First release

node_modules/@videojs/vhs-utils/cjs/riff-helpers.js

@@ -0,0 +1,84 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.findFourCC = void 0;
+
+var _byteHelpers = require("./byte-helpers.js");
+
+var CONSTANTS = {
+  LIST: (0, _byteHelpers.toUint8)([0x4c, 0x49, 0x53, 0x54]),
+  RIFF: (0, _byteHelpers.toUint8)([0x52, 0x49, 0x46, 0x46]),
+  WAVE: (0, _byteHelpers.toUint8)([0x57, 0x41, 0x56, 0x45])
+};
+
+var normalizePath = function normalizePath(path) {
+  if (typeof path === 'string') {
+    return (0, _byteHelpers.stringToBytes)(path);
+  }
+
+  if (typeof path === 'number') {
+    return path;
+  }
+
+  return path;
+};
+
+var normalizePaths = function normalizePaths(paths) {
+  if (!Array.isArray(paths)) {
+    return [normalizePath(paths)];
+  }
+
+  return paths.map(function (p) {
+    return normalizePath(p);
+  });
+};
+
+var findFourCC = function findFourCC(bytes, paths) {
+  paths = normalizePaths(paths);
+  bytes = (0, _byteHelpers.toUint8)(bytes);
+  var results = [];
+
+  if (!paths.length) {
+    // short-circuit the search for empty paths
+    return results;
+  }
+
+  var i = 0;
+
+  while (i < bytes.length) {
+    var type = bytes.subarray(i, i + 4);
+    var size = (bytes[i + 7] << 24 | bytes[i + 6] << 16 | bytes[i + 5] << 8 | bytes[i + 4]) >>> 0; // skip LIST/RIFF and get the actual type
+
+    if ((0, _byteHelpers.bytesMatch)(type, CONSTANTS.LIST) || (0, _byteHelpers.bytesMatch)(type, CONSTANTS.RIFF) || (0, _byteHelpers.bytesMatch)(type, CONSTANTS.WAVE)) {
+      type = bytes.subarray(i + 8, i + 12);
+      i += 4;
+      size -= 4;
+    }
+
+    var data = bytes.subarray(i + 8, i + 8 + size);
+
+    if ((0, _byteHelpers.bytesMatch)(type, paths[0])) {
+      if (paths.length === 1) {
+        // this is the end of the path and we've found the box we were
+        // looking for
+        results.push(data);
+      } else {
+        // recursively search for the next box along the path
+        var subresults = findFourCC(data, paths.slice(1));
+
+        if (subresults.length) {
+          results = results.concat(subresults);
+        }
+      }
+    }
+
+    i += 8 + data.length;
+  } // we've finished searching all of bytes
+
+
+  return results;
+};
+
+exports.findFourCC = findFourCC;