Rate control for H.264/AVC video coding and transmission over burst-error wireless channel

With the recent advancements in digital video technology, wireless video communication has become an important component in multimedia applications. Demand for the tetherless mobility of wireless communication is ever-increasing, and new applications are constantly being introduced. However, wireless channels typically are very noisy and have severe time-varying fading. In addition, most wireless systems are also subject to severe limitations in bandwidth and transmitted signal power, as well as stringent low delay requirements for conversational communication. In order to comply with these constraints, it is necessary to implement rate control at the video encoder in wireless video transmission applications.; In this dissertation we develop a novel rate control scheme for H.264 video coding and transmission over wireless channels, operating within a series of different constraints representative of a practical wireless system. Generally, a rate control algorithm includes three steps: target bit rate allocation, a rate quantization model, and parameter updates. In our research, we take into account the end-to-end delay, buffer delay, channel state, and codec constraints, and translate these constraints into the rate constraint, finally deducing the target bit rate. In order to predict the channel state, we employ a 15-state Markov model to simulate the process of fading and burst errors on the channel. For the rate quantization model, we incorporate the linear rate model, which uses a linear relationship between the bit rate and the percentage of zeros into the proposed rate control system, and we then use the statistical Laplacian distribution to simulate the DCT coefficients to find the corresponding quantization parameter (QP). All model parameters are updated after encoding each frame.; In order to evaluate the performance of the proposed rate control system, we have performed a series of simulations to compare the proposed rate control algorithm and the H.264 recommended algorithm. The experiment's results demonstrate the effectiveness of the proposed algorithm.