefficients 3,9,20,20,9,3 and the second interpolation filter version is an 8 tap filter with coefficients -1,4,-11,40,40,-11,4,-1, by selecting the first interpolation filter version for horizontal interpolation when the reference picture is equal in picture resolution to the current picture in horizontal dimension and selecting the second interpolation filter version for horizontal interpolation when the reference picture is unequal in picture resolution to the current picture in horizontal dimension, and/or selecting the first interpolation filter version for vertical interpolation when the reference picture is equal in picture resolution to the current picture in vertical dimension and selecting the second interpolation filter version for vertical interpolation when the reference picture is unequal in picture resolution to the current picture in vertical dimension. selecting the first interpolation filter version for horizontal interpolation when the reference picture is equal in picture resolution to the current picture in horizontal dimension and selecting the second interpolation filter version for horizontal interpolation when the reference picture is unequal in picture resolution to the current picture in horizontal dimension, and/or selecting the first interpolation filter version for vertical interpolation when the reference picture is equal in picture resolution to the current picture in vertical dimension and selecting the second interpolation filter version for vertical interpolation when the reference picture is unequal in picture resolution to the current picture in vertical dimension.