Novel rate control scheme for intra frame video coding with exponential rate–distortion model on H.264/AVC

Rate control regulates the output bit rate of a video encoder in order to obtain optimum visual quality within the available network bandwidth and to maintain buffer fullness within a specified tolerance range. Due to the benefits of intra-only encoding, such as less computational cost and less latency, it has been more and more widely used. In this paper, we propose an accurate intra-only rate control scheme for H.264/AVC, which includes a novel complexity measurement and a new rate–distortion (R–D) model. We also propose a linear rate–complexity model which takes the intercept into consideration to reduce the estimation error. The proposed R–D model is integrated by the linear rate–complexity model and an exponential rate–quantization model. Based on theoretical analysis and experimental validation, the proposed scheme has high bits prediction precision, and it can also accurately handle buffer fullness. Compared with JVT-W042, our algorithm achieves higher average PSNR and improves the coding quality up to 0.35 dB.

► A rate control scheme for H.264/AVC intra frame encoding is proposed.
► A new R–D model is integrated by a linear R–C model and an exponential R–Q model.
► Geometry gradient is adopted to measure the content complexity of intra-frames.
► Comparison and analysis between the real and predicted content complexity are given.