A joint multi rate optimization framework for video adaptation in H.264/AVC

摘要

Due to the explosive growth in ubiquitous multimedia access, one needs to adapt the considerable number of pre-encoded video content to a wide variety of user constraints such as different resolution, bitrate, frame rate, processing power and platform. Current adaptation frameworks do not take the encoder into account. In other words the encoder optimizes its outcome for the base layer only, regardless of the remaining adaptation layers and the resulted distortion once the adaptation is applied. In this paper, a joint multi rate optimization algorithm has been proposed for H.264/AVC that generates an encoded bitstream that will have the minimum distortion across all the layers combined, hence providing an improved experience for a larger number of users. The proposed scheme, that only supports bitrate adaption, is independent of the adaptation algorithm and is applicable to most existing adaptation frameworks. Simulation results indicate that the proposed scheme improves the video quality by up to 0.8 dB. The quality improvement of the adapted content is more significant in lower bitrates where even small improvements are visually noticeable due to the inherent low quality in these bitrates.