WaveFormatEx 结构的托管使用

typedefstruct {

WORD wFormatTag;

WORD nChannels;

 DWORD nSamplesPerSec;

 DWORD nAvgBytesPerSec;

WORD nBlockAlign;

WORD wBitsPerSample;

WORD cbSize;

}WAVEFORMATEX;

 

以上为WaveFormatEx的C语言定义

 

在C#中可以写成：

 

    [StructLayout(LayoutKind.Sequential)]

publicclassWaveFormatEx

    {

privateshortwFormatTag;

privateshortnChannels;

privateintnSamplesPerSec;

privateintnAvgBytesPerSec;

privateshortnBlockAlign;

privateshortwBitsPerSample;

    }

 

由于在PInvoke时传递的都是该结构的指针，所以为了方便编码这里就把它定义成类（若定义成struct的话则要做一些取地址再传指针的麻烦操作）。

这里也可以看出，class被称为引用类型，在作为参数传递时它就是以指针传递的

且由于要与非托管代码交互，所以要用固定内存布局[StructLayout(LayoutKind.Sequential)]来标记它。

 

WORD - typedef unsigned short WORD; 16位无符号整数

DWORD - typedef unsigned long DWORD; 32位无符号整数

既然都是无符号的，WORD就应写成UInt16(ushort).DWORD就应写成UInt32(uint).

那这里为何要用short 及int？

我的个人建议：在平台交换时，应尽量使用CLS兼容的数据类型。并且，只要位宽一样，数据的表示总是对的，因为PINVOKE会自动调用转换，且转换的开销很小乃至无开销（熟悉计算机基础架构的人很容易理解无开销的意思，具体有没有转换要看.net是怎么设计的，我不了解）。

 

 

wFormatTag是格式标签，几乎都是已定义好的一些常数

如pcm格式是0

Adpcm是1

杜比Ac2 是30

有好多。过后我会给出

其中最常用的就是PCM 和ADPCM

 

nChannels是声道数

nSamplesPerSec是 Samples per second ，即每秒的样本数量，也就是传说中的速率、采样率。每秒有多少个样本的确可以反应“率”的概念

nAvgBytesPerSec平均传输速率。如果是PCM的话，则该值等于nSamplesPerSec除以nBlockAlign。

nBlockAlign        数据块调整度(块对其,字节)，其值为通道数*样本的数据位值/8，播放软件需要与一次处理多个该值大小的字节数据，以将其中于缓冲区调整

wBitsPerSample           每个样本的位数。表示每个声道中各个样本的数据位数。如果有多个声道，对每个声道而言样本大小都一样

cbSize        该结构（类）的大小 

 

 常见的Format Tag:

