The present invention provides an apparatus for performing inverse quantization for multiple decoding standards, where the functional operations that comprise the inverse quantizer are modularly implemented and can be selectably performed. Each operation can be represented via a table entry in an associated memory area, with the functional operation being performed via reference to that table entry. Functional operations can be bypassed as needed if inverse quantization does not need to be performed on a set of data. Certain other processing operations can be performed between steps as needed to accommodate different coding standards. Macroblock data can be read from and written back to a common storage area, or a direct path is provided for writing the data directly to a subsequent inverse transform device.