Calculating progress speed using byte count of data

[jmsrickland]

I hope I can explain this well enough but here is my problem.

I am using two pictureboxes to show the progress of a sound as it is being played. Picture2 is the background that holds an image in it. It does not move. Picture1 is sitting on top of Picture2 (not in Picture2 like a Child) and it is to move from left to right until it's left border has moved all the way to the right border of Picture2 thus exposing the image underneath it.

I know how many bytes of data are in the sound file and as the sound is being played I can capture the number of bytes that have been played using a Timer event.

I need to take the number of bytes already played and using that calculate how much movement should be applied to Picture1 so it moves right a certain amount of distance and it will have moved all the way to the right when the return value of bytes played is equal to the number of bytes in the sound file.

[Lenggries]

I am assuming the following:
Picture1.Left = Picture2.Left when the song begins
lngBytesPlayed is total number of bytes you have "captured"
lngTotalBytes is the total size of the sound file

   Picture1.Left = Picture2.Left + ((lngBytesPlayed * Picture2.Width) / lngTotalBytes)

Please note, however, there may not be a one for one correlation consumption of bytes of the sound file and the actual pace of music. In other words, the first 10 seconds of a song file may take up more or less memory than the middle 10 seconds, which would cause the background image to be revealed at an uneven pace. A better method would be to use calculate and use time elapsed and total song length instead of lngBytesPlayed and lngTotalBytes, respectively.

[jmsrickland]

Yes, I agree with you about using time elapsed and total length to get an even pace but maybe it doesn't really matter. I would think that the return bytes used varies and this would influence how much Picture1 moves either a very small amount or a bigger anount of distance. Let's say the first 10 seconds takes up half the total size in bytes and the next 30 seconds take up the last half of the total size. This would result in Picture1 moving faster in the first 10 seconds then it slows down in the next 30 seconds. Yes, it's an uneven pace as you state but maybe that wont matter as long as Picture1 reaches the end at the same time the song ends.

However I would have preferred to use the time elapsed instead so as to get an even pace. I can capture the time elapsed in millisecond however I do not know how to get the total time duration of the sound file prior to playing the sound. I am using waveIn and waveOut and I have not been able to find a MM method or API the get the total length in time of the sound file without having to play it first. I get the total number of bytes because that is the size of the sound file minus the header size.

[RhinoBull]

You can use FileLen() function to get file size without playing it:

Debug.Print FileLen("C:\Temp\REMINDER.WAV")

That will give you total in bytes (if it helps).

[jmsrickland]

I already know total bytes without playing it. You didn't read my post correctly. It's the total length in time I can't get without playing it first.

[RhinoBull]

Well, what you can do is use this sample to get file extended info and then calculate how long it's going to play using code below (it's extended sample from that link):

Private Sub Command1_Click()
Dim rInfo As WAVInfo
Dim targetWav As String
Dim totalBytes As Long
Dim wavLength As Long

    targetWav = "C:\Temp\REMINDER.WAV"
    
    totalBytes = FileLen(targetWav)
    
    If GetWaveInfo(targetWav, rInfo) Then
        Debug.Print rInfo.AverageBytesPerSecond
        wavLength = totalBytes / rInfo.AverageBytesPerSecond
        Debug.Print "File playtime in seconds: " & wavLength
    End If

End Sub

[RhinoBull]

Also, if interested read this article.

[jmsrickland]

Well, what you can do is use this sample to get file extended info and then calculate how long it's going to play using code below (it's extended sample from that link):

Private Sub Command1_Click()
Dim rInfo As WAVInfo
Dim targetWav As String
Dim totalBytes As Long
Dim wavLength As Long

    targetWav = "C:\Temp\REMINDER.WAV"
    
    totalBytes = FileLen(targetWav)
    
    If GetWaveInfo(targetWav, rInfo) Then
        Debug.Print rInfo.AverageBytesPerSecond
        wavLength = totalBytes / rInfo.AverageBytesPerSecond
        Debug.Print "File playtime in seconds: " & wavLength
    End If

End Sub

Absolutely!. That's exactly what I have been looking for. Thanks RB, very appreciative.

[jmsrickland]

Also, if interested read this article.

Look really neat but as usual when I download from VBA there's always something not quit right. When I go to run it I get error:

Code in vbalWaveRender.cls

Object variable or With block variable not set

  '
  '
Private Sub setScroll()
Dim lMax As Long

   m_bSetting = True

   If (m_lZoom <= 1) Then
      m_lSampleStep = 1
      m_lPixelStep = Abs(m_lZoom)
      m_lSamplePerPixelStep = 1
      lMax = m_cWAVRead.AudioLength
   Else
  '
  '
  '

[RhinoBull]

It probably requires supporting component. I'm sure there is a link somewhere...