ffmpeg: allow import in nodejs (#577)

* Add empty node module

* Switch to empty.mts

packages/ffmpeg/package.json

@@ -7,8 +7,11 @@
   "exports": {
     ".": {
       "types": "./dist/esm/index.d.ts",
-      "import": "./dist/esm/index.js",
-      "require": "./dist/umd/ffmpeg.js"
+      "node": "./dist/esm/empty.mjs",
+      "default": {
+        "import": "./dist/esm/index.js",
+        "require": "./dist/umd/ffmpeg.js"
+      }
     }
   },
   "scripts": {

packages/ffmpeg/src/empty.mts

@@ -0,0 +1,7 @@
+// File to be imported in node enviroments
+
+export class FFmpeg {
+  constructor() {
+    throw new Error("ffmpeg.wasm does not support nodejs");
+  }
+}