Registrare il sonoro da una fonte esterna e salvarlo in un file audio mediante il Componente gb.media

Il Componente gb.media consente mediante appositi plugin di GStreamer di registrare una fonte sonora esterna (ad esempio da un microfono) e salvare, quanto registrato, in un file audio.

Mostriamo di seguito alcuni casi con applicazioni a riga di comando, nei quali per interrompere la registrazione è sufficiente premere il tasto "Invio".

Salvare la registrazione in un file audio WAV (44100 hertz, mono, 16-bit)

Private bo As Boolean


Public Sub Main()
 
 Dim pl As MediaPipeline
 Dim src, aco, wen, snk As MediaControl
 Dim primofile As String
  
  primofile = "/tmp/primofile.wav"
  bo = True
  
  pl = New MediaPipeline 
  
  src = New MediaControl(pl, "alsasrc")   
  aco = New MediaControl(pl, "audioconvert")
  wen = New MediaControl(pl, "wavenc")
  snk = New MediaControl(pl, "filesink")
  snk["location"] = primofile
  
  src.LinkTo(aco)
  aco.LinkTo(wen)
  wen.LinkTo(snk)
  
  pl.Play()
  
  While bo
    Write #File.Out, "\rTempo: " & Date(0, 0, 0, 0, 0, 0, pl.Position * 1000)
    Wait 0.001
  Wend
  
  Copy primofile To "/tmp/audio.wav"
  
  pl.Stop()
  pl.Close()
  Print "Termine registrazione"
  Quit
  
End


Public Sub Application_Read()
 
 Dim s As String
 
  Input s
  
  bo = False
  
End

Salvare la registrazione in un file audio WAV (44100 hertz, stereo, 16-bit)

Private bo As Boolean


Public Sub Main()
 
 Dim pl As MediaPipeline
 Dim src, aco, wen, snk As MediaControl
 Dim flt As MediaFilter
 Dim primofile As String
  
  primofile = "/tmp/primofile.wav"
  bo = True
  
  pl = New MediaPipeline 
  
  src = New MediaControl(pl, "alsasrc")   
  aco = New MediaControl(pl, "audioconvert")
  flt = New MediaControl(pl, "audio/x-raw,rate=44100,depth=16,channels=2,width=16,signed=true")
  wen = New MediaControl(pl, "wavenc")
  snk = New MediaControl(pl, "filesink")
  snk["location"] = primofile
  
  src.LinkTo(aco)
  aco.LinkTo(aud)
  aud.LinkTo(wen)
  wen.LinkTo(snk)
  
  pl.Play()
  
  While bo
    Write #File.Out, "\rTempo: " & Date(0, 0, 0, 0, 0, 0, pl.Position * 1000)
    Wait 0.001
  Wend
  
  Copy primofile To "/tmp/audio.wav"
  
  pl.Stop()
  pl.Close()
  Print "Termine registrazione"
  Quit
  
End


Public Sub Application_Read()
 
 Dim s As String
 
  Input s
  
  bo = False
  
End

Salvare la registrazione in un file audio MP3

Private bo As Boolean


Public Sub Main()
 
 Dim pl As MediaPipeline
 Dim src, aco, len, snk As MediaControl
 Dim primofile As String
  
  primofile = "/tmp/primofile.mp3"
  bo = True
  
  pl = New MediaPipeline 
  
  src = New MediaControl(pl, "alsasrc")   
  aco = New MediaControl(pl, "audioconvert")
  len = New MediaControl(pl, "lamemp3enc")
  snk = New MediaControl(pl, "filesink")
  snk["location"] = primofile
  
  src.LinkTo(aco)
  aco.LinkTo(len)
  len.LinkTo(snk)
  
  pl.Play()
  
  While bo
    Write #File.Out, "\rTempo: " & Date(0, 0, 0, 0, 0, 0, pl.Position * 1000)
    Wait 0.001
  Wend
  
  Copy primofile To "/tmp/audio.mp3"
  
  pl.Stop()
  pl.Close()
  Print "Termine registrazione"
  Quit
  
End


Public Sub Application_Read()
 
 Dim s As String
 
  Input s
  
  bo = False
  
End

Salvare la registrazione in un file audio OGG

Private bo As Boolean


Public Sub Main()
 
 Dim pl As MediaPipeline
 Dim src, aco, ven, omu, snk As MediaControl
 Dim primofile As String
  
  primofile = "/tmp/primofile.ogg"
  bo = True
  
  pl = New MediaPipeline 
  
  src = New MediaControl(pl, "alsasrc")   
  aco = New MediaControl(pl, "audioconvert")
  ven = New MediaControl(pl, "vorbisenc")
  omu = New MediaControl(pl, "oggmux")
  snk = New MediaControl(pl, "filesink")
  snk["location"] = primofile
  
  src.LinkTo(aco)
  aco.LinkTo(ven)
  ven.LinkTo(omu)
  omu.LinkTo(snk)
  
  pl.Play()
  
  While bo
    Write #File.Out, "\rTempo: " & Date(0, 0, 0, 0, 0, 0, pl.Position * 1000)
    Wait 0.001
  Wend
  
  Copy primofile To "/tmp/audio.ogg"
  
  pl.Stop()
  pl.Close()
  Print "Termine registrazione"
  Quit
  
End


Public Sub Application_Read()
 
 Dim s As String
 
  Input s
  
  bo = False
  
End