Add @mediabunny/ac3 extension package

packages/ac3/src/index.ts

@@ -0,0 +1,21 @@
+/*!
+ * Copyright (c) 2026-present, Vanilagy and contributors
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+const AC3_LOADED_SYMBOL = Symbol.for('@mediabunny/ac3 loaded');
+if ((globalThis as Record<symbol, unknown>)[AC3_LOADED_SYMBOL]) {
+	console.error(
+		'[WARNING]\n@mediabunny/ac3 was loaded twice.'
+		+ ' This will likely cause the encoder/decoder not to work correctly.'
+		+ ' Check if multiple dependencies are importing different versions of @mediabunny/ac3,'
+		+ ' or if something is being bundled incorrectly.',
+	);
+}
+(globalThis as Record<symbol, unknown>)[AC3_LOADED_SYMBOL] = true;
+
+export { registerAc3Decoder } from './decoder';
+export { registerAc3Encoder } from './encoder';