use own mixer

packages/core/src/domains/mcu/lib.ts

@@ -0,0 +1,56 @@
+export class Mixer {
+  inputs: { [id: string]: Input } = {};
+  pcm: { [id: string]: Buffer } = {};
+  onData: (buf: Buffer) => void = () => {};
+
+  constructor(private args: { bit: number }) {}
+
+  input() {
+    const input = new Input(this);
+    this.inputs[input.id] = input;
+
+    return input;
+  }
+
+  mixing() {
+    if (Object.keys(this.pcm).length === Object.keys(this.inputs).length) {
+      const inputs = Object.values(this.pcm);
+      const base = inputs.shift();
+      this.pcm = {};
+      const res = inputs.reduce(
+        (acc: number[], cur) => {
+          const next = acc.map((v, i) => this.mix(v, cur[i]));
+          return next;
+        },
+        [...base]
+      );
+      this.onData(Buffer.from(res));
+    }
+  }
+
+  private mix(a: number, b: number) {
+    const res = a + b;
+    const max = 1 << (this.args.bit - 1);
+    if (max < res) {
+      return max;
+    } else if (0 > res) {
+      return res;
+    }
+    return res;
+  }
+}
+
+export class Input {
+  id = Math.random().toString();
+  constructor(private mixer: Mixer) {}
+
+  write(buf: Buffer) {
+    this.mixer.pcm[this.id] = buf;
+    this.mixer.mixing();
+  }
+
+  remove() {
+    delete this.mixer.inputs[this.id];
+    delete this.mixer.pcm[this.id];
+  }
+}

packages/core/src/domains/mcu/mixer.ts

@@ -1,5 +1,4 @@
 import { OpusEncoder } from "@discordjs/opus";
-import { Input, Mixer } from "../../../../mixer";
 import { performance } from "perf_hooks";
 import { v4 } from "uuid";
 import { RTCRtpTransceiver } from "../../../../werift";
@@ -11,15 +10,13 @@ import {
 } from "../../../../werift/utils";
 import { RtpHeader, RtpPacket } from "../../../../werift/vendor/rtp";
 import { Media } from "../media/media";
-
-const MAX_FRAME_SIZE = (48000 * 60) / 1000;
-const PCM_LENGTH = MAX_FRAME_SIZE * 2 * 2;
+import { Input, Mixer } from "./lib";
 
 export class MCUMixer {
   id = "mix_" + v4();
 
   private encoder = new OpusEncoder(48000, 2);
-  private mixer = new Mixer({ sampleRate: 48000, channels: 2, sleep: 20 });
+  private mixer = new Mixer({ bit: 16 });
   private sequenceNumber = random16();
   private timestamp = random32();
   private now = performance.now();
@@ -34,7 +31,7 @@ export class MCUMixer {
   }
 
   inputMedia(media: Media) {
-    const input = this.mixer.input({ channels: 2, maxBuffer: PCM_LENGTH / 2 });
+    const input = this.mixer.input();
     const { unSubscribe } = media.tracks[0].track.onRtp.subscribe((packet) => {
       if (Object.values(this.disposer)[0].id === media.mediaId) {
         this.header = packet.header;
@@ -51,13 +48,14 @@ export class MCUMixer {
 
   removeMedia = (mediaId: string) => {
     const { stop, input } = this.disposer[mediaId];
-    this.mixer.removeInput(input);
+    input.remove();
     delete this.disposer[mediaId];
     stop();
   };
 
   listen() {
-    this.mixer.on("data", (data) => {
+    this.mixer.onData = (data) => {
+      if (!this.header) return;
       const encoded = this.encoder.encode(data);
 
       this.sequenceNumber = uint16Add(this.sequenceNumber, 1);
@@ -79,7 +77,7 @@ export class MCUMixer {
       });
       const rtp = new RtpPacket(header, encoded);
       this.sender.sendRtp(rtp);
-    });
+    };
   }
 
   close() {