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How to get the virtual series number of an audio CD (Views: 100)


Problem/Question/Abstract:

How to get the virtual series number of an audio CD

Answer:

Answer 1:

Windows creates a "Virtual Series Number" for Audio CDs. You can use the following code to get the VSN of an audio CD:

type
  TNumbBase = 1..36;

function NumbToStr(Numb: LongInt; Base: TNumbBase): string;
const
  NumbDigits = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
begin
  Result := EmptyStr;
  while Numb > 0 do
  begin
    Result := NumbDigits[(Numb mod Base) + 1] + Result;
    Numb := Numb div Base;
  end;
  if Result = EmptyStr then
    Result := '0';
end;

function GetCDID(Drive: string): string;
var
  Serial: DWord;
  T: Cardinal;
begin
  if GetVolumeInformation(PChar(Drive), nil, 0, @Serial, T, T, nil, 0) then
    Result := NumbToStr(Serial, 16)
  else
    Result := EmptyStr;
end;

Drive should be the name of the root directory of your CD drive. Use it like

ShowMessage(GetCDID('I:\'));

or

ShowMessage(GetCDID('\\Computer2\\CDDrive\'));


Solve 2:

You have to use the API-call GetVolumeInformation. But first, you have to implement it correctly:


function GetVolumeInformation(lpRootPathName: PAnsiChar; lpVolumeNameBuffer: PAnsiChar; nVolumeNameSize: DWORD; var lpVolumeSerialNumber, lpMaximumComponentLength,
lpFileSystemFlags: DWORD; lpFileSystemNameBuffer: PAnsiChar; nFileSystemNameSize: DWORD): bool; stdcall; external kernel32 name 'GetVolumeInformationA';


In your application:


function GetCDId: string;
var
  root: string;
  VolumeNameBuffer, FileSystemNameBuffer: PChar;
  VolumeSerialNumber, FileSystemFlags, MaximumComponentLength: LongInt;

  function Int2Hex(number: LongInt): string;
  var
    i: LongInt;
    s: string;
  begin
    s := '';
    i := 0;
    while number > 0 do
    begin
      i := number mod 16;
      case i of
        0..9: s := IntToStr(i) + s;
        10: s := 'A' + s;
        11: s := 'B' + s;
        12: s := 'C' + s;
        13: s := 'D' + s;
        14: s := 'E' + s;
        15: s := 'F' + s;
      end;
      number := number - i * 16;
    end;
    Result := s;
  end;

begin
  root := 'x:\'; {where X is the drive letter of your CD drive}
  VolumeNameBuffer := StrAlloc(256);
  FileSystemNameBuffer := StrAlloc(256);
  if GetVolumeInformation(PChar(root), VolumeNameBuffer, 255, VolumeSerialNumber,
    MaximumComponentLength, FileSystemFlags, FileSystemNameBuffer, 255) then
    Result := Int2Hex(VolumeSerialNumber);
else
  Result := '';
end;

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