A Unified 4/8/16/32-Point Integer IDCT Architecture for Multiple Video Coding Standards

4 or 8-point IDCT are widely used in traditional video coding standards. However larger size (16/32-point) IDCT has been proposed in the next generation video standard such as HEVC. To fulfill this requirement, this work proposes a fast computational algorithm of large size integer IDCT. A unified VLSI architecture for 4/8/16/32-point integer IDCT is also proposed accordingly. It can support the following video standards: MPEG-2/4, H.264, AVS, VC-1 and HEVC. Multiplier less MCM (Multiple Constant Multiplication) is used for 4/8-point IDCT. The regular multipliers and sharing technique are used for 16/32-point IDCT. The transpose memory uses SRAM instead of the traditional register array in order to further reduce the hardware overhead. It can support real-time decoding of 4K×2K (4096×2048) 30fps video sequence at 191MHz working frequency, with 93K gate count and 18944-bit SRAM. We suggest a normalized criterion called design efficiency to compare with previous works. It shows that this design is 31% more efficient than previous work.