Low Delay Complexity Constrained Encoding

TL;DR: A technique to control complexity by deciding between 2Nx2N merge mode and full encoding, at different Coding Unit (CU) depths is proposed, demonstrating fast convergence to a given complexity threshold after a maximum of 10 frames, and a limited loss in rate-distortion performance.

Abstract: Complex software appliances typically consist of multiple software processes running concurrently to exploit the available computational resources in the hardware. However, the computational complexity of these software processes is often variable and the processes can interfere with each other. This can be an issue for real-time applications with a fixed deadline like low delay video encoding. In the context of High Efficiency Video Coding (HEVC), a limited number of publications have focused on controlling the complexity of an HEVC video encoder. In this paper, we propose a technique to control complexity by deciding between 2Nx2N merge mode and full encoding, at different Coding Unit (CU) depths. Our results demonstrate fast convergence to a given complexity threshold after a maximum of 10 frames, and a limited loss in rate-distortion performance (on average 2.84% Bjontegaard delta rate for 60% complexity reduction).