Adaptive Accordion Transformation Based Video Compression Method on HEVC

Fast processing speed and high compression ratio are always expected for video coding. But generally it is hard to compromise between each other since high compression ratio usually requires high coding complexities. Ouni et al. proposed a novel method called accordion-based (ACC) coding in which multiple video frames are combined into an accordion-like representation for compression and it can achieve high compression ratio with low coding complexity. For low-motion videos at high bit-rates, its coding efficiency is close to H.264/AVC. However, it may no longer have benefit when applying the ACC to HEVC because HEVC has much better coding efficiency than H.264/AVC. Besides, it is not likely that all the frames in a video sequence are low-motion and thus suitable for ACC coding. To cope with these problems, in this paper we propose an adaptive method which dynamically switches between accordion-based coding and traditional HEVC coding according to the characteristics of video frames. The experiment result shows that the proposed method can achieve up to 11.5% of total bit-rate saving and 56.1% of encoding time saving, compared to traditional HEVC coding.