Support aac & mpeg-2 (#266)

core.d.ts

@@ -120,7 +120,9 @@ declare namespace core {
 		| 'spx'
 		| 'ogx'
 		| 'arrow'
-		| 'shp';
+		| 'shp'
+		| 'aac'
+		| 'mp1';
 
 	type MimeType =
 		| 'image/jpeg'
@@ -233,7 +235,8 @@ declare namespace core {
 		| 'image/x-fujifilm-raf'
 		| 'video/x-m4v'
 		| 'video/3gpp2'
-		| 'application/x-esri-shape';
+		| 'application/x-esri-shape'
+		| 'audio/aac'
 
 	interface FileTypeResult {
 		/**

core.js

@@ -985,35 +985,6 @@ async function fromTokenizer(tokenizer) {
 		};
 	}
 
-	// Check for MPEG header
-	if (
-		check([0x49, 0x44, 0x33]) || // ID3 header
-		check([0xFF, 0xE2], {mask: [0xFF, 0xE6]}) // MPEG 1 or 2 Layer 3 header
-	) {
-		return {
-			ext: 'mp3',
-			mime: 'audio/mpeg'
-		};
-	}
-
-	if (
-		check([0xFF, 0xE4], {mask: [0xFF, 0xE6]}) // MPEG 1 or 2 Layer 2 header
-	) {
-		return {
-			ext: 'mp2',
-			mime: 'audio/mpeg'
-		};
-	}
-
-	if (
-		check([0xFF, 0xF8], {mask: [0xFF, 0xFC]}) // MPEG 2 layer 0 using ADTS
-	) {
-		return {
-			ext: 'mp2',
-			mime: 'audio/mpeg'
-		};
-	}
-
 	if (check([0x00, 0x00, 0x00, 0x0C, 0x6A, 0x50, 0x20, 0x20, 0x0D, 0x0A, 0x87, 0x0A])) {
 		// JPEG-2000 family
 
@@ -1045,15 +1016,6 @@ async function fromTokenizer(tokenizer) {
 		}
 	}
 
-	if (
-		check([0xFF, 0xF0], {mask: [0xFF, 0xFC]}) // MPEG 4 layer 0 using ADTS
-	) {
-		return {
-			ext: 'mp4',
-			mime: 'audio/mpeg'
-		};
-	}
-
 	// -- Unsafe signatures --
 
 	if (
@@ -1193,40 +1155,48 @@ async function fromTokenizer(tokenizer) {
 
 	// Check for MPEG header at different starting offsets
 	for (let start = 0; start < 2 && start < (buffer.length - 16); start++) {
-		if (
-			check([0xFF, 0xE2], {offset: start, mask: [0xFF, 0xE6]}) // MPEG 1 or 2 Layer 3 header
-		) {
-			return {
-				ext: 'mp3',
-				mime: 'audio/mpeg'
-			};
-		}
+		// Check MPEG 1 or 2 Layer 3 header, or 'layer 0' for ADTS (MPEG sync-word 0xFFE)
+		if (buffer.length >= start + 2 && check([0xFF, 0xE0], {offset: start, mask: [0xFF, 0xE0]})) {
+			if (check([0x10], {offset: start + 1, mask: [0x16]})) {
+				// Check for (ADTS) MPEG-2
+				if (check([0x08], {offset: start + 1, mask: [0x08]})) {
+					return {
+						ext: 'aac',
+						mime: 'audio/aac'
+					};
+				}
 
-		if (
-			check([0xFF, 0xE4], {offset: start, mask: [0xFF, 0xE6]}) // MPEG 1 or 2 Layer 2 header
-		) {
-			return {
-				ext: 'mp2',
-				mime: 'audio/mpeg'
-			};
-		}
+				// Must be (ADTS) MPEG-4
+				return {
+					ext: 'aac',
+					mime: 'audio/aac'
+				};
+			}
 
-		if (
-			check([0xFF, 0xF8], {offset: start, mask: [0xFF, 0xFC]}) // MPEG 2 layer 0 using ADTS
-		) {
-			return {
-				ext: 'mp2',
-				mime: 'audio/mpeg'
-			};
-		}
+			// MPEG 1 or 2 Layer 3 header
+			// Check for MPEG layer 3
+			if (check([0x02], {offset: start + 1, mask: [0x06]})) {
+				return {
+					ext: 'mp3',
+					mime: 'audio/mpeg'
+				};
+			}
 