public enum WaveFormatTag : ushort { /// <summary>WAVE_FORMAT_UNKNOWN, Microsoft Corporation</summary> Unknown = 0x0000, /// <summary>WAVE_FORMAT_PCM Microsoft Corporation</summary> Pcm = 0x0001, /// <summary>WAVE_FORMAT_ADPCM Microsoft Corporation</summary> Adpcm = 0x0002, /// <summary>WAVE_FORMAT_IEEE_FLOAT Microsoft Corporation</summary> IeeeFloat = 0x0003, /// <summary>WAVE_FORMAT_VSELP Compaq Computer Corp.</summary> Vselp = 0x0004, /// <summary>WAVE_FORMAT_IBM_CVSD IBM Corporation</summary> IbmCvsd = 0x0005, /// <summary>WAVE_FORMAT_ALAW Microsoft Corporation</summary> ALaw = 0x0006, /// <summary>WAVE_FORMAT_MULAW Microsoft Corporation</summary> MuLaw = 0x0007, /// <summary>WAVE_FORMAT_DTS Microsoft Corporation</summary> Dts = 0x0008, /// <summary>WAVE_FORMAT_DRM Microsoft Corporation</summary> Drm = 0x0009, /// <summary>WAVE_FORMAT_OKI_ADPCM OKI</summary> OkiAdpcm = 0x0010, /// <summary>WAVE_FORMAT_DVI_ADPCM Intel Corporation</summary> DviAdpcm = 0x0011, /// <summary>WAVE_FORMAT_IMA_ADPCM Intel Corporation</summary> ImaAdpcm = DviAdpcm, /// <summary>WAVE_FORMAT_MEDIASPACE_ADPCM Videologic</summary> MediaspaceAdpcm = 0x0012, /// <summary>WAVE_FORMAT_SIERRA_ADPCM Sierra Semiconductor Corp </summary> SierraAdpcm = 0x0013, /// <summary>WAVE_FORMAT_G723_ADPCM Antex Electronics Corporation </summary> G723Adpcm = 0x0014, /// <summary>WAVE_FORMAT_DIGISTD DSP Solutions, Inc.</summary> DigiStd = 0x0015, /// <summary>WAVE_FORMAT_DIGIFIX DSP Solutions, Inc.</summary> DigiFix = 0x0016, /// <summary>WAVE_FORMAT_DIALOGIC_OKI_ADPCM Dialogic Corporation</summary> DialogicOkiAdpcm = 0x0017, /// <summary>WAVE_FORMAT_MEDIAVISION_ADPCM Media Vision, Inc.</summary> MediaVisionAdpcm = 0x0018, /// <summary>WAVE_FORMAT_CU_CODEC Hewlett-Packard Company </summary> CUCodec = 0x0019, /// <summary>WAVE_FORMAT_YAMAHA_ADPCM Yamaha Corporation of America</summary> YamahaAdpcm = 0x0020, /// <summary>WAVE_FORMAT_SONARC Speech Compression</summary> SonarC = 0x0021, /// <summary>WAVE_FORMAT_DSPGROUP_TRUESPEECH DSP Group, Inc </summary> DspGroupTruespeech = 0x0022, /// <summary>WAVE_FORMAT_ECHOSC1 Echo Speech Corporation</summary> EchoSpeechCorporation1 = 0x0023, /// <summary>WAVE_FORMAT_AUDIOFILE_AF36, Virtual Music, Inc.</summary> AudioFileAf36 = 0x0024, /// <summary>WAVE_FORMAT_APTX Audio Processing Technology</summary> Aptx = 0x0025, /// <summary>WAVE_FORMAT_AUDIOFILE_AF10, Virtual Music, Inc.</summary> AudioFileAf10 = 0x0026, /// <summary>WAVE_FORMAT_PROSODY_1612, Aculab plc</summary> Prosody1612 = 0x0027, /// <summary>WAVE_FORMAT_LRC, Merging Technologies S.A. </summary> Lrc = 0x0028, /// <summary>WAVE_FORMAT_DOLBY_AC2, Dolby Laboratories</summary> DolbyAc2 = 0x0030, /// <summary>WAVE_FORMAT_GSM610, Microsoft Corporation</summary> Gsm610 = 0x0031, /// <summary>WAVE_FORMAT_MSNAUDIO, Microsoft Corporation</summary> MsnAudio = 0x0032, /// <summary>WAVE_FORMAT_ANTEX_ADPCME, Antex Electronics Corporation</summary> AntexAdpcme = 0x0033, /// <summary>WAVE_FORMAT_CONTROL_RES_VQLPC, Control Resources Limited </summary> ControlResVqlpc = 0x0034, /// <summary>WAVE_FORMAT_DIGIREAL, DSP Solutions, Inc. </summary> DigiReal = 0x0035, /// <summary>WAVE_FORMAT_DIGIADPCM, DSP Solutions, Inc.