[ lour_component Il cy Il CX I specifies a filter coefficient or an element of a cross-correlation matrix between original and decoded signal with 16-bit precision. The value of filter_hint[ colour_component ][ cy ][ CX ] shall be in the range of -231 + 1 to 231 1, inclusive. colour_component specifies the related colour component. cy represents a counter in vertical direction, CX represents a counter in horizontal direction. Depending on filter_hint_type, the following applies: If filter hint type is equal to 0, the coefficients of a 2-dimensional FIR filter with the size of filter_hint_size_y filter_hint_size_x aretransmitted. Otherwise, if filter_hint_type is equal to 1, the filter coefficients of two 1-dimensional FIR filters are transmitted. In this case, filter_hint_size_y shall be equal to 2. The index cy = 0 specifies the filter coefficients of the horizontal filter and cy = 1 specifies the filter coefficients of the vertical filter. In the filtering process, the horizontal filter shall be applied first and the result shall be filtered by the vertical filter. Otherwise (filter_hint_type is equal to 2), the transmitted hints specify a cross-correlation matrix between the original signal S and the decoded signal s'. NOTE 1 - The normalized cross-correlation matrix for a related colour component with the size of filter_hint_size_y filter_hint_size_x is defined as follows: offset (D-27) where S denotes the original frame, s' denotes the decoded frame, h denotes the vertical height of the related colour component, w denotes the horizontal width of the related colour component, bitDepth denotes the bit depth of the colour component, offset is equal to (filter_hint_size_y 1), offset is equal to (filter_hint_size_x >> 1), 0 <= cy < filter_hint_size_y and 0 <= CX < filter_hint_size_x. NOTE 2 - A decoder can derive a Wiener post-filter from the cross-correlation matrix of original and decoded signal and the auto-correlation matrix of the decoded signal. additional_extension_flage equal to 0 indicates that no additi