vb.net读取声卡数据 labview基于声卡的声音识别

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vb如何读取声卡信号

vb读取声卡信号调用C：\WINDOWS\system32\sndrec32.exe程序。根据查询相关公开信息显示，vb读取声卡信号调用C：\WINDOWS\system32\sndrec32.exe程序（录音机），将音频信号存储为*.wav文件即可。

相关问答

Q1: 我用二进制读取了声音文件，VB或VB.net如何播放二进制声音数据，请高手赐教！

不明白你为什么要二进制读取声音文件vb.net读取声卡数据，VB可以直接调用API播放声音文件，不需要你二进制来读取声音文件的。

Private

Declare Function sndPlaySound Lib "winmm.dll" Alias "sndPlaySoundA"

(ByVal lpszSoundName As String, ByVal uFlags As Long) As Long

Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Sub PlayWavFile(strFileName As String, PlayCount As Long, JianGe As Long)

'strFileName 要播放的文件名(带路径)

'playCount 播放的次数

'JianGe 多次播放时,每次的时间间隔

If Len(Dir(strFileName)) = 0 Then Exit Sub

If PlayCount = 0 Then Exit Sub

If JianGe 1000 Then JianGe = 1000

DoEvents

sndPlaySound strFileName, 16 + 1

Sleep JianGe

Call PlayWavFile(strFileName, PlayCount - 1, JianGe)

End Sub

Private Sub Form_Click()

PlayWavFile "C:\aaa.wav", 1, 1000 '参数vb.net读取声卡数据：播放文件，播放次数，播放间隔

End Sub

Q2: VB.net窗体设计中，如何读取.txt文件中的数据？

1、新建一个标准vb.net读取声卡数据的VB EXE工程vb.net读取声卡数据，只有一个Formvb.net读取声卡数据，Form上有两个按钮：Command1和Command2。

2、双击Command1添加如下代码

Private Sub Command1_Click()

Dim strFile As String

Dim intFile As Integer

Dim strData As String

strFile = "c:\学生成绩.txt"

intFile = FreeFile

Open strFile For Input As intFile

strData = StrConv(InputB(FileLen(strFile), intFile), vbUnicode)

Debug.Print strData

Close intFile

End Sub

3、按F8开始单步调试代码，点击Command1，进入单步调试功能，

4、多次按下F8或直接按下F5运行完成，就完成vb.net读取声卡数据了读取文本文件内容并输出到立即窗口。

Q3: vb.net的一个问题

蜂鸣器编程的话，有个API函数，VB中的声明为

Declare Function Beep Lib "kernel32" Alias "Beep" (ByVal dwFreq As Long, ByVal dwDuration As Long) As Long

调用方法是Beep 声音频率,持续时间（毫秒为单位）

比如 beep 2000,1000

如果是声卡编程的话，也有相应的API函数，比如你可以用DirectSound(也就是DirectX的一部分)，功能比较强大，也很专业。事实上，如果你使用的是专业级的声卡和音响设备，它可以在一定范围内回放出超出人耳听觉范围的声音。当然也可以用简单一点的API，以下是几个需要的函数：

Private Declare Function midiOutGetDevCaps Lib "winmm.dll" Alias "midiOutGetDevCapsA" (ByVal uDeviceID As Long, lpCaps As MIDIOUTCAPS, ByVal uSize As Long) As Long

Private Declare Function midiOutGetNumDevs Lib "winmm" () As Integer

Private Declare Function MIDIOutOpen Lib "winmm.dll" Alias "midiOutOpen" (lphMidiOut As Long, ByVal uDeviceID As Long, ByVal dwCallback As Long, ByVal dwInstance As Long, ByVal dwFlags As Long) As Long

Private Declare Function midiOutClose Lib "winmm.dll" (ByVal hMidiOut As Long) As Long

Private Declare Function midiOutShortMsg Lib "winmm.dll" (ByVal hMidiOut As Long, ByVal dwMsg As Long) As Long

Private Declare Function midiOutGetErrorText Lib "winmm.dll" Alias "midiOutGetErrorTextA" (ByVal err As Long, ByVal lpText As String, ByVal uSize As Long) As Long

Private Const MAXERRORLENGTH = 128 ' max error text length (including NULL)

Private Const MIDIMAPPER = (-1)

Private Const MIDI_MAPPER = (-1)

'MIDIOUTCAPS结构描述了Musical Instrument Digital Interface(MIDI)输入设备的性能

Type MIDIOUTCAPS

wMid As Integer

wPid As Integer ' 产品 ID

vDriverVersion As Long ' 设备版本

szPname As String * 32 ' 设备 name

wTechnology As Integer ' 设备类型

wVoices As Integer

wNotes As Integer

wChannelMask As Integer

dwSupport As Long

End Type

Public Sub note_on(ch As Integer, ByVal kk As Integer, v As Integer)

' 发音主函数。参数分别为通道编号，音调，速度

Call midi_outshort(H90 + ch, kk, v)

End Sub

Sub midi_outshort(b1 As Integer, b2 As Integer, b3 As Integer)

Dim midi_error As Integer

midi_error = midiOutShortMsg(hMidi, b3 * H10000 + b2 * H100 + b1)

If Not midi_error = 0 Then

Call midi_outerr(midi_error)

End If

End Sub

Sub midi_outerr(ByVal midi_error As Integer)

Dim s As String

Dim x As Integer

s = Space(MAXERRORLENGTH)

x = midiOutGetErrorText(midi_error, s, MAXERRORLENGTH)

MsgBox s

End Sub

Q4: vb.net怎么编程实现从音频输出口输出指定频率指定时长和占空比的单音信号。

1.用Win32 API PlaySound

PlaySound位于"winmm.dll"中，可以根据输入参数的不同，播放WAV类型的音乐。在VB.NET中调用跟VB6中差不多：

先声明：

Private Declare Auto Function PlaySound Lib "winmm.dll" (ByVal lpszSoundName As String, ByVal hModule As Integer, ByVal dwFlags As Integer) As Integer

Const SND_FILENAME As Integer = H20000

Const SND_ALIAS As Integer = H10000

Const SND_SYNC As Integer = H0

具体还有很多常量，不一一列举，下面是播放一个wav文件的例子

Dim mstrfileName As String = "c:\eagle2.wav"

PlaySound(mstrfileName, 0, SND_FILENAME)

注意上面的播放是非同步的，就是说它并不会播放完毕才结束。如果把上面的代码写在一个Button.Click的事件处理程序中，第二次点击的时候它会打断第一次的播放，重新开始。

当然我们也可以调用系统的声音：

PlaySound("SystemStart", 0, SND_ALIAS Or SND_SYNC)

' 以同步的方式调用系统启动时候的声音。

2．调用媒体播放器控件

VB.NET中并没有提供媒体播放器的.NET组件，没办法我们还是调用以前Com组件Windows Media Player。当然除了声音外，还可以播放视频文件。