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MPEG1WAVEFORMAT

構造体
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サイズx64: 40 バイト / x86: 40 バイトパッキング1

サイズ=各フィールドのバイト数(x64/x86 で異なる場合は x64/x86 と併記)。x64/x86 列=フィールドのバイトオフセット(HSPで dupptr / lpoke / wpoke 等に使用)。

フィールド

フィールド型サイズx64x86説明
wfxWAVEFORMATEX18+0+0基本波形フォーマット(WAVEFORMATEX)。共通の音声属性を格納する。
fwHeadLayerWORD2+18+18MPEGオーディオのレイヤ(Layer I/II/III)を示すフラグ。
dwHeadBitrateDWORD4+20+20音声のビットレート。単位はビット毎秒(bps)。
fwHeadModeWORD2+24+24チャネルモード(ステレオ・モノ等)を示すフラグ。
fwHeadModeExtWORD2+26+26ジョイントステレオ拡張モードを示すフラグ。
wHeadEmphasisWORD2+28+28エンファシス種別を示す値。
fwHeadFlagsWORD2+30+30MPEGヘッダの各種フラグ(著作権・原本等)。
dwPTSLowDWORD4+32+32提示時刻(PTS)の下位32ビット。
dwPTSHighDWORD4+36+36提示時刻(PTS)の上位ビット(最上位33ビット目)。

各言語での定義

#include <windows.h>

// WAVEFORMATEX  (x64 18 / x86 18 バイト)
#pragma pack(push, 1)
typedef struct WAVEFORMATEX {
    WORD wFormatTag;
    WORD nChannels;
    DWORD nSamplesPerSec;
    DWORD nAvgBytesPerSec;
    WORD nBlockAlign;
    WORD wBitsPerSample;
    WORD cbSize;
} WAVEFORMATEX;
#pragma pack(pop)

// MPEG1WAVEFORMAT  (x64 40 / x86 40 バイト)
#pragma pack(push, 1)
typedef struct MPEG1WAVEFORMAT {
    WAVEFORMATEX wfx;
    WORD fwHeadLayer;
    DWORD dwHeadBitrate;
    WORD fwHeadMode;
    WORD fwHeadModeExt;
    WORD wHeadEmphasis;
    WORD fwHeadFlags;
    DWORD dwPTSLow;
    DWORD dwPTSHigh;
} MPEG1WAVEFORMAT;
#pragma pack(pop)
using System;
using System.Runtime.InteropServices;

[StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Unicode)]
public struct WAVEFORMATEX
{
    public ushort wFormatTag;
    public ushort nChannels;
    public uint nSamplesPerSec;
    public uint nAvgBytesPerSec;
    public ushort nBlockAlign;
    public ushort wBitsPerSample;
    public ushort cbSize;
}

[StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Unicode)]
public struct MPEG1WAVEFORMAT
{
    public WAVEFORMATEX wfx;
    public ushort fwHeadLayer;
    public uint dwHeadBitrate;
    public ushort fwHeadMode;
    public ushort fwHeadModeExt;
    public ushort wHeadEmphasis;
    public ushort fwHeadFlags;
    public uint dwPTSLow;
    public uint dwPTSHigh;
}
Imports System.Runtime.InteropServices

<StructLayout(LayoutKind.Sequential, Pack:=1, CharSet:=CharSet.Unicode)>
Public Structure WAVEFORMATEX
    Public wFormatTag As UShort
    Public nChannels As UShort
    Public nSamplesPerSec As UInteger
    Public nAvgBytesPerSec As UInteger
    Public nBlockAlign As UShort
    Public wBitsPerSample As UShort
    Public cbSize As UShort
End Structure

