A signal processor (100; 1010; 1020) for providing a processed version (112; s 1 '(n); Q 1 '(n)) of an input signal in dependence on the input signal (110; s 1 (n); q 1 (n)), wherein the input signal is an audio signal or a video signal, the signal processor comprising: a windower (120; 1014; 1024), configured to window a portion of the input signal, or of a pre-processed version thereof, in dependence on a signal processing window described by signal processing window values (w(n); w 1 (n)) for a plurality of window value index values (n) in order to obtain the processed version of the input signal; and a window provider (130; 603, 604, 605, 606; 609, 605, 606) for providing the signal processing window values for the plurality of window value index values in dependence on one or more window shape parameters (132; a 1), wherein the window provider is configured to evaluate a sine function for a plurality of argument values (c'(n)) associated with the window value index values (n), to obtain the signal processing window values (w(n)); wherein the window provider is configured to compute a weighted sum of a linear term (c(n)), which is linearly dependent on the window value index values (n), and function values of one or more shaping functions, which one or more shaping functions map the window value index values (n) onto the corresponding function values and which one or more shaping functions are point-symmetric with respect to a center of a window slope, to obtain the argument values; wherein the characteristics of the window defined by the signal processing window values are adjusted by modifying the weighting of the one or more shaping functions in dependence on the one or more window shape parameters, such that windows of different characteristics are obtainable. a windower (120; 1014; 1024), configured to window a portion of the input signal, or of a pre-processed version thereof, in dependence on a signal processing window described by signal processing window values (w(n); w 1 (n)) for a plurality of window value index values (n) in order to obtain the processed version of the input signal; and a window provider (130; 603, 604, 605, 606; 609, 605, 606) for providing the signal processing window values for the plurality of window value index values in dependence on one or more window shape parameters (132; a 1), wherein the window provider is configured to evaluate a sine function for a plurality of argument values (c'(n)) associated with the window value index values (n), to obtain the signal processing window values (w(n)); wherein the window provider is configured to compute a weighted sum of a linear term (c(n)), which is linearly dependent on the window value index values (n), and function values of one or more shaping functions, which one or more shaping functions map the window value index values (n) onto the corresponding function values and which one or more shaping functions are point-symmetric with respect to a center of a window slope, to obtain the argument values; wherein the characteristics of the window defined by the signal processing window values are adjusted by modifying the weighting of the one or more shaping functions in dependence on the one or more window shape parameters, such that windows of different characteristics are obtainable.