Rate control using enhanced frame complexity measure for H.264 video

Xiaoquan Yi, Nam Ling
IEEE Workshop onSignal Processing Systems, 2004. SIPS 2004.  
Bit rate control is an important issue for wireless and Internet video streaming. This paper presents a revised rate control scheme based on an improved frame complexity measure. Rate control adopted by both MPEG-4 VM18 and H.264/AVC uses a quadratic rate-distortion (R-D) model that determines quantization parameters (QPs). Classical quadratic R-D model is suitable for MPEG-4 but it performs poorly for H.264/AVC because one of the important parameters, mean absolute difference (MAD), is
more » ... e (MAD), is predicted through a linear model, whereas the MAD used in MPEG-4 VM18 is the actual MAD. Inaccurately predicted MAD results in wrong QP and consequently degrades rate distortion optimization (RDO) performance in H.264/AVC. To overcome the limitation of the existing rate control schemes, we introduce an enhanced linear model for predicting MAD, utilizing some knowledge of current frame complexity. Moreover, we propose a more accurate frame complexity measure, namely, normalized MAD, to replace the current use of MAD parameter. Normalized MAD has a stronger correlation with optimally allocated bits than that of the predicted MAD. Finally, a dynamic bit allocation scheme among basic units is implemented. Extensive simulation results show that our method, with inexpensive computational complexity added, improves the average peak signal-to-noise ratio (PSNR) considerably by up to 1.2 dB and reduces PSNR variances significantly by up to 63%.
doi:10.1109/sips.2004.1363060 fatcat:ln5p6hl42za6de2uscvck2y6ma