From 1649f91318f2d4898d80bc494600274bdbd2a5cf Mon Sep 17 00:00:00 2001
From: AskaEth <i@yeij.top>
Date: Sat, 25 Jul 2026 16:19:53 +0800
Subject: [PATCH] fix: correct Forza FH5/FH6 UDP packet parser offsets per
 official spec
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Speed: offset 256 (m/s * 3.6 = km/h), was incorrectly at 244 (PositionX)
- Gear: offset 319 (U8), was at 264/298
- Throttle/Brake: offsets 315/316 (U8, 0-255)
- Steering: offset 320 (S8, -127~127)
- RPM: offset 16 ✓, MaxRPM: offset 8 ✓
- Lap times: BestLap=296, LastLap=300, CurrentLap=304
- LapNumber: offset 312 (U16)
- Boost: 284, Fuel: 288, Position: 244/248/252
- Updated all Forza parsers (FH4, FH5) and fallback parser
- Ref: Forza Data Out official format (324 bytes)
---
 games/builtin/forza_horizon_4/parser.py | 55 ++++++++--------
 games/builtin/forza_horizon_5/parser.py | 84 ++++++++++++++++---------
 server/telemetry/parsers/__init__.py    | 63 ++++++++-----------
 3 files changed, 109 insertions(+), 93 deletions(-)

diff --git a/games/builtin/forza_horizon_4/parser.py b/games/builtin/forza_horizon_4/parser.py
index c12e76a..fa1652a 100644
--- a/games/builtin/forza_horizon_4/parser.py
+++ b/games/builtin/forza_horizon_4/parser.py
@@ -15,37 +15,36 @@ class ForzaHorizon4Parser:
         td = TelemetryData(game_id="forza_horizon_4", timestamp=time.time())
         td.raw = {"raw_hex": data.hex(), "length": len(data), "addr": f"{addr[0]}:{addr[1]}"}
 
-        if len(data) < 323:
+        if len(data) < 312:
             return td
 
         try:
-            offset = 12
-            td.rpm = struct.unpack_from("<f", data, 8)[0]
-            td.max_rpm = struct.unpack_from("<f", data, 16)[0]
-            td.horsepower = struct.unpack_from("<f", data, 12)[0]
-            td.torque = struct.unpack_from("<f", data, 20)[0]
-            td.boost = struct.unpack_from("<f", data, 308)[0]
-            td.fuel = struct.unpack_from("<f", data, 312)[0]
-            td.oil_temp = struct.unpack_from("<f", data, 316)[0]
-            td.engine_temp = struct.unpack_from("<f", data, 320)[0]
-            td.speed_mph = struct.unpack_from("<f", data, 244)[0]
-            td.speed_kmh = td.speed_mph * 1.60934
-            td.gear = struct.unpack_from("<B", data, 264)[0]
-            td.best_lap = struct.unpack_from("<f", data, 268)[0]
-            td.last_lap = struct.unpack_from("<f", data, 276)[0]
-            td.lap_time = struct.unpack_from("<f", data, 284)[0]
-            td.lap_number = struct.unpack_from("<H", data, 292)[0]
