How To Get the Total Playing Time of an Audio CD

- Standard and Professional Editions of Microsoft Visual Basic for

  Windows, version 3.0

SUMMARY

The MultiMedia Application Programming Interface (API) and the MCI Control have built-in methods that retrieve the total playing time of a CD. The Length property of the MCI Control will retrieve total playing time of the current media.

MORE INFORMATION

After setting the MCI Control's TimeFormat property to MCI_FORMAT_TMSF(10) and summing the values returned by the DateAdd function to add the total time values for minutes and seconds together, you can calculate a CD's total playing time.

DateAdd starts adding from 12:00:00 AM, so you need to check to see if the total time is less than one hour. If it is, strip off the first three characters (12:) and the AM. If the time is greater than one hour, strip off the AM so that the return value looks like this:

1:09:43

• or -

Step-by-Step Example

1. Start a new project in Visual Basic. Form1 is created by default.

2. Add a text box (Text1) and an MCI Control (MMControl1) to Form1.

3. Place the following code in the Form_Load event of Form1:

      Sub Form_Load ()
         ' Initialize the CD:
         mmcontrol1.TimeFormat = 10
         mmcontrol1.DeviceType = "CDAudio"
         mmcontrol1.Command = "Open"
         ' Dimension variables:
         Dim Length As Variant
         Dim CDSeconds As Integer, CDMinutes As Integer
         ' Calculate minutes and seconds:
         CDSeconds = CDSeconds + (mmcontrol1.Length And &HFF00&) / &H100
         CDMinutes = CDMinutes + (mmcontrol1.Length And &HFF)
         ' Sum minutes and seconds:
         Length = DateAdd("s", CDSeconds, Length) ' Add Seconds
         Length = DateAdd("n", CDMinutes, Length) ' Add Minutes
         ' Determine if total running time is less than one hour:
         If (Left$(Length, 2)) = "12" Then ' Less than 1 hour
            Text1.Text = Mid(Length, 4, (Len(Length) - 4))
         Else ' Greater than 1 hour:
            Text1.Text = Left(Length, (Len(Length) - 3))
         End If
      End Sub
   
   

4. Run the program. You should see the total playing displayed in the Text1 box.

REFERENCES

For more information, see the Multimedia Programmer's Reference, CDAudio