Differenze tra le versioni di "Ottenere un file WAV da un file Midi con la funzione esterna ''gst parse launch()'' del API di GStreamer"

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E' possibile ottenere un file audio formato WAV da un file Midi mediante una linea di pipeline gestita dalla funzione ''gst parse launch()'' del API di ''GStreamer''.
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E' possibile ottenere un file audio formato WAV da un file Midi mediante una linea di pipeline gestita dalla funzione "gst parse launch()" del API di ''GStreamer''.
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<BR>E' necessario avere installa nel proprio sistema la libreria condivisa: "''libgstreamer-1.0'' ".
  
 
Mostriamo un esempio pratico:
 
Mostriamo un esempio pratico:
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Private midi As Pointer
 
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  Library "libgstreamer-1.0"
 
  Library "libgstreamer-1.0"
 
   
 
   
 
  Private Enum GST_STATE_VOID_PENDING = 0, GST_STATE_NULL, GST_STATE_READY, GST_STATE_PAUSED, GST_STATE_PLAYING
 
  Private Enum GST_STATE_VOID_PENDING = 0, GST_STATE_NULL, GST_STATE_READY, GST_STATE_PAUSED, GST_STATE_PLAYING
 
  Private Const GST_FORMAT_TIME As Integer = 3
 
  Private Const GST_FORMAT_TIME As Integer = 3
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Private stato As Integer = GST_STATE_PLAYING
 
 
   
 
   
 
  <FONT Color=gray>' ''gst_init (int *argc, char **argv[])''
 
  <FONT Color=gray>' ''gst_init (int *argc, char **argv[])''
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  ' ''Queries an element for the total stream duration in nanoseconds.''</font>
 
  ' ''Queries an element for the total stream duration in nanoseconds.''</font>
 
  Private Extern gst_element_query_duration(gselement As Pointer, formatI As Integer, duration As Pointer) As Boolean
 
  Private Extern gst_element_query_duration(gselement As Pointer, formatI As Integer, duration As Pointer) As Boolean
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  <FONT Color=gray>' ''gboolean gst_element_query_position (GstElement *element, GstFormat format, gint64 *cur)''
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  <FONT color=gray>' ''gboolean gst_element_query_position (GstElement *element, GstFormat format, gint64 *duration)''
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  ' ''Queries an element for the stream position in nanoseconds.''</font>
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  ' ''Queries an element for the total stream position in nanoseconds.''</font>
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  Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, cur As Pointer) As Boolean
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  Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, position As Pointer) As Boolean
 
   
 
   
 
  <FONT Color=gray>' ''void gst_object_unref(gpointer object)''
 
  <FONT Color=gray>' ''void gst_object_unref(gpointer object)''
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  '''Public''' Sub Main()
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  Public Sub Main()
 
    
 
    
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   Dim posizione, durata As Long
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   Dim midi As Pointer
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   Dim dur, pos As Date
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  Dim volume As Float
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  Dim durata, l As Long
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  gst_init(0, 0)
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   Dim tm As Date
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  gst_init(0, 0)
 
    
 
    
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  midi = gst_parse_launch("filesrc location=<FONT Color=gray>''/percorso/del/file.mid''</font> ! decodebin ! audioconvert ! audioresample ! volume volume=7.0 ! wavenc ! filesink location =/tmp/file.wav", 0)
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  midi = gst_parse_launch("filesrc location=<FONT Color=darkgreen>''/percorso/del/file.mid''</font> ! decodebin ! audioconvert ! audioresample ! volume volume=7.0 ! wavenc ! filesink location =/tmp/file.wav", 0)
 
          
 
          
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  <FONT Color=gray>' ''Avviamo la riproduzione del file Midi:''</font>
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  <FONT Color=gray>' ''Avviamo la riproduzione del file Midi per la creazione del file audio WAV:''</font>
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  gst_element_set_state(midi, GST_STATE_PLAYING)
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  gst_element_set_state(midi, GST_STATE_PLAYING)
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  While stato = GST_STATE_PLAYING
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  Repeat
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    gst_element_query_duration(midi, GST_FORMAT_TIME, VarPtr(durata))
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    gst_element_query_duration(midi, GST_FORMAT_TIME, VarPtr(durata))
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    gst_element_query_position(midi, GST_FORMAT_TIME, VarPtr(posizione))
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    Wait 0.01
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    dur = Date(0, 0, 0, 0, 0, 0, durata / 1000000)
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  Until durata > -1
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    pos = Date(0, 0, 0, 0, 0, 0, posizione / 1000000)
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    If (posizione > 0) And (pos >= dur) Then Break
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  tm = Now
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    Write #File.Out, "\rDurata: " & Date(0, 0, 0, 0, 0, 0, durata / 1000000) & "      Pos. " & Date(0, 0, 0, 0, 0, 0, posizione / 1000000)
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    Wait 0.01
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  Repeat
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  Wend
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    l = DateDiff(tm, Now, gb.Millisecond)
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    Write "\r\e[0mDurata: " & Time(0, 0, 0, durata / 1000000) & "      Pos. \e[31m" & Time(0, 0, 0, l)
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  gst_object_unref(midi)
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    Wait 0.001
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  Print "\nEsecuzione terminata."
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  Until l >= durata / 1000000
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  Quit
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  gst_object_unref(midi)
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  Print "\nCreazione del file audio WAV terminata."
 
