Search results

The purpose of this paper is to introduce an efficient rate control algorithm for the H.264/AVC video coding in wireless communication. The adaptive rate control algorithm can reduce rate fluctuation, effectively prevent the skipping frame, and be suitable to the characteristics of wireless channel. The experimental result indicates that this plan can guarantee the quality of service of video transmission.

A motion complexity measure is developed to enhance the existing mean of absolute difference (MAD)‐based algorithm and is applied to bit allocation for rate control. Time and space relativities in frames are also used in the proposed rate control algorithm for MAD prediction. A quantitative parameter (QP) control scheme is used to adjust the computed QP based on actual encoding results of previous coded macroblocks (MBs) in a frame.

The proposed rate control algorithm always outperforms JM 8.6. The adaptive MAD model can reduce the prediction error. Both the subjective and objective reconstructed video qualities are improved, and the luminance PSNR is increased by up to 0.53 dB (or an average of around 0.37 dB).

The adaptive rate control algorithm based on motion complexity and MAD prediction with space and time relativities will be suitable for wireless communication applications.

The first purpose of this paper is to propose a scalable video coding scheme providing flexibility in video transmission, especially under wireless environment. The second purpose is to analyze the problem of lengthening the key frame interval in distributed video coding (DVC), and propose an approach to improve the rate‐distortion (RD) performance of DVC for long group‐of‐frames (GOF) size.

In the proposed scheme, a base layer is first obtained from an H.264 coder. When a DVC coder is then used to code the enhancement layer, information in processing the base layer is extracted and analyzed to make multiple side‐information available and reduce error accumulation for DVC coding, thus further improving the performance of the DVC coder.

By dividing video into base and enhancement layers, the combined video coding architecture enables a flexible video transmission. In addition, several methods are used to improve the RD performance in DVC coding. Simulation shows that the proposed scheme outperforms non‐scalable DVC for long GOF size.

Prediction from the decoding loop in base layer encoder largely reduces enhancement layer spatial redundancy. Multiple side‐information provides better estimation for DVC reconstruction. Long prediction loop is more reliable because error accumulation is effectively compensated.