</summary> DigiAdpcm = 0x0036, /// <summary>WAVE_FORMAT_CONTROL_RES_CR10, Control Resources Limited</summary> ControlResCr10 = 0x0037, /// <summary></summary> WAVE_FORMAT_NMS_VBXADPCM = 0x0038, // Natural MicroSystems /// <summary></summary> WAVE_FORMAT_CS_IMAADPCM = 0x0039, // Crystal Semiconductor IMA ADPCM /// <summary></summary> WAVE_FORMAT_ECHOSC3 = 0x003A, // Echo Speech Corporation /// <summary></summary> WAVE_FORMAT_ROCKWELL_ADPCM = 0x003B, // Rockwell International /// <summary></summary> WAVE_FORMAT_ROCKWELL_DIGITALK = 0x003C, // Rockwell International /// <summary></summary> WAVE_FORMAT_XEBEC = 0x003D, // Xebec Multimedia Solutions Limited /// <summary></summary> WAVE_FORMAT_G721_ADPCM = 0x0040, // Antex Electronics Corporation /// <summary></summary> WAVE_FORMAT_G728_CELP = 0x0041, // Antex Electronics Corporation /// <summary></summary> WAVE_FORMAT_MSG723 = 0x0042, // Microsoft Corporation /// <summary></summary> Mpeg = 0x0050, // WAVE_FORMAT_MPEG, Microsoft Corporation /// <summary></summary> WAVE_FORMAT_RT24 = 0x0052, // InSoft, Inc. /// <summary></summary> WAVE_FORMAT_PAC = 0x0053, // InSoft, Inc. /// <summary></summary> MpegLayer3 = 0x0055, // WAVE_FORMAT_MPEGLAYER3, ISO/MPEG Layer3 Format Tag /// <summary></summary> WAVE_FORMAT_LUCENT_G723 = 0x0059, // Lucent Technologies /// <summary></summary> WAVE_FORMAT_CIRRUS = 0x0060, // Cirrus Logic /// <summary></summary> WAVE_FORMAT_ESPCM = 0x0061, // ESS Technology /// <summary></summary> WAVE_FORMAT_VOXWARE = 0x0062, // Voxware Inc /// <summary></summary> WAVE_FORMAT_CANOPUS_ATRAC = 0x0063, // Canopus, co., Ltd. /// <summary></summary> WAVE_FORMAT_G726_ADPCM = 0x0064, // APICOM /// <summary></summary> WAVE_FORMAT_G722_ADPCM = 0x0065, // APICOM /// <summary></summary> WAVE_FORMAT_DSAT_DISPLAY = 0x0067, // Microsoft Corporation /// <summary></summary> WAVE_FORMAT_VOXWARE_BYTE_ALIGNED = 0x0069, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_AC8 = 0x0070, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_AC10 = 0x0071, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_AC16 = 0x0072, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_AC20 = 0x0073, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_RT24 = 0x0074, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_RT29 = 0x0075, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_RT29HW = 0x0076, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_VR12 = 0x0077, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_VR18 = 0x0078, // Voxware Inc /// <summary></summary> WAVE_FORMAT_VOXWARE_TQ40 = 0x0079, // Voxware Inc /// <summary></summary> WAVE_FORMAT_SOFTSOUND = 0x0080, // Softsound, Ltd. /// <summary></summary> WAVE_FORMAT_VOXWARE_TQ60 = 0x0081, // Voxware Inc /// <summary></summary> WAVE_FORMAT_MSRT24 = 0x0082, // Microsoft Corporation /// <summary></summary> WAVE_FORMAT_G729A = 0x0083, // AT&T Labs, Inc. /// <summary></summary> WAVE_FORMAT_MVI_MVI2 = 0x0084, // Motion