<StructLayout(LayoutKind.Sequential, Pack:=1, CharSet:=CharSet.Unicode)>
Public Structure MPEG1WAVEFORMAT
    Public wfx As WAVEFORMATEX
    Public fwHeadLayer As UShort
    Public dwHeadBitrate As UInteger
    Public fwHeadMode As UShort
    Public fwHeadModeExt As UShort
    Public wHeadEmphasis As UShort
    Public fwHeadFlags As UShort
    Public dwPTSLow As UInteger
    Public dwPTSHigh As UInteger
End Structure
import ctypes
from ctypes import wintypes

class WAVEFORMATEX(ctypes.Structure):
    _pack_ = 1
    _fields_ = [
        ("wFormatTag", ctypes.c_ushort),
        ("nChannels", ctypes.c_ushort),
        ("nSamplesPerSec", wintypes.DWORD),
        ("nAvgBytesPerSec", wintypes.DWORD),
        ("nBlockAlign", ctypes.c_ushort),
        ("wBitsPerSample", ctypes.c_ushort),
        ("cbSize", ctypes.c_ushort),
    ]

class MPEG1WAVEFORMAT(ctypes.Structure):
    _pack_ = 1
    _fields_ = [
        ("wfx", WAVEFORMATEX),
        ("fwHeadLayer", ctypes.c_ushort),
        ("dwHeadBitrate", wintypes.DWORD),
        ("fwHeadMode", ctypes.c_ushort),
        ("fwHeadModeExt", ctypes.c_ushort),
        ("wHeadEmphasis", ctypes.c_ushort),
        ("fwHeadFlags", ctypes.c_ushort),
        ("dwPTSLow", wintypes.DWORD),
        ("dwPTSHigh", wintypes.DWORD),
    ]
#[repr(C, packed(1))]
pub struct WAVEFORMATEX {
    pub wFormatTag: u16,
    pub nChannels: u16,
    pub nSamplesPerSec: u32,
    pub nAvgBytesPerSec: u32,
    pub nBlockAlign: u16,
    pub wBitsPerSample: u16,
    pub cbSize: u16,
}

#[repr(C, packed(1))]
pub struct MPEG1WAVEFORMAT {
    pub wfx: WAVEFORMATEX,
    pub fwHeadLayer: u16,
    pub dwHeadBitrate: u32,
    pub fwHeadMode: u16,
    pub fwHeadModeExt: u16,
    pub wHeadEmphasis: u16,
    pub fwHeadFlags: u16,
    pub dwPTSLow: u32,
    pub dwPTSHigh: u32,
}
import "golang.org/x/sys/windows"

type WAVEFORMATEX struct {
	wFormatTag uint16
	nChannels uint16
	nSamplesPerSec uint32
	nAvgBytesPerSec uint32
	nBlockAlign uint16
	wBitsPerSample uint16
	cbSize uint16
}

type MPEG1WAVEFORMAT struct {
	wfx WAVEFORMATEX
	fwHeadLayer uint16
	dwHeadBitrate uint32
	fwHeadMode uint16
	fwHeadModeExt uint16
	wHeadEmphasis uint16
	fwHeadFlags uint16
	dwPTSLow uint32
	dwPTSHigh uint32
}
type
  WAVEFORMATEX = packed record
    wFormatTag: Word;
    nChannels: Word;
    nSamplesPerSec: DWORD;
    nAvgBytesPerSec: DWORD;
    nBlockAlign: Word;
    wBitsPerSample: Word;
    cbSize: Word;
  end;

  MPEG1WAVEFORMAT = packed record
    wfx: WAVEFORMATEX;
    fwHeadLayer: Word;
    dwHeadBitrate: DWORD;
    fwHeadMode: Word;
    fwHeadModeExt: Word;
    wHeadEmphasis: Word;
    fwHeadFlags: Word;
    dwPTSLow: DWORD;
    dwPTSHigh: DWORD;
  end;
const WAVEFORMATEX = extern struct {
    wFormatTag: u16,
    nChannels: u16,
    nSamplesPerSec: u32,
    nAvgBytesPerSec: u32,
    nBlockAlign: u16,
    wBitsPerSample: u16,
    cbSize: u16,
};

const MPEG1WAVEFORMAT = extern struct {
    wfx: WAVEFORMATEX,
    fwHeadLayer: u16,
    dwHeadBitrate: u32,
    fwHeadMode: u16,
    fwHeadModeExt: u16,
    wHeadEmphasis: u16,
    fwHeadFlags: u16,
    dwPTSLow: u32,
    dwPTSHigh: u32,
};
type
  WAVEFORMATEX {.packed.} = object
    wFormatTag: uint16
    nChannels: uint16
    nSamplesPerSec: uint32
    nAvgBytesPerSec: uint32
    nBlockAlign: uint16
    wBitsPerSample: uint16
    cbSize: uint16

