From d8fb15b3d9a345d0c936e036b47a7a0708ffbb74 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Sat, 30 Oct 2021 04:42:10 +0200
Subject: [PATCH] codec: audio type with 5 lossy music formats

Some readily available facts and opinions about the most popular audio
codecs AFAIK.
---
 codec-audio.inc.pl | 113 +++++++++++++++++++++++++++++++++++++++++++++
 codec.plp          |   4 +-
 2 files changed, 115 insertions(+), 2 deletions(-)
 create mode 100644 codec-audio.inc.pl

diff --git a/codec-audio.inc.pl b/codec-audio.inc.pl
new file mode 100644
index 0000000..5bd336d
--- /dev/null
+++ b/codec-audio.inc.pl
@@ -0,0 +1,113 @@
+use utf8;
++{
+codec => {
+	mp3 => {
+		name => '<abbr title="MPEG-1 Audio Layer III">MP3</abbr>',
+		available => 1991,
+	},
+	vorbis => {
+		name => 'Vorbis',
+		available => 2000,
+	},
+	opus => {
+		name => 'Opus',
+		available => 2012,
+	},
+	aac => {
+		name => '<abbr title="Advanced Audio Coding">AAC</abbr>',
+		available => 1997,
+	},
+	atrac => {
+		name => '<abbr title="Adaptive Transform Acoustic Coding">ATRAC</abbr>',
+		available => 1992,
+	},
+},
+feature => {
+	default => {
+		children => [qw( quality limits royalties support )],
+	},
+	quality => {
+		name => 'compression quality',
+		children => [qw( quality_music quality_speech quality_ll )],
+		score => {
+		},
+	},
+	quality_music => {
+		name => 'music',
+		score => {
+			mp3  => 3,
+			atrac => 2,
+			vorbis => 4,
+			aac  => 5,
+			opus => 5,
+		},
+	},
+	quality_speech => {
+		name => 'speech',
+		score => {
+			mp3  => 3,
+		},
+	},
+	quality_ll => {
+		name => 'lossless',
+		score => {
+			mp3  => 'n',
+			vorbis => 'n',
+			opus => 'n',
+			flac => 4,
+		},
+	},
+	limits => {
+		children => [qw( channels bitrate latency peeling )],
+		score => {
+		},
+	},
+	channels => {
+		score => {
+			mp3  => [3, 6, 'stereo, extended to upto 5.1'],
+			vorbis => [4, 255],
+			opus => [4, 255],
+		},
+	},
+	peeling => {
+		name => 'bitrate peeling',
+		score => {
+			vorbis => [3, undef, 'yes but "unusable" quality'],
+			mp3  => 'n',
+			opus => 'n',
+			aac  => 'n',
+		},
+	},
+	latency => {
+		name => 'frame size (ms)',
+		score => {
+			mp3 => [3, 26, 'typical version and layer has 1152 samples at 44kHz'],
+			opus => [5, 2.5],
+		},
+	},
+	bitrate => {
+		name => 'minimal bitrate',
+		score => {
+			mp3 => [4, 8],
+			opus => [4, 6],
+		},
+	},
+	royalties => {
+		score => {
+			mp3  => [5, undef, 'expired'],
+			vorbis => 5,
+			opus => [4, undef, 'open and free design'],
+			atrac => [2, undef, 'proprietary, but the original patents have expired'],
+		},
+	},
+	support => {
+		score => {
+			mp3  => 5,
+			vorbis => 4,
+			aac  => 4,
+			opus => 4,
+			atrac => 1,
+		},
+	},
+},
+}
diff --git a/codec.plp b/codec.plp
index 2349b1d..b2c3407 100644
--- a/codec.plp
+++ b/codec.plp
@@ -17,7 +17,7 @@ Html({
 	'],
 	stylesheet => [qw'light circus dark red'],
 	data => [qw'codec.inc.pl'],
-	raw => '<style>td,th {width:10%} tbody th {white-space:nowrap}</style>',
+	raw => '<style>td,th {width:8%} tbody th {white-space:nowrap}</style>',
 });
 
 my $info = do "codec-$page.inc.pl";
@@ -60,7 +60,7 @@ while (defined (my $feat = shift @feat)) {
 			}
 		}
 		printf '<td class="l%d"', $score;
-		printf ' title="%s"', $_ for $title // ();
+		printf ' title="%s"', EscapeHTML($_) for $title // ();
 		print '>', $data;
 	}
 	say '</td>';
-- 
2.30.0