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

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. With these implementations, 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 fewer resources than the 1-D butterfly and still achieves a relatively high frequency.