-            td.position_x = struct.unpack_from("<f", data, 0)[0]
-            td.position_y = struct.unpack_from("<f", data, 4)[0]
-            td.position_z = struct.unpack_from("<f", data, 552)[0]
-            td.acceleration_x = struct.unpack_from("<f", data, 300)[0]
-            td.acceleration_y = struct.unpack_from("<f", data, 304)[0]
-            td.acceleration_z = struct.unpack_from("<f", data, 196)[0]
-            td.throttle = struct.unpack_from("<f", data, 228)[0]
-            td.brake = struct.unpack_from("<f", data, 232)[0]
-            td.steering = struct.unpack_from("<f", data, 204)[0]
-            td.clutch = struct.unpack_from("<f", data, 252)[0]
-            td.handbrake = struct.unpack_from("<f", data, 256)[0]
+            td.raw["is_race_on"] = struct.unpack_from("<i", data, 0)[0]
+            td.max_rpm = struct.unpack_from("<f", data, 8)[0]
+            td.rpm = struct.unpack_from("<f", data, 16)[0]
+            td.acceleration_x = struct.unpack_from("<f", data, 20)[0]
+            td.acceleration_y = struct.unpack_from("<f", data, 24)[0]
+            td.acceleration_z = struct.unpack_from("<f", data, 28)[0]
+            td.position_x = struct.unpack_from("<f", data, 244)[0]
+            td.position_y = struct.unpack_from("<f", data, 248)[0]
+            td.position_z = struct.unpack_from("<f", data, 252)[0]
+            td.speed_kmh = struct.unpack_from("<f", data, 256)[0] * 3.6
+            td.speed_mph = td.speed_kmh * 0.621371
+            td.horsepower = struct.unpack_from("<f", data, 260)[0] / 745.7
+            td.torque = struct.unpack_from("<f", data, 264)[0]
+            td.boost = struct.unpack_from("<f", data, 284)[0]
+            td.fuel = struct.unpack_from("<f", data, 288)[0]
+            td.best_lap = struct.unpack_from("<f", data, 296)[0]
+            td.last_lap = struct.unpack_from("<f", data, 300)[0]
+            td.lap_time = struct.unpack_from("<f", data, 304)[0]
+            td.lap_number = struct.unpack_from("<H", data, 312)[0]
+            td.raw["race_position"] = struct.unpack_from("<B", data, 314)[0]
+            td.throttle = struct.unpack_from("<B", data, 315)[0] / 255.0
+            td.brake = struct.unpack_from("<B", data, 316)[0] / 255.0
+            td.clutch = struct.unpack_from("<B", data, 317)[0] / 255.0
+            td.handbrake = struct.unpack_from("<B", data, 318)[0] / 255.0
+            td.gear = struct.unpack_from("<B", data, 319)[0]
+            td.steering = max(-1.0, min(1.0, struct.unpack_from("<b", data, 320)[0] / 127.0))
         except struct.error:
             pass
 
