An Area-Efficient Variable-Size Fixed-Point DCT Architecture for HEVC Encoding

This paper proposes an area-efficient fixed-point architecture for the computation of the discrete cosine transform (DCT) of multiple sizes in high efficiency video coding (HEVC). This result is obtained by comparing different DCT factorizations in order to find the most suitable one for implementation in the HEVC encoder. The recursive structure of fast algorithms, which decompose the N-point DCT by means of two N/2-point DCTs, is exploited to execute computations of small-size DCTs in parallel, thus maximizing the hardware reusability while maintaining a constant throughput. The simulation results prove that the proposed solution features reduced rate-distortion losses, with relevant complexity saving compared with the state-of-the-art implementations. Finally, the proposed architecture is exploited to design two families of architectures for the 2D-DCT, namely, folded and full-parallel.