Pixels /// <summary></summary> WAVE_FORMAT_DF_G726 = 0x0085, // DataFusion Systems (Pty) (Ltd) /// <summary></summary> WAVE_FORMAT_DF_GSM610 = 0x0086, // DataFusion Systems (Pty) (Ltd) /// <summary></summary> WAVE_FORMAT_ISIAUDIO = 0x0088, // Iterated Systems, Inc. /// <summary></summary> WAVE_FORMAT_ONLIVE = 0x0089, // OnLive! Technologies, Inc. /// <summary></summary> WAVE_FORMAT_SBC24 = 0x0091, // Siemens Business Communications Sys /// <summary></summary> WAVE_FORMAT_DOLBY_AC3_SPDIF = 0x0092, // Sonic Foundry /// <summary></summary> WAVE_FORMAT_MEDIASONIC_G723 = 0x0093, // MediaSonic /// <summary></summary> WAVE_FORMAT_PROSODY_8KBPS = 0x0094, // Aculab plc /// <summary></summary> WAVE_FORMAT_ZYXEL_ADPCM = 0x0097, // ZyXEL Communications, Inc. /// <summary></summary> WAVE_FORMAT_PHILIPS_LPCBB = 0x0098, // Philips Speech Processing /// <summary></summary> WAVE_FORMAT_PACKED = 0x0099, // Studer Professional Audio AG /// <summary></summary> WAVE_FORMAT_MALDEN_PHONYTALK = 0x00A0, // Malden Electronics Ltd. /// <summary>WAVE_FORMAT_GSM</summary> Gsm = 0x00A1, /// <summary>WAVE_FORMAT_G729</summary> G729 = 0x00A2, /// <summary>WAVE_FORMAT_G723</summary> G723 = 0x00A3, /// <summary>WAVE_FORMAT_ACELP</summary> Acelp = 0x00A4, /// <summary></summary> WAVE_FORMAT_RHETOREX_ADPCM = 0x0100, // Rhetorex Inc. /// <summary></summary> WAVE_FORMAT_IRAT = 0x0101, // BeCubed Software Inc. /// <summary></summary> WAVE_FORMAT_VIVO_G723 = 0x0111, // Vivo Software /// <summary></summary> WAVE_FORMAT_VIVO_SIREN = 0x0112, // Vivo Software /// <summary></summary> WAVE_FORMAT_DIGITAL_G723 = 0x0123, // Digital Equipment Corporation /// <summary></summary> WAVE_FORMAT_SANYO_LD_ADPCM = 0x0125, // Sanyo Electric Co., Ltd. /// <summary></summary> WAVE_FORMAT_SIPROLAB_ACEPLNET = 0x0130, // Sipro Lab Telecom Inc. /// <summary></summary> WAVE_FORMAT_SIPROLAB_ACELP4800 = 0x0131, // Sipro Lab Telecom Inc. /// <summary></summary> WAVE_FORMAT_SIPROLAB_ACELP8V3 = 0x0132, // Sipro Lab Telecom Inc. /// <summary></summary> WAVE_FORMAT_SIPROLAB_G729 = 0x0133, // Sipro Lab Telecom Inc. /// <summary></summary> WAVE_FORMAT_SIPROLAB_G729A = 0x0134, // Sipro Lab Telecom Inc. /// <summary></summary> WAVE_FORMAT_SIPROLAB_KELVIN = 0x0135, // Sipro Lab Telecom Inc. /// <summary></summary> WAVE_FORMAT_G726ADPCM = 0x0140, // Dictaphone Corporation /// <summary></summary> WAVE_FORMAT_QUALCOMM_PUREVOICE = 0x0150, // Qualcomm, Inc. /// <summary></summary> WAVE_FORMAT_QUALCOMM_HALFRATE = 0x0151, // Qualcomm, Inc. /// <summary></summary> WAVE_FORMAT_TUBGSM = 0x0155, // Ring Zero Systems, Inc. /// <summary></summary> WAVE_FORMAT_MSAUDIO1 = 0x0160, // Microsoft Corporation /// <summary> /// WAVE_FORMAT_WMAUDIO2, Microsoft Corporation /// </summary> WAVE_FORMAT_WMAUDIO2 = 0x0161, /// <summary> /// WAVE_FORMAT_WMAUDIO3, Microsoft Corporation /// </summary> WAVE_FORMAT_WMAUDIO3 = 0x0162, /// <summary></summary> WAVE_FORMAT_UNISYS_NAP_ADPCM = 0x0170, // Unisys Corp. /// <summary></summary> WAVE_FORMAT_UNISYS_NAP_ULAW = 0x0171, // Unisys Corp. /// <summary></summary> WAVE_FORMAT_UNISYS_NAP_ALAW = 0x0172, // Unisys Corp. /// <summary></summary> WAVE_FORMAT_UNISYS_NAP_16K = 0x0173, // Unisys Corp. /// <summary></summary> WAVE_FORMAT_CREATIVE_ADPCM = 0x0200, // Creative Labs, Inc /// <summary></summary> WAVE_FORMAT_CREATIVE_FASTSPEECH8 = 0x0202, // Creative Labs, Inc /// <summary></summary> WAVE_FORMAT_CREATIVE_FASTSPEECH10 = 0x0203, // Creative Labs, Inc /// <summary></summary> WAVE_FORMAT_UHER_ADPCM = 0x0210, // UHER informatic GmbH /// <summary></summary> WAVE_FORMAT_QUARTERDECK = 0x0220, // Quarterdeck Corporation /// <summary></summary> WAVE_FORMAT_ILINK_VC = 0x0230, // I-link Worldwide /// <summary></summary> WAVE_FORMAT_RAW_SPORT = 0x0240, // Aureal Semiconductor /// <summary></summary> WAVE_FORMAT_ESST_AC3 = 0x0241, // ESS Technology, Inc. /// <summary></summary> WAVE_FORMAT_IPI_HSX = 0x0250, // Interactive Products, Inc. /// <summary></summary> WAVE_FORMAT_IPI_RPELP = 0x0251, // Interactive Products, Inc. /// <summary></summary> WAVE_FORMAT_CS2 = 0x0260, // Consistent Software /// <summary></summary> WAVE_FORMAT_SONY_SCX = 0x0270, // Sony Corp. /// <summary></summary> WAVE_FORMAT_FM_TOWNS_SND = 0x0300, // Fujitsu Corp. /// <summary></summary> WAVE_FORMAT_BTV_DIGITAL = 0x0400, // Brooktree Corporation /// <summary></summary> WAVE_FORMAT_QDESIGN_MUSIC = 0x0450, // QDesign Corporation /// <summary></summary> WAVE_FORMAT_VME_VMPCM = 0x0680, // AT&T Labs, Inc. /// <summary></summary> WAVE_FORMAT_TPC = 0x0681, // AT&T Labs, Inc. /// <summary></summary> WAVE_FORMAT_OLIGSM = 0x1000, // Ing C. Olivetti & C., S.p.A. /// <summary></summary> WAVE_FORMAT_OLIADPCM = 0x1001, // Ing C. Olivetti & C., S.p.A. /// <summary></summary> WAVE_FORMAT_OLICELP = 0x1002, // Ing C. Olivetti & C., S.p.A. /// <summary></summary> WAVE_FORMAT_OLISBC = 0x1003, // Ing C. Olivetti & C., S.p.A. /// <summary></summary> WAVE_FORMAT_OLIOPR = 0x1004, // Ing C. Olivetti & C., S.p.A. /// <summary></summary> WAVE_FORMAT_LH_CODEC = 0x1100, // Lernout & Hauspie /// <summary></summary> WAVE_FORMAT_NORRIS = 0x1400, // Norris Communications, Inc. /// <summary></summary> WAVE_FORMAT_SOUNDSPACE_MUSICOMPRESS = 0x1500, // AT&T Labs, Inc. /// <summary></summary> WAVE_FORMAT_DVM = 0x2000, // FAST Multimedia AG /// <summary>WAVE_FORMAT_EXTENSIBLE</summary> Extensible = 0xFFFE, // Microsoft /// <summary></summary> WAVE_FORMAT_DEVELOPMENT = 0xFFFF, // others - not from MS headers /// <summary>WAVE_FORMAT_VORBIS1 "Og" Original stream compatible</summary> Vorbis1 = 0x674f, /// <summary>WAVE_FORMAT_VORBIS2 "Pg" Have independent header</summary> Vorbis2 = 0x6750, /// <summary>WAVE_FORMAT_VORBIS3 "Qg" Have no codebook header</summary> Vorbis3 = 0x6751, /// <summary>WAVE_FORMAT_VORBIS1P "og" Original stream compatible</summary> Vorbis1P = 0x676f, /// <summary>WAVE_FORMAT_VORBIS2P "pg" Have independent headere</summary> Vorbis2P = 0x6770, /// <summary>WAVE_FORMAT_VORBIS3P "qg" Have no codebook header</summary> Vorbis3P = 0x6771, WindowsMediaAudio = 0x161, WindowsMediaAudio9Professional = 0x162, WindowsMediaAudio9Lossless = 0x163, //09.12.5做了改动 }

