http://wccftech.com/google-software-decoder-pixel-hdr/

Google introduced HDR playback in YouTube just a few days ago, but the feature wasn’t expected to be supported in its own flagship lineup. Popular Android devices like Samsung’s Galaxy S8 and LG’s G6 come with built-in support for HDR video. But, not the Google Pixel and Pixel XL. Apparently, Google couldn’t afford its customers missing up on the awesomeness that is HDR video and has brought in a software solution.

Folks over at Android Police first spotted Google Pixel and Pixel XL in the supported list of YouTube HDR playback. But, how is that support possible? In response to this curiosity, Google has said that its Pixels are doing YouTube HDR in software.