SIMD implementation of integer DCT and hadamard transforms in H.264/AVC encoder

This paper investigates Single Input Multiple Data (SIMD) implementations of the 4×4 integer Discrete Cosine Transforms (DCT) and 4×4 Hadamard transforms in H.264/AVC video encoders. Integer DCT transforms decomposes the video signal from the spatial or image domain to the frequency domain while the Hadarmad transforms decomposes the luminance and chrominance component of the same video signal. Results show that for the same Peak Signal to Noise Ratio (PSNR) and at quality factor of eight (8), integer DCT and Hadamard transforms have a computation time gain of 14000ms and 17000ms representing a speed up of 45% and 50% compared to the matrix multiplication method respectively. At these computation time gains our implementation is suited for use in real-time video broadcasting/internet applications and in low bandwidth environments.