        
 
        
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  '''End'''
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  End
  
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===Uso dei plugin specifici di ''GStreamer'' per il Midi===
 +
Si potrà anche far uso dei plugin specifici di ''GStreamer'' per il Midi, che sono:
 +
* ''midiparse''
 +
* ''fluiddec''
 +
In tal caso la stringa della pipeline dei plugin del codice, sopra esposto, sarà la seguente:
 +
midi = gst_parse_launch("filesrc location=<FONT Color=darkgreen>''/percorso/del/file.mid''</font> ! <FONT Color=#B22222>midiparse</font> ! <FONT Color=#B22222>fluiddec</font> ! audioconvert ! audioresample ! volume volume=7.0 ! wavenc ! filesink location =/tmp/file.wav", 0)
  
  

Versione attuale delle 16:21, 13 gen 2024

E' possibile ottenere un file audio formato WAV da un file Midi mediante una linea di pipeline gestita dalla funzione "gst parse launch()" del API di GStreamer.
E' necessario avere installa nel proprio sistema la libreria condivisa: "libgstreamer-1.0 ".

Mostriamo un esempio pratico: 

Library "libgstreamer-1.0"

Private Enum GST_STATE_VOID_PENDING = 0, GST_STATE_NULL, GST_STATE_READY, GST_STATE_PAUSED, GST_STATE_PLAYING
Private Const GST_FORMAT_TIME As Integer = 3

' gst_init (int *argc, char **argv[])
' Initializes the GStreamer library, setting up internal path lists, registering built-in elements, and loading standard plugins.
Private Extern gst_init(argc As Pointer, argv As Pointer)

' GstElement * gst_parse_launch (const gchar *pipeline_description, GError **error)
' Create a new pipeline based on command line syntax.
Private Extern gst_parse_launch(description As String, GError As Pointer) As Pointer

' GstStateChangeReturn gst_element_set_state(GstElement *element, GstState state)
' Sets the state of the element.
Private Extern gst_element_set_state(gstelement As Pointer, state As Integer) As Integer

' gboolean gst_element_query_duration(GstElement *element, GstFormat format, gint64 *duration)
' Queries an element for the total stream duration in nanoseconds.
Private Extern gst_element_query_duration(gselement As Pointer, formatI As Integer, duration As Pointer) As Boolean

' gboolean gst_element_query_position (GstElement *element, GstFormat format, gint64 *duration)
' Queries an element for the total stream position in nanoseconds.
Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, position As Pointer) As Boolean

' void gst_object_unref(gpointer object)
' Decrements the reference count on object.
Private Extern gst_object_unref(gobject As Pointer)


Public Sub Main()
 
 Dim midi As Pointer
 Dim volume As Float
 Dim durata, l As Long
 Dim tm As Date

 gst_init(0, 0)
  
 midi = gst_parse_launch("filesrc location=/percorso/del/file.mid ! decodebin ! audioconvert ! audioresample ! volume volume=7.0 ! wavenc ! filesink location =/tmp/file.wav", 0)
       
' Avviamo la riproduzione del file Midi per la creazione del file audio WAV:
 gst_element_set_state(midi, GST_STATE_PLAYING)
 
 Repeat
   gst_element_query_duration(midi, GST_FORMAT_TIME, VarPtr(durata))
   Wait 0.01
 Until durata > -1

 tm = Now

 Repeat
   l = DateDiff(tm, Now, gb.Millisecond)
   Write "\r\e[0mDurata: " & Time(0, 0, 0, durata / 1000000) & "      Pos. \e[31m" & Time(0, 0, 0, l)
   Wait 0.001
 Until l >= durata / 1000000

 gst_object_unref(midi)
 Print "\nCreazione del file audio WAV terminata."
      
End

Uso dei plugin specifici di GStreamer per il Midi

Si potrà anche far uso dei plugin specifici di GStreamer per il Midi, che sono:

  • midiparse
  • fluiddec

In tal caso la stringa della pipeline dei plugin del codice, sopra esposto, sarà la seguente: 

midi = gst_parse_launch("filesrc location=/percorso/del/file.mid ! midiparse ! fluiddec ! audioconvert ! audioresample ! volume volume=7.0 ! wavenc ! filesink location =/tmp/file.wav", 0)


Riferimenti

Estratto da "https://www.gambas-it.org/wiki/index.php?title=Ottenere_un_file_WAV_da_un_file_Midi_con_la_funzione_esterna_%27%27gst_parse_launch()%27%27_del_API_di_GStreamer&oldid=36189"