Visual Basic MCI Control TimeFormat Property Information (94012)


The information in this article applies to:

  • Microsoft Professional Toolkit for Microsoft Visual Basic programming system for Windows
  • Microsoft Visual Basic Professional Edition for Windows 2.0
This article was previously published under Q94012

SUMMARY

The Multimedia Device Control (MCI.VBX) TimeFormat property does not support all format settings with all device types. When you assign a value to TimeFormat that is not supported by the device, the TimeFormat retains its previous setting.

This article also describes MCI_FORMAT_MSF (2) and shows how to separate the four bytes of a time value.

MORE INFORMATION

To determine if the current device supports a particular TimeFormat setting, assign the value to TimeFormat. Then check TimeFormat to see if it returns the value assigned. For example: 
   For i = 0 To 10
      MMControl1.TimeFormat = i
      If MMControl1.TimeFormat = i Then
         MsgBox Format$(i) + " supported"
      Else
         MsgBox Format$(i) + " not supported"
      End If
   Next
Some of the time formats, such as MCI_FORMAT_TMSF, provide four separate byte size numbers packed into one four byte long integer. The following sample statements show how you can extract the four bytes into separate variables: 
   byte1 =  MMControl1.Position And       &HFF&
   byte2 = (MMControl1.Position And     &HFF00&) \     &H100
   byte3 = (MMControl1.Position And   &HFF0000)  \   &H10000
   byte4 = (MMControl1.Position And &H7F000000)  \ &H1000000
   If (MMControl1.Position And &H80000000) <> 0 Then
      ' put sign bit back into byte4
      byte4 = byte4 + &H80
   End If
The least significant byte is stored in byte1 and the most significant byte is stored in byte4.

The following list shows all possible settings for TimeFormat:

0 MCI_FORMAT_MILLISECONDS
1 MCI_FORMAT_HMS
2 MCI_FORMAT_MSF
3 MCI_FORMAT_FRAMES
4 MCI_FORMAT_SMPTE_24
5 MCI_FORMAT_SMPTE_25
6 MCI_FORMAT_SMPTE_30
7 MCI_FORMAT_SMPTE_30DROP
8 MCI_FORMAT_BYTES
9 MCI_FORMAT_SAMPLES
10 MCI_FORMAT_TMSF

The TimeFormat setting MCI_FORMAT_MSF is described in the README.TXT file but is missing from the "Microsoft Visual Basic Professional Features Custom Control Reference" for version 2.0. The following description of MCI_FORMAT_MSF appears in the README.TXT file:

2 MCI_FORMAT_MSF Minutes, seconds, and frames are packed into a
four-byte integer. From least significant byte to
most significant byte, the individual data values
follow:

Minutes (least significant byte)
Seconds
Frames
Unused (most significant byte)

The TimeFormat property affects the following properties.

Position
From
To
Start
Length
TrackLength
TrackPosition

Microsoft has confirmed that this information should be included in the "Microsoft Visual Basic Professional Features Custom Control Reference" for version 2.0. We will post new information here when the documentation has been updated with this additional information.
Modification Type:MinorLast Reviewed:8/16/2005
Keywords:KB94012
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