From 275296eda7558f319819a959b6d0b1b3da18fada Mon Sep 17 00:00:00 2001
From: xin <98406118+9c5s@users.noreply.github.com>
Date: Sun, 12 Apr 2026 02:03:09 +0900
Subject: [PATCH] =?UTF-8?q?fix:=20pitchBend=E3=82=92=E7=AC=A6=E5=8F=B7?=
 =?UTF-8?q?=E4=BB=98=E3=81=8D16bit=E3=81=A7=E8=AA=AD=E3=81=BF=E5=8F=96?=
 =?UTF-8?q?=E3=82=8B?=
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readUInt16LEをreadInt16LEに変更し、負のピッチ値が
65536加算された不正な値として返される問題を修正する
---
 .changeset/fix-pitch-bend-signed.md |  7 +++++++
 src/network.ts                      |  2 +-
 tests/packet-parsers.test.ts        | 14 ++++++++------
 3 files changed, 16 insertions(+), 7 deletions(-)
 create mode 100644 .changeset/fix-pitch-bend-signed.md

diff --git a/.changeset/fix-pitch-bend-signed.md b/.changeset/fix-pitch-bend-signed.md
new file mode 100644
index 0000000..64b767b
--- /dev/null
+++ b/.changeset/fix-pitch-bend-signed.md
@@ -0,0 +1,7 @@
+---
+"@9c5s/node-tcnet": patch
+---
+
+pitchBendを符号付き16bitで読み取るよう修正
+
+`readUInt16LE`を`readInt16LE`に変更し、負のピッチ値が正しく負の数値として返されるようにした。
diff --git a/src/network.ts b/src/network.ts
index 26b4dc2..9ad0639 100644
--- a/src/network.ts
+++ b/src/network.ts
@@ -574,7 +574,7 @@ export class TCNetDataPacketMetrics extends TCNetDataPacket {
             speed: this.buffer.readUInt32LE(40),
             beatNumber: this.buffer.readUInt32LE(57),
             bpm: this.buffer.readUInt32LE(112),
-            pitchBend: this.buffer.readUInt16LE(116),
+            pitchBend: this.buffer.readInt16LE(116),
             trackID: this.buffer.readUInt32LE(118),
         };
     }
diff --git a/tests/packet-parsers.test.ts b/tests/packet-parsers.test.ts
index 0930cff..6618833 100644
--- a/tests/packet-parsers.test.ts
+++ b/tests/packet-parsers.test.ts
@@ -544,7 +544,7 @@ describe("TCNetDataPacketMetrics", () => {
         buffer.writeUInt32LE(100000, 40); // speed
         buffer.writeUInt32LE(4, 57); // beatNumber
         buffer.writeUInt32LE(14000, 112); // bpm (= 140.00 BPM * 100)
-        buffer.writeUInt16LE(40000, 116); // pitchBend (32768=100%)
+        buffer.writeInt16LE(600, 116); // pitchBend (+6.00%)
         buffer.writeUInt32LE(777, 118); // trackID
 
         const packet = new TCNetDataPacketMetrics();
@@ -564,7 +564,7 @@ describe("TCNetDataPacketMetrics", () => {
         expect(packet.data!.speed).toBe(100000);
         expect(packet.data!.beatNumber).toBe(4);
         expect(packet.data!.bpm).toBe(14000);
-        expect(packet.data!.pitchBend).toBe(40000);
+        expect(packet.data!.pitchBend).toBe(600);
         expect(packet.data!.trackID).toBe(777);
     });
 
@@ -580,9 +580,11 @@ describe("TCNetDataPacketMetrics", () => {
     });
 
     it.each([
-        { value: 0, label: "最小値" },
-        { value: 32768, label: "100%基準" },
-        { value: 65535, label: "最大値" },
+        { value: 0, label: "ピッチ変更なし" },
+        { value: 600, label: "+6.00%" },
+        { value: -600, label: "-6.00%" },
+        { value: 32767, label: "最大値" },
+        { value: -32768, label: "最小値" },
     ])("pitchBend=$value ($label) を正しくパースする", ({ value }) => {
         const buffer = Buffer.alloc(122);
         buffer.writeUInt8(3, 2);
@@ -590,7 +592,7 @@ describe("TCNetDataPacketMetrics", () => {
         buffer.writeUInt8(200, 7);
         buffer.writeUInt8(2, 24);
         buffer.writeUInt8(1, 25);
-        buffer.writeUInt16LE(value, 116);
+        buffer.writeInt16LE(value, 116);
         const packet = new TCNetDataPacketMetrics();
         packet.buffer = buffer;
         packet.header = createHeader(buffer);