MPEG-4 one-pass VBR rate control for digital storage

Abstract

One-pass, variable bitrate (VBR), rate control is ideally suited to the requirements of real-time video encoding for the purpose of digital storage. Previous MPEG 1-pass VBR rate control algorithms have been based on appropriate selection of quantization scale parameters for controlling the bitrate and quality of the output bitstream. The major disadvantage of relying solely on quantization scales, for rate-control, is the introduction of significant perceptual distortion when high quantization scales are used. In this paper we propose an MPEG-4, 1-pass, VBR rate-control scheme that relies on selective use of the MPEG-4 reduced resolution mode to supplement modulation of the quantization scale and provide an effective rate control strategy. Experimental results show that the proposed algorithm effectively can encode high-complexity, standard definition (720×480) video sequences at rates as low as 750 kbps without incurring significant perceptual artifacts.