diff --git a/games/builtin/forza_horizon_5/parser.py b/games/builtin/forza_horizon_5/parser.py
index cf5647e..e85dbe6 100644
--- a/games/builtin/forza_horizon_5/parser.py
+++ b/games/builtin/forza_horizon_5/parser.py
@@ -13,38 +13,66 @@ class ForzaHorizon5Parser:
 
     def parse(self, data: bytes, addr: tuple) -> TelemetryData:
         td = TelemetryData(game_id="forza_horizon_5", timestamp=time.time())
-        td.raw = {"raw_hex": data.hex(), "length": len(data), "addr": f"{addr[0]}:{addr[1]}"}
+        td.raw = {
+            "raw_hex": data.hex(),
+            "length": len(data),
+            "addr": f"{addr[0]}:{addr[1]}",
+        }
 
-        if len(data) < 323:
+        if len(data) < 312:
             return td
 
         try:
-            td.rpm = struct.unpack_from("<f", data, 8)[0]
-            td.max_rpm = struct.unpack_from("<f", data, 16)[0]
-            td.horsepower = struct.unpack_from("<f", data, 12)[0]
-            td.torque = struct.unpack_from("<f", data, 20)[0]
-            td.boost = struct.unpack_from("<f", data, 308)[0]
-            td.fuel = struct.unpack_from("<f", data, 312)[0]
-            td.oil_temp = struct.unpack_from("<f", data, 316)[0]
-            td.engine_temp = struct.unpack_from("<f", data, 320)[0]
-            td.speed_mph = struct.unpack_from("<f", data, 244)[0]
-            td.speed_kmh = td.speed_mph * 1.60934
-            td.gear = struct.unpack_from("<B", data, 264)[0]
-            td.best_lap = struct.unpack_from("<f", data, 268)[0]
-            td.last_lap = struct.unpack_from("<f", data, 276)[0]
-            td.lap_time = struct.unpack_from("<f", data, 284)[0]
-            td.lap_number = struct.unpack_from("<H", data, 292)[0]
-            td.position_x = struct.unpack_from("<f", data, 0)[0]
-            td.position_y = struct.unpack_from("<f", data, 4)[0]
-            td.position_z = struct.unpack_from("<f", data, 552)[0]
-            td.acceleration_x = struct.unpack_from("<f", data, 300)[0]
-            td.acceleration_y = struct.unpack_from("<f", data, 304)[0]
-            td.acceleration_z = struct.unpack_from("<f", data, 196)[0]
-            td.throttle = struct.unpack_from("<f", data, 228)[0]
-            td.brake = struct.unpack_from("<f", data, 232)[0]
-            td.steering = struct.unpack_from("<f", data, 204)[0]
-            td.clutch = struct.unpack_from("<f", data, 252)[0]
-            td.handbrake = struct.unpack_from("<f", data, 256)[0]
+            td.raw["is_race_on"] = struct.unpack_from("<i", data, 0)[0]
+
+            # 引擎
+            td.max_rpm = struct.unpack_from("<f", data, 8)[0]
+            td.rpm = struct.unpack_from("<f", data, 16)[0]
+
+            # 加速度 (m/s²)
+            td.acceleration_x = struct.unpack_from("<f", data, 20)[0]
+            td.acceleration_y = struct.unpack_from("<f", data, 24)[0]
+            td.acceleration_z = struct.unpack_from("<f", data, 28)[0]
+
+            # 位置
+            td.position_x = struct.unpack_from("<f", data, 244)[0]
+            td.position_y = struct.unpack_from("<f", data, 248)[0]
+            td.position_z = struct.unpack_from("<f", data, 252)[0]
+
+            # 速度 (m/s)
+            td.speed_kmh = struct.unpack_from("<f", data, 256)[0] * 3.6
+            td.speed_mph = td.speed_kmh * 0.621371
+
+            # 马力 & 扭矩
+            td.horsepower = struct.unpack_from("<f", data, 260)[0] / 745.7
+            td.torque = struct.unpack_from("<f", data, 264)[0]
+
+            # 增压 & 燃油
+            td.boost = struct.unpack_from("<f", data, 284)[0]
+            td.fuel = struct.unpack_from("<f", data, 288)[0]
+
+            # 圈速
+            td.best_lap = struct.unpack_from("<f", data, 296)[0]
+            td.last_lap = struct.unpack_from("<f", data, 300)[0]
+            td.lap_time = struct.unpack_from("<f", data, 304)[0]
+            td.lap_number = struct.unpack_from("<H", data, 312)[0]
+
+            # 排名
+            td.raw["race_position"] = struct.unpack_from("<B", data, 314)[0]
+
+            # 玩家输入 (U8, 0-255)
+            td.throttle = struct.unpack_from("<B", data, 315)[0] / 255.0
+            td.brake = struct.unpack_from("<B", data, 316)[0] / 255.0
+            td.clutch = struct.unpack_from("<B", data, 317)[0] / 255.0
+            td.handbrake = struct.unpack_from("<B", data, 318)[0] / 255.0
+
+            # 档位
+            td.gear = struct.unpack_from("<B", data, 319)[0]
+
+            # 转向 (-127 ~ 127)
+            td.steering = max(-1.0, min(1.0,
+                struct.unpack_from("<b", data, 320)[0] / 127.0))
+
         except struct.error:
             pass
 
diff --git a/server/telemetry/parsers/__init__.py b/server/telemetry/parsers/__init__.py
index 169deea..e6eebab 100644
--- a/server/telemetry/parsers/__init__.py
+++ b/server/telemetry/parsers/__init__.py
@@ -27,47 +27,36 @@ class ForzaParser(BaseParser):
         td = TelemetryData(game_id=self._format, timestamp=time.time())
         td.raw = {"raw_hex": data.hex(), "length": len(data), "addr": f"{addr[0]}:{addr[1]}"}
 
