Scaled zero coefficient-aware IDCT algorithm for fast video decoding

Proposed is a scaled zero coefficient-aware fast inverse discrete cosine transform (IDCT) algorithm that substantially outperforms the existing fixed-point 8×8 IDCT standard. The concept of the fixed-point approximation with accurate dyadic terms is applied to the zero coefficient-aware IDCT algorithm, improving the computational complexity of the authors' previous work. The experimental results show that the running time of the proposed scaled zero coefficient-ware algorithm is faster than that of the fixed-point 8×8 IDCT standard by a speed-up factor of 2.0 times on average and up to 2.6 times for the HD sequences.