Riproduzione dell'audio di radio WEB con le funzioni esterne del API di GStreamer
Da Gambas-it.org - Wikipedia.
Le stazioni radio via WEB possono essere ascoltate utilizzando le risorse del API di GStreamer.
Indice
Uso del plug-in playbin
Private play As Pointer
Library "libgstreamer-1.0"
Private Const GST_STATE_NULL As Integer = 1
Private Const GST_STATE_PLAYING As Integer = 4
' gst_init (&argc, &argv)
' Initializes the GStreamer library, setting up internal path lists, registering built-in elements, and loading standard plugins.
Private Extern gst_init(argc As Integer, argv As Pointer)
' GstElement * gst_element_factory_make(const gchar *factoryname, Const gchar * name)
' Create a new element of the type defined by the given element factory.
Private Extern gst_element_factory_make(factoryname As String, name As String) As Pointer
' void g_object_set(gpointer object, const gchar *first_property_name, ...)
' Sets properties on an object.
Private Extern g_object_set(gobject As Pointer, key As String, value As String, nl As String)
' GstStateChangeReturn gst_element_set_state(GstElement *element, GstState state)
' Sets the state of the element.
Private Extern gst_element_set_state(gstobject As Pointer, state As Integer) As Integer
' void gst_object_unref(gpointer object)
' Decrements the reference count on object .
Private Extern gst_object_unref(gobject As Pointer)
Public Sub Form_Open()
Dim retI As Integer
gst_init(0, 0)
play = gst_element_factory_make("playbin", "play")
' Nel terzo argomento della seguente funzione va inserito l'indirizzo web del flusso di dati audio in tempo reale:
g_object_set(play, "uri", "https://funkyradio.streamingmedia.it/audio.aac", Null)
' Avvia la riproduzione audio della radio-web:
retI = gst_element_set_state(play, GST_STATE_PLAYING)
Print "Stato di cambiamento = "; retI
End
Public Sub Button1_Click()
Dim retI As Integer
' Arresta la riproduzione audio:
retI = gst_element_set_state(play, GST_STATE_NULL)
Print "Stato di cambiamento = "; retI
gst_object_unref(play)
End
Uso della funzione gst_parse_launch( ) e il plugin "uridecodebin"
Nell'esempio, che segue, sarà sufficiente premere il tasto "Invio" per chiudere il programma.
Private bo As Boolean
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_position (GstElement *element, GstFormat format, gint64 *cur)
' Queries an element for the stream position in nanoseconds.
Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, cur 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 audio As Pointer
Dim pos As Long
gst_init(0, 0)
audio = gst_parse_launch("uridecodebin uri=http://indirizzo/del/flusso/della/radio/web/live ! audioconvert ! autoaudiosink", 0)
' Avvia l'esecuzione audio della radio web:
gst_element_set_state(audio, GST_STATE_PLAYING)
Repeat
gst_element_query_position(audio, GST_FORMAT_TIME, VarPtr(pos))
Write "\rTempo trascorso: " & Str(Time(0, 0, 0, pos / 1000000))
Wait 0.01
Until bo = True
gst_object_unref(audio)
Quit
End
Public Sub Application_Read() ' Premendo il tasto "Invio", si chiuderà il programma
bo = True
End
Riproduzione audio e finale registrazione del flusso di una radio-web in un file MP3
Private bo As Boolean
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_position (GstElement *element, GstFormat format, gint64 *cur)
' Queries an element for the stream position in nanoseconds.
Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, cur 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 audio As Pointer
Dim pos As Long
gst_init(0, 0)
audio = gst_parse_launch("uridecodebin uri=http://indirizzo/del/flusso/della/radio/web/live ! audioconvert ! tee name=radio ! queue ! autoaudiosink radio. ! queue ! lamemp3enc target=bitrate bitrate=128 cbr=true ! filesink location=/tmp/output.mp3", 0)
' Avvia l'esecuzione audio della radio web:
gst_element_set_state(audio, GST_STATE_PLAYING)
Repeat
gst_element_query_position(audio, GST_FORMAT_TIME, VarPtr(pos))
Write "\rTempo trascorso: " & Str(Time(0, 0, 0, pos / 1000000))
Wait 0.01
Until bo = True
gst_object_unref(audio)
Quit
End
Public Sub Application_Read() ' Premendo il tasto "Invio", si chiuderà il programma
bo = True
End
Uso della funzione gst_parse_launch( ) e i plugin "souphttpsrc" e "decodebin"
Nell'esempio, che segue, sarà sufficiente premere il tasto "Invio" per chiudere il programma.
Private bo As Boolean
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_position (GstElement *element, GstFormat format, gint64 *cur)
' Queries an element for the stream position in nanoseconds.
Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, cur 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 audio As Pointer
Dim pos As Long
gst_init(0, 0)
audio = gst_parse_launch("souphttpsrc location=http://indirizzo/del/flusso/della/radio/web/live ! decodebin ! audioconvert ! autoaudiosink", 0)
' Avvia l'esecuzione audio della radio web:
gst_element_set_state(audio, GST_STATE_PLAYING)
Repeat
gst_element_query_position(audio, GST_FORMAT_TIME, VarPtr(pos))
Write "\rTempo trascorso: " & Str(Time(0, 0, 0, pos / 1000000))
Wait 0.01
Until bo = True
gst_object_unref(audio)
Quit
End
Public Sub Application_Read() ' Premendo il tasto "Invio", si chiuderà il programma
bo = True
End
Uso della funzione gst_parse_launch( ) e del plugin jackaudiosink
Per l'esecuzione del seguente codice è necessario avviare preliminarmente il programma Jack.
Sarà sufficiente premere il tasto "Invio" per chiudere il programma.
Private bo As Boolean
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_position (GstElement *element, GstFormat format, gint64 *cur)
' Queries an element for the stream position in nanoseconds.
Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, cur 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 audio As Pointer
Dim pos As Long
gst_init(0, 0)
audio = gst_parse_launch("uridecodebin uri=http://maxxima.mine.nu:8080/maxxima.mp3 ! audioconvert ! audioresample ! jackaudiosink", 0)
' Avvia l'esecuzione audio della radio web:
gst_element_set_state(audio, GST_STATE_PLAYING)
Repeat
gst_element_query_position(audio, GST_FORMAT_TIME, VarPtr(pos))
Write "\rTempo trascorso: " & Str(Time(0, 0, 0, pos / 1000000))
Wait 0.01
Until bo = True
gst_object_unref(audio)
Quit
End
Public Sub Application_Read() ' Premendo il tasto "Invio", si chiuderà il programma
bo = True
End
