Interactive partial video decoding for viewing resolution adaptation

High-definition (HD) and super-high-definition (SHD) videos become more and more popular for various video applications, including video capture and playback on portable devices. Because of the resolution mismatch between HD/SHD video and the low resolution screen of portable devices, the video is fully decoded and then sown-sampled for the display, which causes a waste of both computational power and memory bandwidth. In this paper, a user-defined region of interest (ROI) oriented partial decoding scheme for H.264/AVC is proposed to achieve low-power and good subjective visual quality of decoding/display for viewing resolution adaptation. The proposed partial decoding scheme works basing on the adaptive ROI tracking. The motion-vector (MV) adaptation is adopted for maintaining the visual quality in ROI. The simulation results show that, the displayed partial decoded sequence provides better subjective visual quality, more details, and very small PSNR drop in ROI compare to original one. And the partial decoder achieves about 48.34% decoding time reduction averagely, which means lower computational complexity and power consumption. The proposal is especially useful for displaying HD video on the portable devices in which the battery life is a crucial factor.