feat: add streaming demuxer tests and implement dual-stream output piping in streaming service

test_stream.ts

@@ -0,0 +1,18 @@
+import { prepareStream } from "@dank074/discord-video-stream";
+import { demux } from "@dank074/discord-video-stream/dist/media/LibavDemuxer.js";
+import { Encoders } from "@dank074/discord-video-stream/dist/media/encoders/index.js";
+
+async function run() {
+  const { command, output } = prepareStream("http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4", {
+    encoder: Encoders.software(),
+    width: 1280,
+    height: 720,
+    includeAudio: true
+  });
+
+  const { video, audio } = await demux(output, { format: "nut" });
+  console.log("Video found:", !!video);
+  console.log("Audio found:", !!audio);
+  process.exit(0);
+}
+run();