ASP NET MVC and HTML5 audio - file not playing - asp.net-mvc

Question

I am trying to create a table containing audio files, which should start playing when the user clicks the play button. This is what I've tried so far:
Controller:
[HttpGet]
public ActionResult PlayFile(string FilePath)
{
WebClient WC = new WebClient();
WC.Credentials = new System.Net.NetworkCredential("username", "password");
byte[] buff = WC.DownloadData(FilePath);
var SplitFileName = FilePath.Split('\\');
string FileName = "Recording_" + SplitFileName[SplitFileName.Count() - 1];
Response.AddHeader("Content-Disposition", "inline; filename=" + FileName);
MemoryStream stream = new MemoryStream(buff);
return new FileStreamResult(stream, "audio/wav");
//I have also tried:
//return File(buff, "audio/wav");
}
The audio tags look like this:
<td>
<audio controls preload='none'>
<source src='/Components/PlayFile?FilePath=[filename.wav]' type='audio/wav'>
</audio>
</td>
When running the site locally in Chrome, all the files have the length 0:00, and you can click the play button once but the file is not played. After the play button has been clicked once it is not possible to click it again. It is however possible to download the file
and play it. When running the site locally in Firefox, the files also have the length 0:00, and when you click the play button the control disappears. It is also possible to download the file in Firefox. Does anyone know what could be causing this?

Answer 1

The problem was that the audio files were in GSM format and needed to be converted to PCM. This code works:
[HttpGet]
public ActionResult PlayFile(string FilePath)
{
WebClient WC = new WebClient();
WC.Credentials = new System.Net.NetworkCredential("username", "password");
byte[] buff = WC.DownloadData(FilePath);
var SplitFileName = FilePath.Split('\\');
string FileName = "Recording_" + SplitFileName[SplitFileName.Count() - 1];
MemoryStream ms = new MemoryStream();
ms.Write(buff, 0, buff.Length);
ms.Seek(0, SeekOrigin.Begin);
MemoryStream outputStream = new MemoryStream();
using (NAudio.Wave.WaveFileReader reader = new WaveFileReader(ms))
using (NAudio.Wave.WaveStream waveStream = NAudio.Wave.WaveFormatConversionStream.CreatePcmStream(reader))
using (NAudio.Wave.WaveFileWriter waveFileWriter = new WaveFileWriter(outputStream, waveStream.WaveFormat))
{
byte[] bytes = new byte[waveStream.Length];
waveStream.Position = 0;
waveStream.Read(bytes, 0, (int)waveStream.Length);
waveFileWriter.Write(bytes, 0, bytes.Length);
waveFileWriter.Flush();
}
return File(outputStream.ToArray(), "audio/wav");
}

Answer 2

Can you try with below as its working for me.
public FileResult PlayFile(string FilePath)
{
return new FilePathResult(FilePath, "audio/wav");
}
Also, try changing "audio/wav" to "audio/mp3", if it helps.