How to change .wav format file bit-rate

Question

Hi all,

In my application i ahve some .wav format audio files,so here i want to change Bit rate, for that i am using below code

<pre lang="C#">int bitrate;

using (var reader = new WaveFileReader(textBox1.Text))

{

bitrate = reader.WaveFormat.AverageBytesPerSecond * 8;

reader.Dispose();

}

if (bitrate &gt; 128000)

{

using (var reader = new WaveFileReader(textBox1.Text))

{

var newFormat = new WaveFormat(8000, 16, 1);

using (var conversionStream = new WaveFormatConversionStream(newFormat, reader))

{

WaveFileWriter.CreateWaveFile(@"C:\Docs\Files\", conversionStream);

}

}

}</pre>

it is working for some files only, and some files get below error

<pre lang="C#">An unhandled exception of type 'NAudio.MmException' occurred in NAudio.dll

Additional information: AcmNotPossible calling acmStreamOpen</pre>

How can i solve the error ?

--Here i am using Naudio Dll