diff --git a/services/discord-gateway/native/libdatachannel-min/test-rtp-capture.js b/services/discord-gateway/native/libdatachannel-min/test-rtp-capture.js
new file mode 100644
index 0000000..c6a4c5a
--- /dev/null
+++ b/services/discord-gateway/native/libdatachannel-min/test-rtp-capture.js
@@ -0,0 +1,138 @@
+// Two-peer RTP capture test: A sends REAL H264 frames through the binding's
+// packetizer chain to B over localhost. tcpdump (run externally on lo) captures
+// the RTP; a Python script reassembles AnnexB and ffmpeg decodes it.
+//
+// Usage:
+//   node test-rtp-capture.js <mode>   mode = "a" (sender) | "b" (receiver)
+//   Sender writes the negotiated SDP pieces to /tmp/rtp-a.sdp /tmp/rtp-b.sdp
+//   Receiver listens and keeps alive.
+"use strict";
+const { PeerConnection } = require("./build/Release/datachannel_min.node");
+const fs = require("fs");
+
+const mode = process.argv[2] || "a";
+const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
+
+async function main() {
+  const pc = new PeerConnection({ iceServers: [] });
+  const audio = pc.addTrack("0", "audio");
+  const video = pc.addTrack("1", "video");
+
+  if (mode === "a") {
+    // Sender: generate offer, hand to B via files, get B's answer
+    const offer = await pc.createOffer();
+    fs.writeFileSync("/tmp/rtp-offer.sdp", offer);
+    console.log("[a] offer written", offer.length, "bytes");
+
+    // wait for B to write its answer
+    for (let i = 0; i < 300; i++) {
+      if (fs.existsSync("/tmp/rtp-answer.sdp")) break;
+      await sleep(200);
+    }
+    const answer = fs.readFileSync("/tmp/rtp-answer.sdp", "utf8");
+    pc.setRemoteDescription(answer, "answer");
+
+    // wait connected
+    for (let i = 0; i < 50; i++) {
+      if (pc.state() === "connected") break;
+      await sleep(100);
+    }
+    console.log("[a] state:", pc.state());
+    if (pc.state() !== "connected") {
+      console.log("[a] FAILED not connected");
+      process.exit(1);
+    }
+
+    // Setup packetizer like the gateway does
+    video.setPacketizer("h264", 5678, 101, 90000, 5, 0, 10);
+
+    // Real H264 AnnexB (baseline) — read from file created by ffmpeg
+    const data = fs.readFileSync("/tmp/rtp-input.h264");
+    console.log("[a] input h264 bytes:", data.length);
+
+    // Split into NAL units by start codes, then group into access units
+    // the same way Demuxer does (param sets + one slice per frame).
+    const start3 = Buffer.from([0, 0, 1]);
+    const start4 = Buffer.from([0, 0, 0, 1]);
+    const nals = [];
+    let i = 0;
+    while (i < data.length) {
+      let start = -1;
+      let startLen = 0;
+      for (let j = i; j < data.length - 3; j++) {
+        if (data[j] === 0 && data[j + 1] === 0 && data[j + 2] === 1) {
+          start = j;
+          startLen = 3;
+          if (j > 0 && data[j - 1] === 0) {
+            start = j - 1;
+            startLen = 4;
+          }
+          break;
+        }
+      }
+      if (start === -1) break;
+      if (start > i) {
+        nals.push(data.subarray(i, start));
+      }
+      i = start + startLen;
+    }
+    console.log("[a] NALs:", nals.length);
+
+    // Group: buffer param sets, flush on slice (like Demuxer.flushAccessUnit)
+    let pending = [];
+    let frameCount = 0;
+    const flush = () => {
+      if (pending.length === 0) return;
+      const parts = pending.map((n) => Buffer.concat([start4, n]));
+      const au = Buffer.concat(parts);
+      pending = [];
+      video.sendFrame(au);
+      video.addTimestamp(3000); // 30fps @ 90kHz
+      frameCount++;
+    };
+    for (const n of nals) {
+      const t = n[0] & 0x1f;
+      if (t === 1 || t === 5) {
+        flush(); // previous AU closed by this slice
+        pending.push(n);
+      } else {
+        pending.push(n); // param set / SEI
+      }
+    }
+    flush();
+    console.log("[a] sent frames:", frameCount);
