Apple’s HomePod Will Support Lossless FLAC Audio Playback
Apple's HomePod, Files in iOS, and QuickTime Player in macOS will all support FLAC audio playback.
FLAC
iOS 11 to Support FLAC Playback for iPhone X, iPhone 8, and iPhone 8 Plus
Free Lossless Audio Codec (FLAC) brings the full quality of the original recording via lossless compression of digital audio at the expense of storage and bandwidth.