Complexity Metrics for VVC Decoder Power Reduction in Green Metadata

This paper discusses the new complexity metrics for VVC decoder power reduction introduced in the 3 rd edition of the Green Metadata standard. The standard defines dedicated syntax elements that represent the expected software decoding complexity with a high accuracy. Using a simple complexity model, which can be trained for any VVC decoder software implementation, the receiver of the video can estimate the processing complexity to decode the subsequent video segment. Afterwards, it can adjust the clock frequency of the processor to keep the real-time playback constraint. By reducing the frequency of the processor, a significant amount of energy is saved. In this paper, we present the syntax elements, their meaning, and show that they can accurately estimate the processing complexity of various software decoder implementations with errors below 11%. Furthermore, we present a processor-frequency-control algorithm and apply it to a development board performing VVC video decoding. Measurements reveal that the complexity metric signaling can lead to up to 30% of energy savings.