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WaveformAnalyzer.PeaksBufferGet method |
  
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WaveformAnalyzer.PeaksBufferGet method |
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Remarks
Fills two buffers with min and max waveform peaks for the given range. The size of each buffer can be obtained with a previous call to the WaveformAnalyzer.PeaksBufferLengthGet method.
Before calling this method it's mandatory performing a previous sound's analysis through a call to the WaveformAnalyzer.AnalyzeFullSound method and waiting its completion through the WaveAnalysisDone event.
For details about the use of the Waveform Analyzer refer to the How to use the Waveform Analyzer section.
For further details about methods of the Waveform Analyzer refer to the WaveformAnalyzer class section.
Syntax
[Visual Basic] Public Function PeaksBufferGet ( nChannel as Int16, nStartPos as Int32, nEndPos as Int32, bValueInPerc as Boolean, pBufferMin() as Int16, pBufferMax() as Int16, nBufferLength as Int32 ) as enumErrorCodes |
[C#] public enumErrorCodes PeaksBufferGet ( Int16 nChannel, Int32 nStartPos, Int32 nEndPos, bool bValueInPerc, Int16[] pBufferMin, Int16[] pBufferMax, Int32 nBufferLength ); |
[C++] public: enumErrorCodes PeaksBufferGet ( Int16 nChannel, Int32 nStartPos, Int32 nEndPos, bool bValueInPerc, Int16 __gc[] pBufferMin, Int16 __gc[] pBufferMax, Int32 nBufferLength ); |
Parameter |
Description |
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nChannel |
Number representing the audio channel we are interested in. Can be a value between 0 and 7. |
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nStartPos |
Number representing the start position, expressed in milliseconds, where we want to get waveform's peaks. The value 0 represents the sound's beginning. |
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nEndPos |
Number representing the end position, expressed in milliseconds, where we want to get waveform's peaks. The value -1 represents the sound's end. |
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bValueInPerc |
Boolean value that specifies if the given buffers should be filled with values expressed in percentage. Supported values are the following:
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pBufferMin |
Variant parameter containing the pointer to the buffer that, on return from the method call, will contain the min waveform peaks. |
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pBufferMax |
Variant parameter containing the pointer to the buffer that, on return from the method call, will contain the max waveform peaks. |
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nBufferLength |
Length in bytes of the given buffers previously obtained through the Waveform.PeaksBufferLengthGet method. |
Return value
Value |
Meaning |
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Negative value |
An error occurred (see the LastError property for further error details) |
enumErrorCodes.NOERROR (0) |
The method call was successful. |
Samples
Below you can find a couple of samples that demonstrate how to load waveform peaks in Visual Basic.NET and Visual C#
Visual Basic.NET
' memory buffers must be declared as global variables
Dim m_bufferMin() As Int16
Dim m_bufferMax() As Int16
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
' get the size in bytes of the buffers
Dim nBufferLength As Int32 = 0
AudioSoundRecorder1.DisplayWaveformAnalyzer.PeaksBufferLengthGet (nStartPosInMs, nEndPosInMs, nBufferLength)
' reallocate the memory buffer space and store the song
ReDim m_bufferMin(nBufferLength/2)
ReDim m_bufferMax(nBufferLength/2)
' fill the buffers with peaks data
AudioSoundRecorder1.DisplayWaveformAnalyzer.PeaksBufferGet (0, nStartPosInMs, nEndPosInMs, true, m_bufferMin, m_bufferMax, nBufferLength)
End Sub
Visual C#.NET
// declare the memory buffer (cannot be a local variable)
Int16[] m_bufferMin = null;
Int16[] m_bufferMax = null;
private void buttonLoad1_Click(object sender, System.EventArgs e)
{
// get the size in bytes of the buffers
Int32 nBufferLength = 0;
AudioSoundRecorder1.DisplayWaveformAnalyzer.PeaksBufferLengthGet (nStartPosInMs, nEndPosInMs, ref nBufferLength);
// reallocate the memory buffer space and store the song
m_bufferMin = new Int16[nBufferLength/2];
m_bufferMax = new Int16[nBufferLength/2];
// fill the buffers with peaks data
AudioSoundRecorder1.DisplayWaveformAnalyzer.PeaksBufferGet (0, nStartPosInMs, nEndPosInMs, true, m_bufferMin, m_bufferMax, nBufferLength);
}