  MPEG1WAVEFORMAT {.packed.} = object
    wfx: WAVEFORMATEX
    fwHeadLayer: uint16
    dwHeadBitrate: uint32
    fwHeadMode: uint16
    fwHeadModeExt: uint16
    wHeadEmphasis: uint16
    fwHeadFlags: uint16
    dwPTSLow: uint32
    dwPTSHigh: uint32
align(1)
struct WAVEFORMATEX
{
    ushort wFormatTag;
    ushort nChannels;
    uint nSamplesPerSec;
    uint nAvgBytesPerSec;
    ushort nBlockAlign;
    ushort wBitsPerSample;
    ushort cbSize;
}

align(1)
struct MPEG1WAVEFORMAT
{
    WAVEFORMATEX wfx;
    ushort fwHeadLayer;
    uint dwHeadBitrate;
    ushort fwHeadMode;
    ushort fwHeadModeExt;
    ushort wHeadEmphasis;
    ushort fwHeadFlags;
    uint dwPTSLow;
    uint dwPTSHigh;
}

HSP用 定義

HSP3.7/3.8 は構造体機能が無いため4byte整数配列(dim)+peek/poke で操作(32/64bitでサイズ・位置が異なる場合はタブで分割)。IronHSP は NSTRUCT(#defstruct/stdim/->)で32/64bit共通。

; HSP3.7/3.8 は構造体機能が無いため、4byte整数の配列変数で操作します。(x64 レイアウト)
; MPEG1WAVEFORMAT サイズ: 40 バイト(x64)
dim st, 10    ; 4byte整数×10(構造体サイズ 40 / 4 切り上げ)
; wfx : WAVEFORMATEX (+0, 18byte)  varptr(st)+0 を基点に操作(18byte:入れ子/配列)
; fwHeadLayer : WORD (+18, 2byte)  wpoke st,18,値  /  値 = wpeek(st,18)
; dwHeadBitrate : DWORD (+20, 4byte)  st.5 = 値  /  値 = st.5   (lpoke/lpeek も可)
; fwHeadMode : WORD (+24, 2byte)  wpoke st,24,値  /  値 = wpeek(st,24)
; fwHeadModeExt : WORD (+26, 2byte)  wpoke st,26,値  /  値 = wpeek(st,26)
; wHeadEmphasis : WORD (+28, 2byte)  wpoke st,28,値  /  値 = wpeek(st,28)
; fwHeadFlags : WORD (+30, 2byte)  wpoke st,30,値  /  値 = wpeek(st,30)
; dwPTSLow : DWORD (+32, 4byte)  st.8 = 値  /  値 = st.8   (lpoke/lpeek も可)
; dwPTSHigh : DWORD (+36, 4byte)  st.9 = 値  /  値 = st.9   (lpoke/lpeek も可)
; ※4byte境界の整数は添字 st.N(N=オフセット/4)で読み書き可。それ以外は peek/poke 系を使用。
; IronHSP は NSTRUCT(構造体)をサポート。32bit/64bit どちらでも同じコードで動作します。
; ※GUID・入れ子構造体はデフォルト型でないため、依存する #defstruct を先に定義(下記に同梱)。
#defstruct global WAVEFORMATEX, pack=1
    #field short wFormatTag
    #field short nChannels
    #field int nSamplesPerSec
    #field int nAvgBytesPerSec
    #field short nBlockAlign
    #field short wBitsPerSample
    #field short cbSize
#endstruct

#defstruct global MPEG1WAVEFORMAT, pack=1
    #field WAVEFORMATEX wfx
    #field short fwHeadLayer
    #field int dwHeadBitrate
    #field short fwHeadMode
    #field short fwHeadModeExt
    #field short wHeadEmphasis
    #field short fwHeadFlags
    #field int dwPTSLow
    #field int dwPTSHigh
#endstruct

stdim st, MPEG1WAVEFORMAT        ; NSTRUCT 変数を確保
st->fwHeadLayer = 100
mes "fwHeadLayer=" + st->fwHeadLayer