Apple's HomePod, Files in iOS, and QuickTime Player in macOS all support FLAC playback, but Apple's media management tool iTunes still does not making it more difficult for Apple users to use the high-quality file format than it could be.
The support for FLAC files in the HomePod was tucked away in the tail-end of the supported audio formats technical data. It is unclear why the format is supported by Apple, as it has continued to not support the format in iTunes since the format gained wide acceptance after the 1.3 version of the format in 2013.
FLAC files can now be played back in QuickTime Player in macOS. However, other players like VLC handle the files better, with playlist and other niceties that aren't in QuickTime Player.
Audio sources encoded to FLAC are typically reduced to 50 percent of their original size on a CD, depending on the characteristics of the track and some encoding settings. Apple's lossless ALAC format is similar in audio quality, but not as widely supported by third parties as FLAC is — but is obviously fully supported in iTunes.
Apple's first moves to support FLAC were in iOS 11. Early beta versions added the ability to play back single tracks encoded in FLAC format in the Files app, using the standard media player.
8 Comments
FLAC and ALAC are just lossless compression envelopes for the same PCM data inside. The music is identical between the two. FLAC was invented as an open sourced way to handle PCM data since formats like WAV and ALAC weren't open source and free from potential legal entanglements. Since then, ALAC is open sourced now too but the audiophile community largely endorsed FLAC but music sites like HDTracks.com allow you to purchase either FLAC or ALAC music.
Eyebrows were raised when High Sierra and iOS 11 knew what a FLAC file was and could even play them! But iTunes hasn't been changed to deal with FLAC but considering the upcoming HomePod FLAC compatibility, it's only a matter of time. After all, how else is a FLAC file supposed to get to the HomePod? And iTunes already supports WAV and AIFF files for lossless audio (Apple invented PCM audio files with the Apple Interchange File Format "AIFF" back in the late 1980s) and MP3 and AAC in the lossy audio realm.
It was my understanding that Apple’s creation of ALAC was that the decompression algorithm for FLAC could not be optimised to run on the low powered processors inside of early iPods. ALAC had inferior compression but could be decoded using integer math and so done in real time.
As noted on the FLAC homepage, it requires only integer hardware to decode. I expect ALAC had more to do with keeping the "m4a" packaging format for consistency with AAC encoded files. Or just plain old 'not invented here'
Leaving iTunes out of format updates coming to other devices signals to me that a significant change in coming to the various services iTunes currently provides. Apple seems reluctant to sink much effort into maintaining the desktop app probably because there's a major change coming.