DMUS_REGION

using System;
using System.Runtime.InteropServices;

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct RGNRANGE
{
    public ushort usLow;
    public ushort usHigh;
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct WAVELINK
{
    public ushort fusOptions;
    public ushort usPhaseGroup;
    public uint ulChannel;
    public uint ulTableIndex;
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct WSMPL
{
    public uint cbSize;
    public ushort usUnityNote;
    public short sFineTune;
    public int lAttenuation;
    public uint fulOptions;
    public uint cSampleLoops;
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct WLOOP
{
    public uint cbSize;
    public uint ulType;
    public uint ulStart;
    public uint ulLength;
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct DMUS_REGION
{
    public RGNRANGE RangeKey;
    public RGNRANGE RangeVelocity;
    public ushort fusOptions;
    public ushort usKeyGroup;
    public uint ulRegionArtIdx;
    public uint ulNextRegionIdx;
    public uint ulFirstExtCkIdx;
    public WAVELINK WaveLink;
    public WSMPL WSMP;
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 1)] public WLOOP[] WLOOP;
}

Imports System.Runtime.InteropServices

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure RGNRANGE
    Public usLow As UShort
    Public usHigh As UShort
End Structure

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure WAVELINK
    Public fusOptions As UShort
    Public usPhaseGroup As UShort
    Public ulChannel As UInteger
    Public ulTableIndex As UInteger
End Structure

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure WSMPL
    Public cbSize As UInteger
    Public usUnityNote As UShort
    Public sFineTune As Short
    Public lAttenuation As Integer
    Public fulOptions As UInteger
    Public cSampleLoops As UInteger
End Structure

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure WLOOP
    Public cbSize As UInteger
    Public ulType As UInteger
    Public ulStart As UInteger
    Public ulLength As UInteger
End Structure

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure DMUS_REGION
    Public RangeKey As RGNRANGE
    Public RangeVelocity As RGNRANGE
    Public fusOptions As UShort
    Public usKeyGroup As UShort
    Public ulRegionArtIdx As UInteger
    Public ulNextRegionIdx As UInteger
    Public ulFirstExtCkIdx As UInteger
    Public WaveLink As WAVELINK
    Public WSMP As WSMPL
    <MarshalAs(UnmanagedType.ByValArray, SizeConst:=1)> Public WLOOP() As WLOOP
End Structure

import ctypes
from ctypes import wintypes

class RGNRANGE(ctypes.Structure):
    _fields_ = [
        ("usLow", ctypes.c_ushort),
        ("usHigh", ctypes.c_ushort),
    ]

class WAVELINK(ctypes.Structure):
    _fields_ = [
        ("fusOptions", ctypes.c_ushort),
        ("usPhaseGroup", ctypes.c_ushort),
        ("ulChannel", wintypes.DWORD),
        ("ulTableIndex", wintypes.DWORD),
    ]

class WSMPL(ctypes.Structure):
    _fields_ = [
        ("cbSize", wintypes.DWORD),
        ("usUnityNote", ctypes.c_ushort),
        ("sFineTune", ctypes.c_short),
        ("lAttenuation", ctypes.c_int),
        ("fulOptions", wintypes.DWORD),
        ("cSampleLoops", wintypes.DWORD),
    ]

class WLOOP(ctypes.Structure):
    _fields_ = [
        ("cbSize", wintypes.DWORD),
        ("ulType", wintypes.DWORD),
        ("ulStart", wintypes.DWORD),
        ("ulLength", wintypes.DWORD),
    ]

class DMUS_REGION(ctypes.Structure):
    _fields_ = [
        ("RangeKey", RGNRANGE),
        ("RangeVelocity", RGNRANGE),
        ("fusOptions", ctypes.c_ushort),
        ("usKeyGroup", ctypes.c_ushort),
        ("ulRegionArtIdx", wintypes.DWORD),
        ("ulNextRegionIdx", wintypes.DWORD),
        ("ulFirstExtCkIdx", wintypes.DWORD),
        ("WaveLink", WAVELINK),
        ("WSMP", WSMPL),
        ("WLOOP", WLOOP * 1),
    ]

#[repr(C)]
pub struct RGNRANGE {
    pub usLow: u16,
    pub usHigh: u16,
}

#[repr(C)]
pub struct WAVELINK {
    pub fusOptions: u16,
    pub usPhaseGroup: u16,
    pub ulChannel: u32,
    pub ulTableIndex: u32,
}

#[repr(C)]
pub struct WSMPL {
    pub cbSize: u32,
    pub usUnityNote: u16,
    pub sFineTune: i16,
    pub lAttenuation: i32,
    pub fulOptions: u32,
    pub cSampleLoops: u32,
}

#[repr(C)]
pub struct WLOOP {
    pub cbSize: u32,
    pub ulType: u32,
    pub ulStart: u32,
    pub ulLength: u32,
}

