A Low Complexity MPEG Video Decoder with Arbitrary Downscaling Capability

This paper presents some new techniques to implement arbitrary downscaling in decoding MPEG video with very low complexity. The DCT block recomposition method, which was used in resizing static image, is introduced to downscale video in frequency domain with arbitrary factors. New motion compensation based on the block group motion evaluation is proposed to correspond to the downscaled IDCT. Block groups of regular motion and irregular motion are handled respectively to balance the computation cost and picture quality. Analysis indicates the great complexity reduction and experiments show the decoder performance on the MPEG-4 video sequence. These techniques will be beneficial to the video applications on the mobile devices and many other low end embedded systems