X-Git-Url: http://git.shiar.net/sheet.git/blobdiff_plain/4ca5c383de798f0aa6b1b5e149c620a77b753400..c106d1bc4d686595384f6b3d4cc2a28cbed70d1f:/codec.inc.pl

diff --git a/codec.inc.pl b/codec.inc.pl
index c70fc38..f4d90e3 100644
--- a/codec.inc.pl
+++ b/codec.inc.pl
@@ -36,7 +36,7 @@ codec => {
 },
 feature => {
 	default => {
-		children => [qw( quality_photo quality_art speed limits features royalties )],
+		children => [qw( quality_photo quality_art speed limits features royalties overhead support )],
 	},
 	quality_photo => {
 		name => 'compression (photo)',
@@ -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',
@@ -428,15 +428,43 @@ 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 => [],
 	},
+	support => {
+		score => {
+			jpeg => 5,
+			gif  => 5,
+			png  => 5,
+			jp2k => [2, undef, 'Apple only'],
+			webp => [4, undef, 'modern browsers'],
+			heic => [1, undef, 'stored by latest cameras, no browser support'],
+			avif => [3, undef, 'all modern browsers except Safari and Edge'],
+			jxl  => [2, undef, 'upcoming in most browsers'],
+		},
+	},
+	overhead => {
+		name => 'container overhead (file size)',
+		score => {
+			png  => [3,  67, 'upto 70 bytes for specific RGBA'],
+			jpeg => [2, 160, '159 bytes minimum for gray, 288 for specific colours'],
+			gif  => [4,  35, '43 bytes for transparent'],
+			webp => [4,  34, 'black or transparent lossless; 44-92 bytes lossy'],
+			bpg  => [4,  31, 'lossy 29-62 bytes, lossless 37-160'],
+			flif => [5,  14, 'black or transparent; 20 bytes for specific RGBA'],
+			pnm  => [5,   8, 'monochrome text PBM; 12 bytes PPM; 69 bytes PAM'],
+			jxl  => [5,  12, '512×256 black pixels'],
+			avif => [1, 282, 'container overhead; 457 bytes with alpha'],
+			jp2k => [2, 123, 'experimental results, likely not optimal'],
+			heic => [1, 386],
+		},
+	},
 },
 }