We propose an end-to-end approach to describe the energy usage of video delivery within a content delivery framework, and use this to investigate the energy usage behavior of two popular coding schemes, namely, H.264/AVC and H.265/HEVC. Our study based on the proposed model is backed up by measurements of encoding and decoding energy usage of a sample video and shows that, from an end-to-end perspective, taking into account all the elements of a content delivery network, neither of the coding formats is always dominant in terms of energy saving. We also find that the popularity of video content is a key parameter for predicting which encoding scheme saves most energy. In particular, we find that H.265 encoded content results in lower energy usage if the content is highly popular. On the other hand, for a content with predicted low popularity, more saving is achieved if H.264/AVC is used. This lead us to calculate a hybrid content delivery scheme, where the contents with low popularity are encoded and delivered in H.264/AVC format, whereas content of high popularity are encoded and delivered in the H.265/HEVC format. Also, our findings offer new insights into which elements of energy usage should be the focus of future research.
['Mohammadhassan Safavi', 'Saeed Bastani', 'Zhi Zhang', 'Martti Forsell', 'Olli Mämmelä', 'Björn Landfeldt']
A study on energy used to deliver H.264/AVC and H.265/HEVC video content