-        if len(data) < 323:
+        if len(data) < 312:
             logger.warning("Forza data too short: %d bytes", len(data))
             return td
 
         try:
-            if self._format == "fh4":
-                offset = 0
-            else:
-                offset = 0
-
-            td.rpm = struct.unpack_from("<f", data, 8)[0]
-            td.max_rpm = struct.unpack_from("<f", data, 16)[0]
-            td.horsepower = struct.unpack_from("<f", data, 12)[0]
-            td.torque = struct.unpack_from("<f", data, 20)[0]
-
-            td.boost = struct.unpack_from("<f", data, 308)[0]
-            td.fuel = struct.unpack_from("<f", data, 312)[0]
-            td.oil_temp = struct.unpack_from("<f", data, 316)[0]
-            td.engine_temp = struct.unpack_from("<f", data, 320)[0]
-
-            td.speed_mph = struct.unpack_from("<f", data, 244)
-            td.speed_kmh = td.speed_mph * 1.60934
-            td.gear = struct.unpack_from("<B", data, 264)[0]
-            td.best_lap = struct.unpack_from("<f", data, 268)[0]
-            td.last_lap = struct.unpack_from("<f", data, 276)[0]
-            td.lap_time = struct.unpack_from("<f", data, 284)[0]
-            td.lap_number = struct.unpack_from("<H", data, 292)[0]
-
-            td.position_x = struct.unpack_from("<f", data, 0)[0]
-            td.position_y = struct.unpack_from("<f", data, 4)[0]
-            td.position_z = struct.unpack_from("<f", data, 552)[0]
-
-            td.acceleration_x = struct.unpack_from("<f", data, 300)[0]
-            td.acceleration_y = struct.unpack_from("<f", data, 304)[0]
-            td.acceleration_z = struct.unpack_from("<f", data, 196)[0]
-
-            td.throttle = struct.unpack_from("<f", data, 228)[0]
-            td.brake = struct.unpack_from("<f", data, 232)[0]
-            td.steering = struct.unpack_from("<f", data, 204)[0]
-            td.clutch = struct.unpack_from("<f", data, 252)[0]
-            td.handbrake = struct.unpack_from("<f", data, 256)[0]
+            td.raw["is_race_on"] = struct.unpack_from("<i", data, 0)[0]
+            td.rpm = struct.unpack_from("<f", data, 16)[0]
+            td.max_rpm = struct.unpack_from("<f", data, 8)[0]
+            td.horsepower = struct.unpack_from("<f", data, 260)[0] / 745.7
+            td.torque = struct.unpack_from("<f", data, 264)[0]
+            td.boost = struct.unpack_from("<f", data, 284)[0]
+            td.fuel = struct.unpack_from("<f", data, 288)[0]
+            td.speed_kmh = struct.unpack_from("<f", data, 256)[0] * 3.6
+            td.speed_mph = td.speed_kmh * 0.621371
+            td.gear = struct.unpack_from("<B", data, 319)[0]
+            td.best_lap = struct.unpack_from("<f", data, 296)[0]
+            td.last_lap = struct.unpack_from("<f", data, 300)[0]
+            td.lap_time = struct.unpack_from("<f", data, 304)[0]
+            td.lap_number = struct.unpack_from("<H", data, 312)[0]
+            td.position_x = struct.unpack_from("<f", data, 244)[0]
+            td.position_y = struct.unpack_from("<f", data, 248)[0]
+            td.position_z = struct.unpack_from("<f", data, 252)[0]
+            td.acceleration_x = struct.unpack_from("<f", data, 20)[0]
+            td.acceleration_y = struct.unpack_from("<f", data, 24)[0]
+            td.acceleration_z = struct.unpack_from("<f", data, 28)[0]
+            td.throttle = struct.unpack_from("<B", data, 315)[0] / 255.0
+            td.brake = struct.unpack_from("<B", data, 316)[0] / 255.0
+            td.steering = max(-1.0, min(1.0, struct.unpack_from("<b", data, 320)[0] / 127.0))
+            td.clutch = struct.unpack_from("<B", data, 317)[0] / 255.0
+            td.handbrake = struct.unpack_from("<B", data, 318)[0] / 255.0
 
             td.raw.update({
                 "speed_mph": td.speed_mph,