 WaveFormatEx 完整定义:

[StructLayout(LayoutKind.Sequential)] public class WaveFormatEx { private short wFormatTag; public short FormatTag { get { return wFormatTag; } set { wFormatTag = value; } } private short nChannels; public short Channels { get { return nChannels; } set { nChannels = value; } } private int nSamplesPerSec; public int SamplesPerSec { get { return nSamplesPerSec; } set { nSamplesPerSec = value; } } private int nAvgBytesPerSec; public int AvgBytesPerSec { get { return nAvgBytesPerSec; } set { nAvgBytesPerSec = value; } } private short nBlockAlign; public short BlockAlign { get { return nBlockAlign; } set { nBlockAlign = value; } } private short wBitsPerSample; public short BitsPerSample { get { return wBitsPerSample; } set { wBitsPerSample = value; } } private short cbSize; public short Size { get { return cbSize; } set { cbSize = value; } } public WaveFormatEx() { } /// <summary> /// 默认构造 /// </summary> /// <temp_param name="samplesPerSec" ></temp_param><param name="samplesPerSec" ></param> /// <temp_param name="bitsPerSample" ></temp_param><param name="bitsPerSample" ></param> /// <temp_param name="channels" ></temp_param><param name="channels" ></param> public WaveFormatEx(int samplesPerSec/*rate*/, int bitsPerSample, int channels) { wFormatTag = (short)WaveFormatTag.Pcm; nChannels = (short)channels; nSamplesPerSec = samplesPerSec; wBitsPerSample = (short)bitsPerSample; cbSize = 0; nBlockAlign = (short)(channels * (bitsPerSample / 8)); nAvgBytesPerSec = nSamplesPerSec * nBlockAlign; } /// <summary> /// 已重载 /// </summary> /// <returns></returns> public override string ToString() { return string.Format("FormatTag : {0}\nChannels : {1}\nSamplesPerSec : {2}\nAvgBytesPerSec : {3}\nBlockAlign : {4}\nBitsPerSample : {5}\ncbSize : {6}" , wFormatTag , nChannels , nSamplesPerSec , nAvgBytesPerSec , nBlockAlign , wBitsPerSample , cbSize); } /// <summary> /// 由延迟转的字节量 /// </summary> /// <temp_param name="milliseconds" ></temp_param><param name="milliseconds" ></param> /// <returns></returns> public int ConvertLatencyToByteSize(int milliseconds) { int num = (int)((((double)this.AvgBytesPerSec) / 1000.0) * milliseconds); if ((num % this.BlockAlign) != 0) { num = (num + this.BlockAlign) - (num % this.BlockAlign); } return num; } public WaveFormatEx Clone() { return new WaveFormatEx(nSamplesPerSec, wBitsPerSample, nChannels); } }