DOCUMENT:Q147654 11-JAN-2001 [vbwin] TITLE :HOWTO: Get or Create a Unique Audio CD Volume Label PRODUCT :Microsoft Visual Basic for Windows PROD/VER: OPER/SYS: KEYWORDS:kbGrpDSVB ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Learning Edition for Windows, version 6.0 - Microsoft Visual Basic Professional Edition for Windows, version 6.0 - Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 - Microsoft Visual Basic Standard Edition for Windows, version 4.0 - Microsoft Visual Basic Professional Edition for Windows, version 4.0 - Microsoft Visual Basic Enterprise Edition for Windows, version 4.0 ------------------------------------------------------------------------------- SUMMARY ======= Part of the Multimedia standard calls for all Audio CDs to have a unique volume identifier following a specific (suggested) format of: XXXX-##### XXXX is the alpha vendor code, and ##### is a five-digit unique number for the CD. This information is stored on the inner track of the CD and is also usually etched on the inner edge of the inside ring of the CD. Not all manufacturers have a unique volume identifier, nor do all follow this standard volume label format. Although this is a standard, at this time the MultiMedia Application Programming Interface (API) does not have a built-in function that will retrieve this information. This article shows you how to retrieve or create this information programmatically. MORE INFORMATION ================ In order to retrieve the unique volume identifier from the CD, you need to call MSCDEX directly. The information on how to do this is contained within the MSCDEX 2.20 specification. Because some manufacturers aren't including this unique identifier on their CDs, Microsoft recommends that you create a unique volume identifying number based on the track information already included on the CD. The following example shows you how. Step-by-Step Example -------------------- This example shows a method for creating a unique number to identify an audio CD based on track information. The purpose of this number is to make it possible for Visual Basic programs to recognize a loaded CD and retrieve information from it. 1. Start a new project in Visual Basic. Form1 is created by default. 2. Add a text box (Text1) and a Microsoft Multimedia control (MMControl1) to Form1. 3. Place the following code in the Form_Load event of Form1: Private Sub Form_Load () Dim DiskID As Long Dim Track As Integer ' Initialize CD: mmcontrol1.DeviceType = "CDAudio" mmcontrol1.Command = "open" ' Make unique number based on tracks and tracklength: DiskID = mmcontrol1.Tracks For Track = 1 To mmcontrol1.Tracks mmcontrol1.Track = Track DiskID = DiskID + mmcontrol1.TrackLength ' Add 4-byte TrackLength DiskID = DiskID + mmcontrol1.Length ' Add 4-byte CD Length Next Track ' Set text to unique value: Text1.Text = DiskID End Sub 4. Load a CD. 5. Start the program, or press the F5 key. 6. The Text1 box should have a unique identifying number for the CD. NOTE: Before starting the program, a CD must be inserted and ready to play. Therefore, you should add code to detect when a CD has been inserted and then run the above code. REFERENCES ========== For more information, see the MultiMedia Programmer's Reference, CDAudio Additional query words: kbVBp400 kbVBp500 kbVBp600 kbMM kbVBp kbdsd kbDSupport ====================================================================== Keywords : kbGrpDSVB Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVBA600 kbVB600 kbVB400Search kbVB400 Issue type : kbhowto ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.