earticle

영어

The growing demand for advanced mobile multimedia let the wireless mobile internet access be developed rapidly. The current mobile network is capable of providing flexible quality of service mechanisms including exact estimation of network bandwidth. In this paper, we propose a new GOP level rate control algorithm which can accurately estimate an initial QP according to the estimated network bandwidth. In H.264/AVC, the first frame of a GOP is encoded in intra mode which generates a large number of bits. The amount of bits for I-frame affects the qualities of the following frames of a GOP since they are encoded using the remaining bits of the bits allocated to the GOP. In addition, the first frame is used for the inter mode encoding of the following frames. Thus, the initial QP affects the following frames as well as the first frame. In the proposed algorithm, we observe the relation between the initial QP and the number of bits of I-frame in a GOP. Based on the observation, we propose a new method to estimate the optimal initial QP which maximizes the PSNR of a GOP. It is shown by experimental results that the proposed algorithm predicts the optimal initial QP accurately and thus achieves better PSNR performance than that of the existing algorithm.