A Flexible Heterogeneous Hardware/Software Solution for Real-Time HD H.264 Motion Estimation

Quarter-pixel accuracy and variable block-size significantly enhance compression performances of the MPEG-4 AVC/H.264 video compression standard over its predecessors, but also significantly increase computation requirements. Firstly, a digital signal processor (DSP)-based solution that achieves real-time integer motion estimation is proposed. Fractional-pixel refinement is too computationally intensive to be efficiently processed on a software-based processor. To address this restriction, a flexible and low complexity VLSI subpixel refinement coprocessor is designed. Thanks to an improved datapath, a high throughput is achieved with low logic resources. Finally, an heterogeneous (DSP-field-programmable gate array) solution to handle real-time motion estimation with variable block-size and fractional-pixel accuracy for high-definition video is studied. This solution, combining programmability and efficiency, achieves motion estimation of 720 p sequences at up to 60 fps.