3 intro => 'Comparison of audio compression formats.',
6 name => '<abbr title="MPEG-1 Audio Layer III">MP3</abbr>',
21 name => '<abbr title="Advanced Audio Coding">AAC</abbr>',
26 name => '<abbr title="Adaptive Transform Acoustic Coding">ATRAC</abbr>',
33 children => [qw( quality limits royalties support )],
36 name => 'compression quality',
37 children => [qw( quality_music quality_speech quality_ll )],
67 children => [qw( channels bitrate latency peeling )],
73 mp3 => [3, 6, 'stereo, extended to upto 5.1'],
79 name => 'bitrate peeling',
81 vorbis => [3, undef, 'yes but "unusable" quality'],
88 name => 'frame size (ms)',
90 mp3 => [3, 26, 'typical version and layer has 1152 samples at 44kHz'],
95 name => 'minimal bitrate',
103 mp3 => [5, undef, 'expired'],
105 opus => [4, undef, 'open and free design'],
106 atrac => [2, undef, 'proprietary, but the original patents have expired'],