The decoder is modified by activating certain power-saving mechanisms on an increasing number of frames given a level from 0 to 12. Level 0 is the compliant HEVC decoder with no power savings. Levels 1 to 12 provide increasing amounts of power savings by applying the following mechanisms: turning off deblocking/SAO filters and using a low-complexity interpolation filter.
Tested on two platforms: ARM-based Exynos and Intel.
About 20% and 10% power savings were shown at Level 12 for the random-access and all-intra scenarios, respectively.
On both platforms, a linear trend was observed for PSNR-degradation vs. Power saving. Since power-saving is proportional to complexity reduction, this result suggests that a (psnr-degradation, complexity reduction) pair can be used as metadata.
Further study is encouraged to address the following:
Show linear relation between power saving and complexity reduction.
Explain the usage of the proposed metadata based on the #1.
Show power saving measured over the entire mobile device. The Monsoon power monitor (https://www.msoon.com/LabEquipment/PowerMonitor/) can be used for this purpose.
Provide video clips for subjective viewing.
Check that for the same power reduction, the metadata provides better subjective quality than would be obtained by just increasing the QP.
Check that, for the same bitrate, at Level 12, the metadata provides at least the same quality as AVC, but with more power-saving.