Previously, "[f]or patent reasons, Firefox [did] not directly support MP3; instead, platform-native libraries [were] used to support MP3."[0] Now it uses ffvpx,

Previously, "[f]or patent reasons, Firefox [did] not directly support MP3; instead, platform-native libraries [were] used to support MP3."[0] Now it uses ffvpx, which is their fork of ffmpeg. [1] [2] [0] https://developer.mozilla.org/en-US/docs/Web/Media/Formats/Audio_codecs https://developer.mozilla.org/en-US/docs/Web/Media/Formats/A... [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1582271 https://bugzilla.mozilla.org/show_bug.cgi?id=1582271 [2] https://github.com/mozilla/gecko-dev/blob/master/media/ffvpx/README_MOZILLA https://github.com/mozilla/gecko-dev/blob/master/media/ffvpx...