I’ve noticed that when I play FLAC content through Plex/Web it transcodes it into MP3, presumably since that is the best supported format for browsers. Of course, I’m not sure what bitrate it is transcoded to, but I’d prefer if it just played the FLAC in the browser.
I was wondering if the team had considered integrating a JavaScript FLAC decoder for the Plex/Web client. You can find one here and there may be more.
This may be not be ideal for all browsers, but I’m playing this on the Plex Server itself, so decoding should be less work than transcoding, even when done in the browser. I imagine not everyone would want to play FLAC in their browser, so it could be toggled with a setting under Web > Player > Audio & Subtitles.