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ShowWaveForm

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4.45/5 (14 votes)
21 Aug 2003 145K   5.3K   81   19
A C# class for working with .WAV files

Sample Image - showwaveform.jpg

Introduction

ShowWaveForm is based off of a c++ class written by Alexander Beletsky called CWaveFile. This is a port to C#, with some added features. A small .wav file is included in the demo project .zip file for testing.

WaveFile.cs

WaveFile.cs is the main class. It reads & parses the .WAV file headers. When passed a PaintEventArgs (typically from an OnPaint event), it will draw the waveform. The class also allows for zooming in/out on the waveform.

Usage

Using the class is very simple. Here is the sample project file open menu handler:

C#
private void fileOpen_Click(object sender, System.EventArgs e)
{
  OpenFileDialog fileDlg = new OpenFileDialog();

  if ( fileDlg.ShowDialog() == DialogResult.OK )
  {
     wave = new WaveFile( fileDlg.FileName );
     sbpMainPanel.Text = "Reading .WAV file...";
     wave.Read( );
     sbpMainPanel.Text = "Finished Reading .WAV file...";
     m_DrawWave = true;
     Refresh( );
  }
}

And here is the Paint handler of the demo project:

C#
private void Form1_Paint( object sender, 
              System.Windows.Forms.PaintEventArgs e
            )
{
  Pen pen = new Pen( ForeColor );
  if ( m_DrawWave )<BR>  {
     sbpMainPanel.Text = "Drawing .WAV file...";
     wave.Draw( e, pen );
     sbpMainPanel.Text = "Finished drawing .WAV file...";
  }
}

The last interesting thing in the demo project is the MouseWheel handler, which controls the zooming of the waveform:

C#
protected override void OnMouseWheel( MouseEventArgs mea )
{
 if ( mea.Delta * SystemInformation.MouseWheelScrollLines / 120 > 0 )
  wave.ZoomIn( );
 else
  wave.ZoomOut( );

 Refresh( );

}

Questions/Discussion

This is my first attempt at programming in C#/.NET. So please comment on every thing in this code! Specifically I have questions about:

  • Drawing of waveform is very slow for large files, perhaps because of using PageScale?
  • How to catch some of the errors that can occur in zooming in/out too far
  • Drawing of stereo waveforms

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


Written By
Web Developer
United States United States
PJ currently works for Avid Technology, and lives in Cambridge, MA. When he isn't coding, you can find him collecting old dusty funk & soul records.

Comments and Discussions

 
Questionstill works Pin
Christ Kennedy1-Nov-20 9:41
mvaChrist Kennedy1-Nov-20 9:41 
GeneralMy 5/5 ! ReadMe ! Pin
f_numb3r12-Jun-07 21:44
f_numb3r12-Jun-07 21:44 
GeneralShow waveform Result Vs Matlab Waveform Pin
gsrivastav7-May-07 0:41
gsrivastav7-May-07 0:41 
GeneralCreate Image Pin
jus_1011-May-05 16:58
jus_1011-May-05 16:58 
GeneralRe: Create Image Pin
Christian Graus1-May-05 17:12
protectorChristian Graus1-May-05 17:12 
GeneralRe: Create Image Pin
jus_1011-May-05 17:14
jus_1011-May-05 17:14 
GeneralRe: Create Image Pin
Christian Graus1-May-05 17:17
protectorChristian Graus1-May-05 17:17 
GeneralRe: Create Image Pin
jus_1013-May-05 13:14
jus_1013-May-05 13:14 
GeneralRe: Create Image Pin
Christian Graus3-May-05 13:21
protectorChristian Graus3-May-05 13:21 
GeneralRe: Create Image Pin
jus_1013-May-05 13:47
jus_1013-May-05 13:47 
GeneralRe: Create Image Pin
Member 41617801-May-08 12:16
Member 41617801-May-08 12:16 
Hi
I converted and ran the code in VS2005. The runs without an error, however the line and graph is not visible in the main window. I opened "Shortwav.wav", the message at the bottom left shows that the "finished drawing .WAV file", however no image is drawn on the canvas.

Any help would be useful

Cheers,
Vimal
QuestionDataID invalid?? Pin
cbranje11-Sep-04 1:55
cbranje11-Sep-04 1:55 
AnswerRe: DataID invalid?? Pin
mauricerulez8-Nov-06 1:51
mauricerulez8-Nov-06 1:51 
GeneralRe: DataID invalid?? Pin
sandu20041-Jul-07 23:34
sandu20041-Jul-07 23:34 
GeneralZoom Problem Pin
jk chan20-Jun-04 20:15
jk chan20-Jun-04 20:15 
QuestionLink/Explanation? Pin
Jeremy Kimball26-Aug-03 19:41
Jeremy Kimball26-Aug-03 19:41 
AnswerRe: Link/Explanation? Pin
pj453327-Aug-03 7:26
pj453327-Aug-03 7:26 
GeneralRe: Link/Explanation? Pin
zgraf11-Dec-05 14:42
zgraf11-Dec-05 14:42 
QuestionRe: DOUBT Pin
FlavioAR16-Aug-07 14:14
FlavioAR16-Aug-07 14:14 

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