Video decoder with reduced dynamic range transform with inverse transform shifting memory

A method for decoding video comprising:

• receiving quantized coefficients representative of a block of video representative of a plurality of pixels;
• descaling the quantized coefficients based on a quantization parameter, a coefficient index, and a transform size to generate descaled coefficients;
• applying an adjustment mechanism to the descaled coefficients to modify the descaled coefficients to generate modified descaled coefficients, wherein the adjustment mechanism is a variable based on the transform size;
• clipping the modified descaled coefficients to a predetermined bit depth to generate clipped coefficients;
• storing the clipped coefficients in a memory;
• and
• inverse transforming the clipped coefficients to output a decoded residue, wherein the inverse transforming comprises:
• one-dimension inverse transforming in a first direction the clipped coefficients to generate first direction inverse transformed coefficients;
• prior to one-dimension inverse transforming the first direction inverse transformed coefficients in a second direction, shifting the first direction inverse transformed coefficients right to generate first shifted inverse transformed coefficients having a bit depth less than the first direction inverse transformed coefficients;
• clipping the first shifted inverse transformed coefficients to the predetermined bit depth to generate second clipped coefficients;
• and
• one-dimension inverse transforming the second clipped coefficients in the second direction to determine the decoded residue.