perf(golive/spike): binding addTrack + TS port of @dank074 media stack

Phase 1 spike: replace @dank074/discord-video-stream + node-datachannel + node-av (1.3GB) with minimal libdatachannel N-API binding + native RTP packetizers (H264 FU-A, RTCP SR/NACK, pacer) + pure-TS GoLive stack. Binding v0.4: addTrack (m=audio/video SDP), TrackWrap w/ setPacketizer + sendFrame (raw RTP to transport) + addTimestamp — verified by two-peer handshake emitting SDP with audio(opus 120)+video(H264 101) and 8-frame RTP roundtrip. TS layer (src/goLive/, 21 files): CodecPayloadType, VoiceOpCodes, GatewayOpCodes, utils, BaseMediaConnection (voice WS + DAVE + heartbeat), VoiceConnection, StreamConnection, Streamer, WebRtcWrapper (SDP mungling, DAVE encrypt, packetizer chain), BaseMediaStream (pacing/sync), VideoStream, AudioStream, Demuxer (ffmpeg-spawn NUT/AnnexB, no node-av 114M binary), Encoders, prepareStream/playStream. Integration: screenShareController.ts now imports from ../../goLive/index.js — prepareStream(prepared, ...) + playStream(prepared, streamer, {...}). Tests: tests/goLive-port.test.ts (8/8 pass). tsc --noEmit clean. biome clean.
2026-08-11 16:16:52 +07:00
parent a1a6d8b418
commit 9ae230d047
22 changed files with 3026 additions and 17 deletions
@@ -0,0 +1,155 @@
+/**
+ * AnnexB bitstream reader/writer (RBSP + emulation prevention) — ported
+ * from @dank074/discord-video-stream AnnexBBitstreamReaderWriter.js.
+ */
+
+export class AnnexBBitstreamReader {
+  private _buffer: Uint8Array;
+  private _byteOffset = 0;
+  private _bitOffset = 0;
+
+  constructor(buffer: Uint8Array) {
+    this._buffer = buffer;
+  }
+
+  readBits(count: number): number {
+    if (count === 0) return 0;
+    let result = 0;
+    while (count > 0) {
+      if (this._byteOffset >= this._buffer.length) {
+        throw new Error("Bad byte offset");
+      }
+      if (
+        this._bitOffset === 0 &&
+        this._byteOffset >= 2 &&
+        this._buffer[this._byteOffset - 2] === 0 &&
+        this._buffer[this._byteOffset - 1] === 0 &&
+        this._buffer[this._byteOffset] === 3
+      ) {
+        // Skip over emulation prevention
+        this._byteOffset++;
+      }
+      if (this._bitOffset === 0 && count >= 8) {
+        result = (result << 8) | this._buffer[this._byteOffset++];
+        count -= 8;
+      } else {
+        const numBitsToRead = Math.min(count, 8 - this._bitOffset);
+        const mask = (1 << numBitsToRead) - 1;
+        const newBits =
+          (this._buffer[this._byteOffset] >>
+            (8 - this._bitOffset - numBitsToRead)) &
+          mask;
+        result = (result << numBitsToRead) | newBits;
+        count -= numBitsToRead;
+        this._bitOffset += numBitsToRead;
+        if (this._bitOffset === 8) {
+          this._bitOffset = 0;
+          this._byteOffset++;
+        }
+      }
+    }
+    return result;
+  }
+
+  readUnsigned(bits: number): number {
+    return this.readBits(bits);
+  }
+
+  readSigned(bits: number): number {
+    const unsigned = this.readUnsigned(bits);
+    if (unsigned & (1 << (bits - 1))) return unsigned - (1 << bits);
+    return unsigned;
+  }
+
+  readUnsignedExpGolomb(): number {
+    let leading0 = 0;
+    while (this.readBits(1) === 0) leading0++;
+    return (1 << leading0) + this.readBits(leading0) - 1;
+  }
+
+  readSignedExpGolomb(): number {
+    const unsigned = this.readUnsignedExpGolomb();
+    if (unsigned % 2 === 0) return unsigned / -2;
+    return (unsigned + 1) / 2;
+  }
+}
+
+export class AnnexBBitstreamWriter {
+  private _arr: number[] = [];
+  private _pendingByte = 0;
+  private _bitOffset = 0;
+
+  toBuffer(): Buffer {
+    return Buffer.from(this._arr);
+  }
+
+  flush(): void {
+    // Emulation prevention: insert 0x03 before 00 00
+    if (
+      this._pendingByte <= 3 &&
+      this._arr[this._arr.length - 1] === 0 &&
+      this._arr[this._arr.length - 2] === 0
+    ) {
+      this._arr.push(3);
+    }
+    this._arr.push(this._pendingByte);
+    this._pendingByte = 0;
+    this._bitOffset = 0;
+  }
+
+  writeBits(bits: number, count: number): void {
+    while (count > 0) {
+      if (this._bitOffset === 0) {
+        if (count >= 8) {
+          this._pendingByte = (bits >> (count - 8)) & 0xff;
+          count -= 8;
+          this.flush();
+        } else {
+          const mask = (1 << count) - 1;
+          this._pendingByte |= (bits & mask) << (8 - count);
+          this._bitOffset = count;
+          count = 0;
+        }
+      } else {
+        const numBitsToWrite = Math.min(8 - this._bitOffset, count);
+        const bitsToWrite =
+          (bits >> (count - numBitsToWrite)) & ((1 << numBitsToWrite) - 1);
+        this._pendingByte |=
+          bitsToWrite << (8 - this._bitOffset - numBitsToWrite);
+        count -= numBitsToWrite;
+        this._bitOffset += numBitsToWrite;
+        if (this._bitOffset === 8) {
+          this._bitOffset = 0;
+          this.flush();
+        }
+      }
+    }
+  }
+
+  writeUnsigned(num: number, count: number): void {
+    if (num < 0) throw new Error("Expected a non-negative number");
+    this.writeBits(num, count);
+  }
+
+  writeSigned(num: number, count: number): void {
+    if (count <= 0) return;
+    if (count > 32) throw new Error("writeSigned supports up to 32 bits");
+    const mask =
+      count === 32 ? 0xffffffff >>> 0 : (((1 << count) >>> 0) - 1) >>> 0;
+    const unsigned = (num & mask) >>> 0;
+    this.writeBits(unsigned, count);
+  }
+
+  writeUnsignedExpGolomb(num: number): void {
+    if (num < 0) throw new Error("Expected a non-negative number");
+    num++;
+    const bitCount = 32 - Math.clz32(num >>> 0);
+    this.writeBits(0, bitCount - 1);
+    this.writeBits(num, bitCount);
+  }
+
+  writeSignedExpGolomb(num: number): void {
+    if (num < 0) this.writeUnsignedExpGolomb(-2 * num);
+    else this.writeUnsignedExpGolomb(2 * num - 1);
+  }
+}