#[repr(C)]
pub struct DMUS_REGION {
    pub RangeKey: RGNRANGE,
    pub RangeVelocity: RGNRANGE,
    pub fusOptions: u16,
    pub usKeyGroup: u16,
    pub ulRegionArtIdx: u32,
    pub ulNextRegionIdx: u32,
    pub ulFirstExtCkIdx: u32,
    pub WaveLink: WAVELINK,
    pub WSMP: WSMPL,
    pub WLOOP: [WLOOP; 1],
}

import "golang.org/x/sys/windows"

type RGNRANGE struct {
	usLow uint16
	usHigh uint16
}

type WAVELINK struct {
	fusOptions uint16
	usPhaseGroup uint16
	ulChannel uint32
	ulTableIndex uint32
}

type WSMPL struct {
	cbSize uint32
	usUnityNote uint16
	sFineTune int16
	lAttenuation int32
	fulOptions uint32
	cSampleLoops uint32
}

type WLOOP struct {
	cbSize uint32
	ulType uint32
	ulStart uint32
	ulLength uint32
}

type DMUS_REGION struct {
	RangeKey RGNRANGE
	RangeVelocity RGNRANGE
	fusOptions uint16
	usKeyGroup uint16
	ulRegionArtIdx uint32
	ulNextRegionIdx uint32
	ulFirstExtCkIdx uint32
	WaveLink WAVELINK
	WSMP WSMPL
	WLOOP [1]WLOOP
}

type
  RGNRANGE = record
    usLow: Word;
    usHigh: Word;
  end;

  WAVELINK = record
    fusOptions: Word;
    usPhaseGroup: Word;
    ulChannel: DWORD;
    ulTableIndex: DWORD;
  end;

  WSMPL = record
    cbSize: DWORD;
    usUnityNote: Word;
    sFineTune: Smallint;
    lAttenuation: Integer;
    fulOptions: DWORD;
    cSampleLoops: DWORD;
  end;

  WLOOP = record
    cbSize: DWORD;
    ulType: DWORD;
    ulStart: DWORD;
    ulLength: DWORD;
  end;

  DMUS_REGION = record
    RangeKey: RGNRANGE;
    RangeVelocity: RGNRANGE;
    fusOptions: Word;
    usKeyGroup: Word;
    ulRegionArtIdx: DWORD;
    ulNextRegionIdx: DWORD;
    ulFirstExtCkIdx: DWORD;
    WaveLink: WAVELINK;
    WSMP: WSMPL;
    WLOOP: array[0..0] of WLOOP;
  end;

const RGNRANGE = extern struct {
    usLow: u16,
    usHigh: u16,
};

const WAVELINK = extern struct {
    fusOptions: u16,
    usPhaseGroup: u16,
    ulChannel: u32,
    ulTableIndex: u32,
};

const WSMPL = extern struct {
    cbSize: u32,
    usUnityNote: u16,
    sFineTune: i16,
    lAttenuation: i32,
    fulOptions: u32,
    cSampleLoops: u32,
};

const WLOOP = extern struct {
    cbSize: u32,
    ulType: u32,
    ulStart: u32,
    ulLength: u32,
};

const DMUS_REGION = extern struct {
    RangeKey: RGNRANGE,
    RangeVelocity: RGNRANGE,
    fusOptions: u16,
    usKeyGroup: u16,
    ulRegionArtIdx: u32,
    ulNextRegionIdx: u32,
    ulFirstExtCkIdx: u32,
    WaveLink: WAVELINK,
    WSMP: WSMPL,
    WLOOP: [1]WLOOP,
};

type
  RGNRANGE {.bycopy.} = object
    usLow: uint16
    usHigh: uint16

  WAVELINK {.bycopy.} = object
    fusOptions: uint16
    usPhaseGroup: uint16
    ulChannel: uint32
    ulTableIndex: uint32

  WSMPL {.bycopy.} = object
    cbSize: uint32
    usUnityNote: uint16
    sFineTune: int16
    lAttenuation: int32
    fulOptions: uint32
    cSampleLoops: uint32

  WLOOP {.bycopy.} = object
    cbSize: uint32
    ulType: uint32
    ulStart: uint32
    ulLength: uint32

  DMUS_REGION {.bycopy.} = object
    RangeKey: RGNRANGE
    RangeVelocity: RGNRANGE
    fusOptions: uint16
    usKeyGroup: uint16
    ulRegionArtIdx: uint32
    ulNextRegionIdx: uint32
    ulFirstExtCkIdx: uint32
    WaveLink: WAVELINK
    WSMP: WSMPL
    WLOOP: array[1, WLOOP]

struct RGNRANGE
{
    ushort usLow;
    ushort usHigh;
}

struct WAVELINK
{
    ushort fusOptions;
    ushort usPhaseGroup;
    uint ulChannel;
    uint ulTableIndex;
}

struct WSMPL
{
    uint cbSize;
    ushort usUnityNote;
    short sFineTune;
    int lAttenuation;
    uint fulOptions;
    uint cSampleLoops;
}

struct WLOOP
{
    uint cbSize;
    uint ulType;
    uint ulStart;
    uint ulLength;
}

struct DMUS_REGION
{
    RGNRANGE RangeKey;
    RGNRANGE RangeVelocity;
    ushort fusOptions;
    ushort usKeyGroup;
    uint ulRegionArtIdx;
    uint ulNextRegionIdx;
    uint ulFirstExtCkIdx;
    WAVELINK WaveLink;
    WSMPL WSMP;
    WLOOP[1] WLOOP;
}