+    await sleep(3000); // let packets flow
+    console.log("[a] done");
+    pc.close();
+    process.exit(0);
+  } else {
+    // Receiver: read offer, answer, keep alive
+    for (let i = 0; i < 300; i++) {
+      if (fs.existsSync("/tmp/rtp-offer.sdp")) break;
+      await sleep(200);
+    }
+    const offer = fs.readFileSync("/tmp/rtp-offer.sdp", "utf8");
+    pc.setRemoteDescription(offer, "offer");
+    const answer = await pc.createAnswer(offer);
+    fs.writeFileSync("/tmp/rtp-answer.sdp", answer);
+    console.log("[b] answer written");
+    for (let i = 0; i < 50; i++) {
+      if (pc.state() === "connected") break;
+      await sleep(100);
+    }
+    console.log("[b] state:", pc.state());
+    await sleep(10000); // hold while sender streams
+    console.log("[b] done");
+    pc.close();
+    process.exit(0);
+  }
+}
+
+main().catch((e) => {
+  console.error("FAILED:", e.message);
+  process.exit(1);
+});
+setTimeout(() => {
+  console.error("TIMEOUT");
+  process.exit(1);
+}, 30000);
diff --git a/services/discord-gateway/tests/golive-demux-live-e2e.ts b/services/discord-gateway/tests/golive-demux-live-e2e.ts
index 20da726..8dd8f63 100644
--- a/services/discord-gateway/tests/golive-demux-live-e2e.ts
+++ b/services/discord-gateway/tests/golive-demux-live-e2e.ts
@@ -17,10 +17,22 @@ await new Promise<void>((resolve, reject) => {
   const p = spawn(
     FFMPEG,
     [
-      "-hide_banner", "-loglevel", "error",
-      "-f", "lavfi", "-i", "testsrc=size=640x360:rate=30:duration=2",
-      "-c:v", "libx264", "-preset", "ultrafast", "-pix_fmt", "yuv420p",
-      "-f", "h264", clip,
+      "-hide_banner",
+      "-loglevel",
+      "error",
+      "-f",
+      "lavfi",
+      "-i",
+      "testsrc=size=640x360:rate=30:duration=2",
+      "-c:v",
+      "libx264",
+      "-preset",
+      "ultrafast",
+      "-pix_fmt",
+      "yuv420p",
+      "-f",
+      "h264",
+      clip,
     ],
     { stdio: ["ignore", "ignore", "pipe"] },
   );
@@ -95,7 +107,10 @@ for (const f of frames) {
   const hasParams = types.some((t) => t === 7 || t === 8);
   const isKey = (f.flags & 1) !== 0;
   if (!hasSlice) framesWithoutSlice++;
-  if (types.length === 1 && (types[0] === 7 || types[0] === 8 || types[0] === 6)) {
+  if (
+    types.length === 1 &&
+    (types[0] === 7 || types[0] === 8 || types[0] === 6)
+  ) {
     bareParamSetFrames++;
   }
   if (isKey && hasParams) keyframesWithParamSets++;
@@ -106,20 +121,28 @@ console.log(
   `metadata: ${video.codecName} ${video.width}x${video.height} fps=${video.framerate_num}/${video.framerate_den}`,
 );
 console.log(`frames while stream OPEN (not ended): ${frames.length}`);
-console.log(`frames w/o slice NAL: ${framesWithoutSlice}, bare param-set frames: ${bareParamSetFrames}`);
-console.log(`keyframes with SPS/PPS: ${keyframesWithParamSets}, without: ${keyframesWithoutParamSets}`);
+console.log(
+  `frames w/o slice NAL: ${framesWithoutSlice}, bare param-set frames: ${bareParamSetFrames}`,
+);
+console.log(
+  `keyframes with SPS/PPS: ${keyframesWithParamSets}, without: ${keyframesWithoutParamSets}`,
+);
 if (frames.length === 0) {
   console.error("FAIL: no frames emitted while input still open (deadlock)");
   close();
   process.exit(1);
 }
 if (bareParamSetFrames > 0 || framesWithoutSlice > 0) {
-  console.error("FAIL: demux emitted bare parameter-set frames (must group into access units)");
+  console.error(
+    "FAIL: demux emitted bare parameter-set frames (must group into access units)",
+  );
   close();
   process.exit(1);
 }
 if (frames.some((f) => f.duration !== 1 || f.timeBase.den !== 30)) {
-  console.error("FAIL: frame duration/timeBase not 1/30 (RTP timestamp advance wrong)");
+  console.error(
+    "FAIL: frame duration/timeBase not 1/30 (RTP timestamp advance wrong)",
+  );
   close();
   process.exit(1);
 }