This paper introduces an adaptive GOP structure (AGS), which adaptively defines the GOP structure according to the time-varying temporal properties of video sequences, and thus improves the coding efficiency of the MPEG & ITU-T's Joint Scalable Video Coding (JSVC) scheme, the method proposed in this paper, which adaptively modifies the size of GOP based on the image characteristics of video sequence, improves the coding efficiency up to 0.77 dB compared to the JSVC JSVM (Joint Scalable Video Model).

Various scanning algorithms have been proposed to enhance the performance of intra prediction of H.264 codec. In this paper, an adaptive scanning scheme is proposed to achieve the entropy coding gain in intra coding, where scanning patterns are updated based on the probabilistic distribution of quantized coefficients of previous macroblocks so that the consecutive zeros are located at the rear part of the scanned data stream. Simulation results show that the average bit-rate reduction is about 2.15% in common test conditions.