From: Mischa POSLAWSKY <perl@shiar.org>
Date: Fri, 29 Oct 2021 16:29:00 +0000 (+0200)
Subject: codec: technical values or details om hover
X-Git-Tag: v1.13~113
X-Git-Url: http://git.shiar.net/sheet.git/commitdiff_plain/a142c8ca12f907b4775231207eeb5819ae76f30a

codec: technical values or details om hover

Explain disputable ratings like royalties, and other optional annotations
to clarify included source values and maybe prevent complaints.
---

diff --git a/codec.inc.pl b/codec.inc.pl
index c70fc38..2b1f590 100644
--- a/codec.inc.pl
+++ b/codec.inc.pl
@@ -238,8 +238,8 @@ feature => {
 			png  => [4,  '2G²'],   # 2**31
 			jp2k => [5,  '4G²'],   # 2**32
 			webp => [1, '16k²'],   # 2**14
-			heic => [2, '8k×4k+'], # 8193x4320
-			avif => [3, '65k²+'],  # 2**16, 8193x4320 with profile
+			heic => [2,'8k×4k+', 'tilable, only 512×512 on Apple'], # 8193x4320
+			avif => [3, '65k²+', 'tilable, 7680×4320 with Advanced profile'], # 2**16
 			jxl  => [4,  '1G²'],   # 2**30
 		},
 	},
@@ -248,27 +248,27 @@ feature => {
 		name => 'precision (max. bit depth)',
 		score => {
 			jpeg => [2,  8],
-			gif  => [2,  8],
+			gif  => [1,  8, '256 colour palette per frame'],
 			png  => [4, 16],
 			jp2k => [5, 38],
 			webp => [2,  8],
-			heic => [3, 10],
-			avif => [3, 10],
-			jxl  => [5, 32],
+			heic => [3, 10], #TODO 16?
+			avif => [3, 12, '8, 10, 12 bit'],
+			jxl  => [5, 32, '24-bit integer or 32-bit float'],
 		},
 	},
 	color_444 => {
 		parent => 'limits',
-		name => 'can do (lossy) 4:4:4',
+		name => 'chroma subsampling',
 		score => {
-			jpeg => 'y',
-			gif  => 'y',
-			png  => 'y',
+			jpeg => ['y', undef, '4:2:0, 4:2:2, 4:4:4'],
+			gif  => [4, '✘'],
+			png  => [4, '✘'],
 			jp2k => 'y',
-			webp => 'n',
-			heic => 'n',
-			avif => 'y',
-			jxl  => 'y',
+			webp => [1, '4:2:0'],
+			heic => [1, '4:2:0'],
+			avif => ['y', undef, '4:2:0, 4:2:2, 4:4:4'],
+			jxl  => ['y', undef, 'for JPEG compatibility'],
 		},
 	},
 	hdr => {
@@ -289,14 +289,14 @@ feature => {
 		parent => 'limits',
 		name => 'maximum number of channels',
 		score => {
-			jpeg => [2, 4], # cmyk
-			gif  => [1, 3],
-			png  => [2, 4], # cmyk
+			jpeg => [3, 4, 'RGB or CMYK'],
+			gif  => [3, 3, 'RGB palette'],
+			png  => [3, 4, 'RGBA'],
 			jp2k => [5, 2**15],
-			webp => [2, 4],
-			heic => [3, 5],
-			avif => [3, 5],
-			jxl  => [4, 4099],
+			webp => [3, 4, 'RGBA'],
+			heic => [3, 3, 'RGB, separate alpha and depth'],
+			avif => [3, 3, 'RGB, separate alpha and depth'],
+			jxl  => [4, 4099, 'native XYB'],
 		},
 	},
 	features => {
@@ -318,7 +318,7 @@ feature => {
 		score => {
 			jpeg => [2, 'MJPEG'],
 			gif  => 'y',
-			png  => [4, 'APNG'],
+			png  => [4, 'APNG', 'later backwards-compatible extension'],
 			jp2k => [2, 'MJP2'],
 			webp => 'y',
 			heic => 'y',
@@ -428,13 +428,13 @@ feature => {
 		name => 'royalty-free',
 		score => {
 			jpeg => 5,
-			gif  => 5, # patents expired
+			gif  => [5, undef, 'patented before 2003'],
 			png  => 5,
-			jp2k => 3, # specs not freely available
-			webp => 4, # submarine risk
-			heic => 'n', # patents enforced
-			avif => 4,
-			jxl  => 4,
+			jp2k => [3, undef, 'ISO specification not freely available'],
+			webp => [4, undef, 'free format, low remaining risk of patent trolls'],
+			heic => ['n', undef, 'heavily patented'],
+			avif => [4, undef, 'free format, risk of patent trolls'],
+			jxl  => [4, undef, 'free format, risk of patent trolls'],
 		},
 		children => [],
 	},
diff --git a/codec.plp b/codec.plp
index 1ae734a..2e50794 100644
--- a/codec.plp
+++ b/codec.plp
@@ -41,7 +41,7 @@ while (defined (my $feat = shift @feat)) {
 	print '<tbody>' if $featinfo->{children};
 	printf '<tr><th>%s', $featinfo->{name} // $feat;
 	for (@codecs) {
-		my ($score, $data) = map { ref ? @$_ : $_ } $featinfo->{score}->{$_};
+		my ($score, $data, $title) = map { ref ? @$_ : $_ } $featinfo->{score}->{$_};
 		if (not defined $data) {
 			if (my $override = $BOOLSCORE{$score}) {
 				($score, $data) = @{$override};
@@ -50,7 +50,9 @@ while (defined (my $feat = shift @feat)) {
 				$data = '•' x ($score - 1);
 			}
 		}
-		printf '<td class="l%d">%s', $score, $data;
+		printf '<td class="l%d"', $score;
+		printf ' title="%s"', $_ for $title // ();
+		print '>', $data;
 	}
 	say '</td>';
 }