vb.net读取声卡 提取声卡codec

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vb.net读取声卡，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vb.net读取声卡：

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。

首先把媒体播放器控件加到工具栏中，调用还是简单的写一下吧：）

Private Sub playMediaFile(ByVal mediaFileName As String)

With MediaPlayer1

.Stop()

.FileName = "c:\mp3\爱不爱我.mp3"

.Play()

End With

End Sub

vb.net中如何播放声音，是要什么控件嘛？

My.Computer.Audio.Play("SoundFile.wav")

SoundFile.wav是你要播放的声音文件的路径

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

vb.net读取声卡的介绍就聊到这里吧，感谢你花时间阅读本站内容，更多关于提取声卡codec、vb.net读取声卡的信息别忘了在本站进行查找喔。