After comparing 5,000 streaming clips from 500 titles using x264, x265, and libvpx codecs, Netflix found x265’s implementation of HEVC to be the most efficient while offering the highest quality. However, “whether that matters in light of compatibility and licensing issues isn’t so obvious,” notes Streaming Media. The study, which focused on VOD rather than live, compared codecs and not specifications (instead of comparing encoding specs, Netflix compared implementation of the specs). “Netflix’s tests clearly show that x265 is 20 percent more efficient than libvpx when encoding premium content using the most stringent settings, and measuring quality with VMAF.”