BASS_FILEPROCS Class

[SerializableAttribute]
[StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public sealed class BASS_FILEPROCS

<SerializableAttribute>
<StructLayoutAttribute(LayoutKind.Sequential, CharSet := CharSet.Ansi)>
Public NotInheritable Class BASS_FILEPROCS

using Un4seen.Bass;
...
private BASS_FILEPROCS _myStreamCreateUser;
private FileStream _fs;
...
Bass.BASS_Init(-1, 44100, BASSInit.BASS_DEVICE_DEFAULT, this.Handle);
// creating the user file callback delegates
_myStreamCreateUser = new BASS_FILEPROCS(
    new FILECLOSEPROC(MyFileProcUserClose), 
    new FILELENPROC(MyFileProcUserLength), 
    new FILEREADPROC(MyFileProcUserRead), 
    new FILESEEKPROC(MyFileProcUserSeek));
// open the file...
_fs = File.OpenRead("test.mp3");
// create the stream (the PRESCAN flag shows you what BASS is doing at the beginning to scan the entire file)
// if that generates to much output for you, you can simply remove it
int stream = Bass.BASS_StreamCreateFileUser(BASSStreamSystem.STREAMFILE_NOBUFFER, BASSFlag.BASS_STREAM_PRESCAN | BASSFlag.BASS_STREAM_AUTOFREE, _myStreamCreateUser, IntPtr.Zero);
// play the channel
Bass.BASS_ChannelPlay(stream, false);
...
private void MyFileProcUserClose(IntPtr user)
{
  if (_fs == null)
    return;
  _fs.Close();
  Console.WriteLine("File Closed");
}

private long MyFileProcUserLength(IntPtr user)
{
  if (_fs == null)
    return 0L;
  return _fs.Length;
}

private int MyFileProcUserRead(IntPtr buffer, int length, IntPtr user)
{
  if (_fs == null)
    return 0;
  try
  {
    // at first we need to create a byte[] with the size of the requested length
    byte[] data = new byte[length];
    // read the file into data
    int bytesread = _fs.Read(data, 0, length);
    // and now we need to copy the data to the buffer
    // we write as many bytes as we read via the file operation
    Marshal.Copy(data, 0, buffer, bytesread);
    return bytesread;
  }
  catch { return 0; }
}

private bool MyFileProcUserSeek(long offset, IntPtr user)
{
  if (_fs == null)
    return false;
  try
  {
    long pos = _fs.Seek(offset, SeekOrigin.Begin);
    return true;
  }
  catch
  {
    return false;
  }
}

Imports Un4seen.Bass
...
Private _myStreamCreateUser As BASS_FILEPROCS
Private _fs As FileStream
...
Bass.BASS_Init(- 1, 44100, BASSInit.BASS_DEVICE_DEFAULT, Me.Handle)
' creating the user file callback delegates
_myStreamCreateUser = New BASS_FILEPROCS(
    New FILECLOSEPROC(AddressOf MyFileProcUserClose), 
    New FILELENPROC(AddressOf MyFileProcUserLength), 
    New FILEREADPROC(AddressOf MyFileProcUserRead), 
    New FILESEEKPROC(AddressOf MyFileProcUserSeek))
' open the file...
_fs = File.OpenRead("test.mp3")
' create the stream (the PRESCAN flag shows you what BASS is doing at the beginning to scan the entire file)
' if that generates to much output for you, you can simply remove it
Dim stream As Integer = Bass.BASS_StreamCreateFileUser(BASSStreamSystem.STREAMFILE_NOBUFFER, BASSFlag.BASS_STREAM_PRESCAN Or BASSFlag.BASS_STREAM_AUTOFREE, _myStreamCreateUser, IntPtr.Zero)
' play the channel
Bass.BASS_ChannelPlay(stream, False)
...
Private Sub MyFileProcUserClose(user As IntPtr)
  If _fs Is Nothing Then
    Return
  End If 
  _fs.Close()
End Sub

Private Function MyFileProcUserLength(user As IntPtr) As Long
  If _fs Is Nothing Then
    Return 0L
  End If 
  Return _fs.Length   
End Function

Private Function MyFileProcUserRead(buffer As IntPtr, length As Integer, user As IntPtr) As Integer
  If _fs Is Nothing Then
    Return 0
  End If 
  Try
    ' at first we need to create a byte[] with the size of the requested length
    Dim data(length - 1) As Byte
    ' read the file into data
    Dim bytesread As Integer = _fs.Read(data, 0, length)
    ' and now we need to copy the data to the buffer
    ' we write as many bytes as we read via the file operation
    Marshal.Copy(data, 0, buffer, bytesread)
    Return bytesread
  Catch
    Return 0
  End Try
End Function

Private Function MyFileProcUserSeek(offset As Long, user As IntPtr) As Boolean
  If _fs Is Nothing Then
    Return False
  End If 
  Try
    Dim pos As Long = _fs.Seek(offset, SeekOrigin.Begin)
    Return True
  Catch
    Return False
  End Try
End Function