The flight of the fly, second part/ El vuelo de la mosca, segunda parte

Vamos a hacer el paso inverso. Partimos de una canción y la pasamos a wav. Esto lo hacemos con cualquier convertidor de sonido a wav. La razón de utilizar un archivo wav es la facilidad de abrir tal tipo de archivo sin compresión.

Let's do the reverse step. We start with a song and pass it to wav. We do this with any audio to wav converter. The reason for using a wav file is the ease of opening such files without compression.

Utilizaremos Visual Basic 6. Lo primero son las definiciones:

We will use Visual Basic 6. The first are the definitions:

Private Const SND_ALIAS = &H10000

Private Const SND_ALIAS_ID = &H110000

Private Const SND_ALIAS_START = 0

Private Const SND_APPLICATION = &H80

Private Const SND_ASYNC = &H1

Private Const SND_FILENAME = &H20000

Private Const SND_LOOP = &H8

Private Const SND_MEMORY = &H4

Private Const SND_NODEFAULT = &H2

Private Const SND_NOSTOP = &H10

Private Const SND_NOWAIT = &H2000

Private Const SND_PURGE = &H40

Private Const SND_RESERVED = &HFF000000

Private Const SND_RESOURCE = &H40004

Private Const SND_SYNC = &H0

Private Const SND_TYPE_MASK = &H170007

Private Const SND_VALID = &H1F

Private Const SND_VALIDFLAGS = &H17201F

Private Declare Function PlaySoundFile Lib "winmm.dll" Alias "PlaySoundA" (ByVal lpszName As String, ByVal hModule As Long, ByVal dwFlags As Long) As Long

Private Declare Function PlaySoundMemory Lib "winmm.dll" Alias "PlaySoundA" (ptrMemory As Any, ByVal hModule As Long, ByVal dwFlags As Long) As Long

Private Declare Function playSound Lib "winmm.dll" Alias "PlaySoundA" (ByVal sndToPlay As String, ByVal handleModule As Long, ByVal PS_Flags As Long) As Long

Type WaveHeader

  riff As String * 4

  riffdatasize As Long 

  wave As String * 4

End Type

  

Type WaveFormat

  fmt As String * 4 

  formatsize As Long

  formatTag As Integer 

  nChannels As Integer ' for mono the value is 1.

  samplesPerSecond As Long ' 44100 means cd quality sound

  aveBytesPerSecond As Long 

  blockAlign As Integer 

  bitsPerSample As Integer

End Type

Private Type WaveDatachunk

  dataposition As String * 4 

  wavedatasize As Long 

End Type

  

  Dim wh As WaveHeader

  Dim wf As WaveFormat

  Dim dc As WaveDatachunk

  

  Dim filename As String

  Const MusicMultiplicationFactor As Double = 2 ^ (1 / 12) 

  Const PI As Double = 3.14159265358979

  Dim Esc As Single

  Dim BaseFrequency As Single

 Dim Frequency As Single  Dim Amplitude As Single

  Dim DataValue() As Integer

Lo segundo es la lectura del archivo wav:

The second is reading the wav-file:

Sub Lectura_y_Dibujo()

 Esc = Val(Text1) 'Multiplicador para ajustarnos a la escala

  'iniciamos el objeto Picture1

 Picture3.Cls: Picture1.ScaleWidth=2000: Picture1.ScaleHeight=2000: Picture1.DrawWith=2

  'Diálogo para abrir un fichero

 cd1.Filter = "Sonidos (*.wav)|*.wav"

 cd1.ShowOpen: fichero = cd1.filename

 Open fichero For Binary As #1

    Get #1, , wh

    Get #1, , wf

    Get #1, , dc

  'Abrimos un cacho del fichero

    dc.wavedatasize = 1000000

    ReDim DataValue(dc.wavedatasize)

    uu = 0: cal = QBColor(14)

    For i = 1 To dc.wavedatasize / 2 / 2

      j = (i - 1) * 2

      Get #1, , DataValue(j)

      x = Esc * DataValue(j) / 32.768 + 500

  'Picture4 es un objeto con el dibujo del arco iris de 17985 puntos de ancho    

      colo = Picture4.Point((i Mod 1000) / 1000 * 17985, 1)

      Get #1, , DataValue(j + 1)

      y = Esc * DataValue(j + 1) / 32.768 + 500

      Picture1.Line (X1, Y1)-(x, y), colo

      t = i Mod 1000: t2 = t / 2 + 1000: t1 = (t - 1) / 2 + 1000

      Picture1.DrawWidth = 2

      Picture1.Line (t1, Y1)-(t2, y), colo

      Picture1.Line (X1, t1)-(x, t2), colo

      Picture1.Line (X1, Y1)-(x, y), colo

      X1 = x: Y1 = y

       If i Mod 2 = 0 Then

         If t = 0 Then Picture1.Cls: X1 = 500: Y1 = 500

         Lineaf x, y, t2, y, cal

         Lineaf x, y, x, t2, cal

         DoEvents

        'If i Mod 2 = 0 Then SavePicture Picture1.Image, "D:\dibus\" & Format(uu, "000000") & ".bmp": uu = uu + 1

         Lineaf x, y, t2, y, cal

         Lineaf x, y, x, t2, cal

         If i Mod 10000 = 0 Then Picture1.Cls: Picture1.PSet (500, 500): '  Stop

    End If

      Next i

Close #1

End Sub

Sub Lineaf(ByVal n As Integer, ByVal m As Integer, ByVal p As   'Para hacer que aparezca y desaparezca las líneas de seguimiento

Integer, ByVal q As Integer, ByVal cu As Long)

Picture1.DrawMode = 7:Picture1.DrawWidth = 2

Picture1.Line (n, m)-(p, q), cu

Picture1.DrawWidth = 1:Picture1.DrawMode = 13

End Sub

Un ejemplo / An example:

Para una balada de XXXXX (no digo ni el autor ni la canción para no tener problemas de derechos de autor. Sólo digo que se trata de una balada Heavy:

This is graph obtained from transcribing 1 second a heavy ballad: