Methods are provided for reducing the size of a transpose buffer used for computation of a two-dimensional (2D) separable transform. Scaling factors and clip bit widths determined for a particular transpose buffer size and the expected transform sizes are used to reduce the size of the intermediate results of applying the 2D separable transform. The reduced bit widths of the intermediate results may vary across the intermediate results. In some embodiments, the scaling factors and associated clip bit widths may be adapted during encoding.