| | |
Summary: FRAME BIT ALLOCATION FOR H.264 USING CAUCHY-DISTRIBUTION BASED SOURCE
MODELLING
Nejat Kamaci and Yucel Altunbasak
Center for Signal and Image Processing
Georgia Institute of Technology
Atlanta, GA 30332
email:{kamaci,yucel}@ece.gatech.edu
ABSTRACT
Based on the observation that a Cauchy density is more accurate
in estimating the distribution of the AC coefficients than the tra-
ditional Laplacian density for H.264 video coders, a rate model
with improved accuracy is derived. Using the new rate model,
a frame bit-allocation algorithm for the rate control of an H.264
video coder is developed. Extensive analysis with carefully se-
lected anchor video sequences demonstrates a 0.43 dB average
PSNR improvement over the JM 8.4 rate control algorithm, and
a 0.27 dB average PSNR improvement over the TM5-based bit-
allocation algorithm that has recently been proposed for H.264 by
Ma et al. The analysis also demonstrates 20% and 60% reductions
in PSNR variation among the encoded pictures when compared to
|
