Fast Prediction Mode Decision in HEVC Using a Pseudo Rate-Distortion Based on Separated Encoding Structure

Abstract

A novel fast algorithm is suggested for a coding unit (CU) mode decision using pseudo rate‐distortion based on a separated encoding structure in High Efficiency Video Coding (HEVC). A conventional HEVC encoder requires a large computational time for a CU mode prediction because prediction and transformation procedures are applied to obtain a rate‐distortion cost. Hence, for the practical application of HEVC encoding, it is necessary to significantly reduce the computational time of CU mode prediction. As described in this paper, under the proposed separated encoder structure, it is possible to decide the CU prediction mode without a full processing of the prediction and transformation to obtain a rate‐distortion cost based on a suitable condition. Furthermore, to construct a suitable condition to improve the encoding speed, we employ a pseudo rate‐distortion estimation based on a Hadamard transformation and a simple quantization. The experimental results show that the proposed method achieves a 38.68% reduction in the total encoding time with a similar coding performance to that of the HEVC reference model.

Motion-Vector Refinement for Video Error Concealment Using Downhill Simplex Approach

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“…jI n ðMV xinit þ dx; MV yinit þ dyÞ À I out j; (2) where MV xinit , MV yinit , and I out denote the initial motion vector in the x and y directions, and pixels outside of the block boundary, respectively. In addition, I in (MV xinit , + dx, MV yinit + dy) indicates pixels inside the block generated using the estimated motion vector, and B denotes a set containing all pixels along the block boundary.…”

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“…Recently various advanced broadcasting technologies have been investigated and developed [1][2][3][4]. In the terrestrial broadcasting system, the transmission standards supporting 4K ultra-high definition (UHD) broadcasting service have been investigated and developed [5,6].…”