-		if (
-			check([0xFF, 0xF0], {offset: start, mask: [0xFF, 0xFC]}) // MPEG 4 layer 0 using ADTS
-		) {
-			return {
-				ext: 'mp4',
-				mime: 'audio/mpeg'
-			};
+			// Check for MPEG layer 2
+			if (check([0x04], {offset: start + 1, mask: [0x06]})) {
+				return {
+					ext: 'mp2',
+					mime: 'audio/mpeg'
+				};
+			}
+
+			// Check for MPEG layer 1
+			if (check([0x06], {offset: start + 1, mask: [0x06]})) {
+				return {
+					ext: 'mp1',
+					mime: 'audio/mpeg'
+				};
+			}
 		}
 	}
 }

package.json

@@ -161,7 +161,9 @@
 		"dcm",
 		"mpc",
 		"arrow",
-		"shp"
+		"shp",
+		"aac",
+		"mp1"
 	],
 	"devDependencies": {
 		"@types/node": "^12.7.2",

readme.md

@@ -184,6 +184,7 @@ Returns a set of supported MIME types.
 - [`mov`](https://en.wikipedia.org/wiki/QuickTime_File_Format)
 - [`avi`](https://en.wikipedia.org/wiki/Audio_Video_Interleave)
 - [`mpg`](https://en.wikipedia.org/wiki/MPEG-1)
+- [`mp1`](https://en.wikipedia.org/wiki/MPEG-1_Audio_Layer_I) - MPEG-1 Audio Layer I
 - [`mp2`](https://en.wikipedia.org/wiki/MPEG-1_Audio_Layer_II)
 - [`mp3`](https://en.wikipedia.org/wiki/MP3)
 - [`ogg`](https://en.wikipedia.org/wiki/Ogg)
@@ -271,6 +272,7 @@ Returns a set of supported MIME types.
 - [`mie`](https://en.wikipedia.org/wiki/Sidecar_file) - Dedicated meta information format which supports storage of binary as well as textual meta information
 - [`shp`](https://en.wikipedia.org/wiki/Shapefile) - Geospatial vector data format
 - [`arrow`](https://arrow.apache.org) - Columnar format for tables of data
+- [`aac`](https://en.wikipedia.org/wiki/Advanced_Audio_Coding) - Advanced Audio Coding
 
 *SVG isn't included as it requires the whole file to be read, but you can get it [here](https://github.com/sindresorhus/is-svg).*
 

supported.js

@@ -119,7 +119,9 @@ module.exports = {
 		'ogx',
 		'mpc',
 		'arrow',
-		'shp'
+		'shp',
+		'aac',
+		'mp1'
 	],
 	mimeTypes: [
 		'image/jpeg',
@@ -232,6 +234,7 @@ module.exports = {
 		'image/x-fujifilm-raf',
 		'video/x-m4v',
 		'video/3gpp2',
-		'application/x-esri-shape'
+		'application/x-esri-shape',
+		'audio/aac'
 	]
 };

test.js

@@ -21,6 +21,11 @@ const types = supported.extensions.filter(ext => !missingTests.includes(ext));
 // Define an entry here only if the fixture has a different
 // name than `fixture` or if you want multiple fixtures
 const names = {
+	aac: [
+		'fixture-adts-mpeg2',
+		'fixture-adts-mpeg4',
+		'fixture-adts-mpeg4-2'
+	],
 	arw: [
 		'fixture',
 		'fixture2',
@@ -59,12 +64,10 @@ const names = {
 	],
 	mp2: [
 		'fixture',
-		'fixture-mpa',
-		'fixture-faac-adts'
+		'fixture-mpa'
 	],
 	mp3: [
 		'fixture',
-		'fixture-offset1',
 		'fixture-mp2l3',
 		'fixture-ffe3'
 	],
@@ -73,8 +76,7 @@ const names = {
 		'fixture-isom',
 		'fixture-isomv2',
 		'fixture-mp4v2',
-		'fixture-dash',
-		'fixture-aac-adts'
+		'fixture-dash'
 	],
 	tif: [
 		'fixture-big-endian',