First release

node_modules/mux.js/test/utils/id3-generator.js

@@ -0,0 +1,74 @@
+/**
+ * Helper functions for creating ID3 metadata.
+ */
+
+'use strict';
+
+var stringToInts, stringToCString, id3Tag, id3Frame;
+
+stringToInts = function(string) {
+  var result = [], i;
+  for (i = 0; i < string.length; i++) {
+    result[i] = string.charCodeAt(i);
+  }
+  return result;
+};
+
+stringToCString = function(string) {
+  return stringToInts(string).concat([0x00]);
+};
+
+id3Tag = function() {
+  var
+    frames = Array.prototype.concat.apply([], Array.prototype.slice.call(arguments)),
+    result = stringToInts('ID3').concat([
+      0x03, 0x00,            // version 3.0 of ID3v2 (aka ID3v.2.3.0)
+      0x40,                  // flags. include an extended header
+      0x00, 0x00, 0x00, 0x00, // size. set later
+
+      // extended header
+      0x00, 0x00, 0x00, 0x06, // extended header size. no CRC
+      0x00, 0x00,             // extended flags
+      0x00, 0x00, 0x00, 0x02  // size of padding
+    ], frames),
+    size;
+
+  // size is stored as a sequence of four 7-bit integers with the
+  // high bit of each byte set to zero
+  size = result.length - 10;
+
+  result[6] = (size >>> 21) & 0x7f;
+  result[7] = (size >>> 14) & 0x7f;
+  result[8] = (size >>> 7) & 0x7f;
+  result[9] = size & 0x7f;
+
+  return result;
+};
+
+id3Frame = function(type) {
+  var result = stringToInts(type).concat([
+    0x00, 0x00, 0x00, 0x00, // size
+    0xe0, 0x00 // flags. tag/file alter preservation, read-only
+  ]),
+      size = result.length - 10;
+
+  // append the fields of the ID3 frame
+  result = result.concat.apply(result, Array.prototype.slice.call(arguments, 1));
+
+  // set the size
+  size = result.length - 10;
+
+  result[4] = (size >>> 21) & 0x7f;
+  result[5] = (size >>> 14) & 0x7f;
+  result[6] = (size >>> 7) & 0x7f;
+  result[7] = size & 0x7f;
+
+  return result;
+};
+
+module.exports = {
+  stringToInts: stringToInts,
+  stringToCString: stringToCString,
+  id3Tag: id3Tag,
+  id3Frame: id3Frame
+};