Dynamic core allocation for energy efficient video decoding in homogeneous and heterogeneous multicore architectures

• Present dynamic core allocation for video decoding on homogeneous multicores.
• Present an energy-efficient video decoding method for heterogeneous multicores.
• Show energy savings with dynamic core allocation.
• Analyze factors influencing frame decoding time.

This paper describes two dynamic core allocation techniques for video decoding on homogeneous and heterogeneous embedded multicore platforms with the objective of reducing energy consumption while guaranteeing performance. While decoding a frame, the scheme measures “slack” and “overshoot” over the budgeted decode time and amortizes across the neighboring frames to achieve overall performance, compensating for the overshoot with the slack time. It allocates, on a per-frame basis, an appropriate number and types of cores for decoding to guarantee performance, while saving energy by using clock gating to switch off unused cores. Using the Sniper simulator to evaluate the implementation of the scheme on a modern embedded processor, we get an energy saving of 6%–61% while strictly adhering to the required performance of 75 fps on homogeneous multicore architectures. We receive an energy saving of 2%–46% while meeting the performance of 25 fps on heterogeneous multicore architectures. Thus, we show that substantial energy savings can be achieved in video decoding by employing dynamic core allocation, compared with the default strategy of allocating as many cores as available.