mmioSetBuffer

// WINMM.dll
#include <windows.h>

DWORD mmioSetBuffer(
    HMMIO hmmio,
    LPSTR pchBuffer,   // optional
    INT cchBuffer,
    DWORD fuBuffer
);

<DllImport("WINMM.dll", ExactSpelling:=True)>
Public Shared Function mmioSetBuffer(
    hmmio As IntPtr,   ' HMMIO
    <MarshalAs(UnmanagedType.LPStr)> pchBuffer As System.Text.StringBuilder,   ' LPSTR optional, out
    cchBuffer As Integer,   ' INT
    fuBuffer As UInteger   ' DWORD
) As UInteger
End Function

' hmmio : HMMIO
' pchBuffer : LPSTR optional, out
' cchBuffer : INT
' fuBuffer : DWORD
Declare PtrSafe Function mmioSetBuffer Lib "winmm" ( _
    ByVal hmmio As LongPtr, _
    ByVal pchBuffer As String, _
    ByVal cchBuffer As Long, _
    ByVal fuBuffer As Long) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

mmioSetBuffer = ctypes.windll.winmm.mmioSetBuffer
mmioSetBuffer.restype = wintypes.DWORD
mmioSetBuffer.argtypes = [
    wintypes.HANDLE,  # hmmio : HMMIO
    wintypes.LPSTR,  # pchBuffer : LPSTR optional, out
    ctypes.c_int,  # cchBuffer : INT
    wintypes.DWORD,  # fuBuffer : DWORD
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('WINMM.dll')
mmioSetBuffer = Fiddle::Function.new(
  lib['mmioSetBuffer'],
  [
    Fiddle::TYPE_VOIDP,  # hmmio : HMMIO
    Fiddle::TYPE_VOIDP,  # pchBuffer : LPSTR optional, out
    Fiddle::TYPE_INT,  # cchBuffer : INT
    -Fiddle::TYPE_INT,  # fuBuffer : DWORD
  ],
  -Fiddle::TYPE_INT)

#[link(name = "winmm")]
extern "system" {
    fn mmioSetBuffer(
        hmmio: *mut core::ffi::c_void,  // HMMIO
        pchBuffer: *mut u8,  // LPSTR optional, out
        cchBuffer: i32,  // INT
        fuBuffer: u32  // DWORD
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("WINMM.dll")]
public static extern uint mmioSetBuffer(IntPtr hmmio, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder pchBuffer, int cchBuffer, uint fuBuffer);
"@
$api = Add-Type -MemberDefinition $sig -Name 'WINMM_mmioSetBuffer' -Namespace Win32 -PassThru
# $api::mmioSetBuffer(hmmio, pchBuffer, cchBuffer, fuBuffer)

#uselib "WINMM.dll"
#func global mmioSetBuffer "mmioSetBuffer" sptr, sptr, sptr, sptr
; mmioSetBuffer hmmio, varptr(pchBuffer), cchBuffer, fuBuffer   ; 戻り値は stat
; hmmio : HMMIO -> "sptr"
; pchBuffer : LPSTR optional, out -> "sptr"
; cchBuffer : INT -> "sptr"
; fuBuffer : DWORD -> "sptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "WINMM.dll"
#cfunc global mmioSetBuffer "mmioSetBuffer" sptr, var, int, int
; res = mmioSetBuffer(hmmio, pchBuffer, cchBuffer, fuBuffer)
; hmmio : HMMIO -> "sptr"
; pchBuffer : LPSTR optional, out -> "var"
; cchBuffer : INT -> "int"
; fuBuffer : DWORD -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; DWORD mmioSetBuffer(HMMIO hmmio, LPSTR pchBuffer, INT cchBuffer, DWORD fuBuffer)
#uselib "WINMM.dll"
#cfunc global mmioSetBuffer "mmioSetBuffer" intptr, var, int, int
; res = mmioSetBuffer(hmmio, pchBuffer, cchBuffer, fuBuffer)
; hmmio : HMMIO -> "intptr"
; pchBuffer : LPSTR optional, out -> "var"
; cchBuffer : INT -> "int"
; fuBuffer : DWORD -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	winmm = windows.NewLazySystemDLL("WINMM.dll")
	procmmioSetBuffer = winmm.NewProc("mmioSetBuffer")
)

// hmmio (HMMIO), pchBuffer (LPSTR optional, out), cchBuffer (INT), fuBuffer (DWORD)
r1, _, err := procmmioSetBuffer.Call(
	uintptr(hmmio),
	uintptr(pchBuffer),
	uintptr(cchBuffer),
	uintptr(fuBuffer),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function mmioSetBuffer(
  hmmio: THandle;   // HMMIO
  pchBuffer: PAnsiChar;   // LPSTR optional, out
  cchBuffer: Integer;   // INT
  fuBuffer: DWORD   // DWORD
): DWORD; stdcall;
  external 'WINMM.dll' name 'mmioSetBuffer';

result := DllCall("WINMM\mmioSetBuffer"
    , "Ptr", hmmio   ; HMMIO
    , "Ptr", pchBuffer   ; LPSTR optional, out
    , "Int", cchBuffer   ; INT
    , "UInt", fuBuffer   ; DWORD
    , "UInt")   ; return: DWORD

●mmioSetBuffer(hmmio, pchBuffer, cchBuffer, fuBuffer) = DLL("WINMM.dll", "dword mmioSetBuffer(void*, char*, int, dword)")
# 呼び出し: mmioSetBuffer(hmmio, pchBuffer, cchBuffer, fuBuffer)
# hmmio : HMMIO -> "void*"
# pchBuffer : LPSTR optional, out -> "char*"
# cchBuffer : INT -> "int"
# fuBuffer : DWORD -> "dword"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。