Ok, I started from scratch now :)
After a while I seemed to be close to the solution... There is something I do not understand about bass...
When I need to retreive 5 seconds (f.e.: 44100*5) I needed to increase this value by 2, even if the stream was mono.
In the example bellow it seemed to work at first, but when I retreived the delta sample data (data needed to compleet the waveform) I retreived only half the amount I needed, even if I multiplied by 2... I don't really know why...
The result was a waveform that was stretched 2x in time after the first build (of the full 5 seconds) has passed.
To counteract this effect, i simply decreased the avgSize by 2 calculating medium values over half only half the first wave data...
Anyway, it works now, here is the code...
'general declarations
Public vALastPos As Long 'Position when last data was retr.
Public vALastArr() As Integer 'Last data retreived
Public vALastSize As Long 'Last size of data retreived
Public vADelta As Long 'The size of the data that tobe added
Public vADeltaGraf As Long 'The last graph data
'This array contains the waveform for it's predefined length
'From 0 to 100...
'At 50ms do the calculations...
Dim mPos As Single 'used to get the music position in sec
Dim fPos As Long 'Actual position of decoding stream (mono)
Dim bufSize As Long 'Buffer data size used
Dim arr() As Integer 'Temporary array of new data
Dim avgSize As Long 'Size of data that is covered when
'calculating the average value of the wavedata
Dim res As Integer 'Resolution of calculating the aver.data
Dim m As Long 'Loop index value
Dim mOff As Long 'Used to hold the offset of an arr in loop
bufSize = 44100 * 4 'Set the size of the buffer
'Seek current position
mPos = BASS_ChannelBytes2Seconds(hA, BASS_ChannelGetPosition(hA))
fPos = BASS_ChannelSeconds2Bytes(hDA, mPos)
'If the current position = last position, no nothing
If vALastPos = fPos Then GoTo novis
'Calculate average and resolution
avgSize = bufSize / UBound(GrfA)
'visAcuracy is the value of samples taken. 32 or 64 is a
good value... 128 is better
res = avgSize / visAcuracy '= step size in calculation
'If last position was not set, decode the whole stream
If vALastPos <= 0 Then
'Get data
BASS_ChannelSetPosition hDA, fPos
'Init the temporary array
ReDim arr(bufSize)
BASS_ChannelGetData hDA, arr(0), bufSize * 2
'Build the graph
'avgSize must be half, why???
avgSize = avgSize / 2
For m = 0 To UBound(GrfA) - 1
'This function sweeps the temp array from
m*avgsize until m*avgsize+avgsize with a step of res
GrfA(m) = (calcAvg(arr, m * avgSize, avgSize, res)
Next
'Set last variables to new data...
vALastPos = fPos
vALastArr = arr
vALastSize = bufSize
Else
vADelta = fPos - vALastPos
'If the stream is playing foreward and delta is not
'larger then the total buffer size
If (vADelta > 0) And (vADelta < bufSize) Then
'Get data
BASS_ChannelSetPosition hDA, vALastPos + bufSize - vADelta
ReDim arr(vADelta)
'Get the wave data that was not decoded last time
BASS_ChannelGetData hDA, arr(0), vADelta * 2
'reBuild the array
'Move the wave data by vaDelta to the left
mOff = bufSize - vADelta
For m = 0 To mOff - 1
vALastArr(m) = vALastArr(m + vADelta)
Next
'Add the new wave data to the end
For m = mOff To bufSize
vALastArr(m) = arr(m - mOff)
Next
arr = vALastArr
'Build the graph
'Calc what size the new graphic data has
vADeltaGraf = vADelta / bufSize * UBound(GrfA)
'Move the graphic by DeltaGraph to the left
For m = 0 To (UBound(GrfA) - vADeltaGraf - 1)
'Calc median...
GrfA(m) = GrfA(m + vADeltaGraf)
Next
'Add the new graphic data
For m = (UBound(GrfA) - vADeltaGraf) To UBound(GrfA) - 1
'Calc median...
GrfA(m) = (calcAvg(arr, m * avgSize, avgSize, res)
Next
'Update "last" variables
vALastPos = fPos
vALastSize = bufSize
Else
'if not, order the full graphic decoding next time
vALastPos = 0
End If
End If
