Implementation of Different Architectures of 4x4 Integer DCT For H.264/AVC Encoder

Abstract—This paper presents an overview and different implementations of the 4x4 Integer Discrete Cosine Transform (DCT) used for the H.264 standard, also presenting the Utilization Report and the Maximum Operating Frequency for each implementation. The H.264 standard specifies the use of Integer DCT to decompose the results of inter prediction and intra prediction from spatial to Frequency Domain. We implemented the 2-D direct multiplication, the 1-D (butterfly) method and the 2-D multiplication with adders. All conditions being equal, the results show that, 2-D with adders and 1-D implementations outperform the Direct 2-D multiplication. However, the 2-D with adders uses less resources than the 1-D butterfly and still achieves a relatively high frequency.