Differenze tra le versioni di "Visualizzare un oscilloscopio di GStreamer mediante la funzione 'gst parse launch()' durante l'esecuzione di un file Midi"
(11 versioni intermedie di uno stesso utente non sono mostrate) | |||
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− | La funzione esterna | + | La funzione esterna "gst_parse_launch()" della libreria ''GStreamer'' consente di costruire e gestire in modo semplice una pipeline ''GStreamer''. La riga della pipeline gestita dalla funzione esterna "gst_parse_launch()" è un insieme di elementi separati da punti esclamativi (!). Le proprietà possono essere aggiunte agli elementi, sotto forma di: ''proprietà = valore''. |
− | Sarà necessario avere installata nel sistema e richiamare nell'applicazione Gambas la libreria | + | Sarà necessario avere installata nel sistema e richiamare nell'applicazione Gambas la libreria condivisa: "''libgstreamer-1.0.so.0.2403.0'' ". |
− | Usando i plugin "''wavescope''" o "''monoscope''" unitamente a "''autoaudiosink''" all'interno della riga della ''pipeline'' della funzione | + | Usando i plugin "''wavescope''" o "''monoscope''" unitamente a "''autoaudiosink''" all'interno della riga della ''pipeline'' della funzione "gst_parse_launch()", è possibile scegliere la visualizzazione di due tipi diversi di oscilloscopio attivo durante l'esecuzione di un file Midi. |
==Uso del plugin ''wavescope''== | ==Uso del plugin ''wavescope''== | ||
Mostriamo un esempio pratico usando i plugin "''wavescope''" e "''autoaudiosink''" all'interno della riga della ''pipeline'' della funzione ''gst_parse_launch()'': | Mostriamo un esempio pratico usando i plugin "''wavescope''" e "''autoaudiosink''" all'interno della riga della ''pipeline'' della funzione ''gst_parse_launch()'': | ||
− | + | Library "libgstreamer-1.0:0.2403.0" | |
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− | 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 | ||
Riga 31: | Riga 28: | ||
' ''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 | + | <FONT color=gray>' ''gboolean gst_element_query_position (GstElement *element, GstFormat format, gint64 *duration)'' |
− | ' ''Queries an element | + | ' ''Queries an element for the total stream position in nanoseconds.''</font> |
− | Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, | + | Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, position As Pointer) As Boolean |
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<FONT Color=gray>' ''void gst_object_unref(gpointer object)'' | <FONT Color=gray>' ''void gst_object_unref(gpointer object)'' | ||
' ''Decrements the reference count on object.''</font> | ' ''Decrements the reference count on object.''</font> | ||
Riga 41: | Riga 38: | ||
− | + | Public Sub Main() | |
− | Dim | + | Dim midi As Pointer |
− | Dim | + | Dim volume As Float |
+ | Dim durata, l As Long | ||
+ | Dim tm As Date | ||
− | + | gst_init(0, 0) | |
− | + | midi = gst_parse_launch("filesrc location=<FONT Color=darkgreen>''/percorso/del/file.mid''</font> ! midiparse ! fluiddec ! tee name=t " & | |
− | + | "! queue ! audioconvert ! wavescope style=3 ! video/x-raw, width=1000 ! videoconvert ! ximagesink t. " & | |
− | + | "! queue ! audioconvert ! m. t. ! queue ! volume volume=7.0 ! autoaudiosink", 0) | |
<FONT Color=gray>' ''Avviamo l'esecuzione del file midi:''</font> | <FONT Color=gray>' ''Avviamo l'esecuzione del file midi:''</font> | ||
− | + | gst_element_set_state(midi, GST_STATE_PLAYING) | |
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− | + | Repeat | |
− | + | gst_element_query_duration(midi, GST_FORMAT_TIME, VarPtr(durata)) | |
− | + | Wait 0.01 | |
− | + | Until durata > -1 | |
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+ | 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 "\nEsecuzione terminata." | |
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− | + | End | |
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==Uso del plugin ''monoscope''== | ==Uso del plugin ''monoscope''== | ||
Mostriamo un esempio pratico usando i plugin "''monoscope''" e "''autoaudiosink''" all'interno della riga della ''pipeline'' della funzione ''gst_parse_launch()'': | Mostriamo un esempio pratico usando i plugin "''monoscope''" e "''autoaudiosink''" all'interno della riga della ''pipeline'' della funzione ''gst_parse_launch()'': | ||
− | + | Library "libgstreamer-1.0:0.2403.0" | |
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− | 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 | ||
Riga 126: | Riga 95: | ||
' ''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 | ||
− | + | ||
− | <FONT | + | <FONT color=gray>' ''gboolean gst_element_query_position (GstElement *element, GstFormat format, gint64 *duration)'' |
− | ' ''Queries an element | + | ' ''Queries an element for the total stream position in nanoseconds.''</font> |
− | Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, | + | Private Extern gst_element_query_position(gstelement As Pointer, gstformat As Pointer, position As Pointer) As Boolean |
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<FONT Color=gray>' ''void gst_object_unref(gpointer object)'' | <FONT Color=gray>' ''void gst_object_unref(gpointer object)'' | ||
' ''Decrements the reference count on object.''</font> | ' ''Decrements the reference count on object.''</font> | ||
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− | + | Public Sub Main() | |
− | Dim | + | Dim midi As Pointer |
− | Dim | + | Dim volume As Float |
− | + | Dim durata, l As Long | |
− | + | Dim tm As Date | |
+ | |||
+ | gst_init(0, 0) | ||
− | + | midi = gst_parse_launch("filesrc location=<FONT Color=darkgreen>''/percorso/del/file.mid''</font> ! midiparse ! fluiddec ! " & | |
− | + | "tee name=t ! queue ! audioconvert ! monoscope ! ximagesink ! queue ! m. t. ! " & | |
+ | "queue ! volume volume=7.0 ! autoaudiosink", 0) | ||
<FONT Color=gray>' ''Avviamo l'esecuzione del file Midi:''</font> | <FONT Color=gray>' ''Avviamo l'esecuzione del file Midi:''</font> | ||
− | + | gst_element_set_state(midi, GST_STATE_PLAYING) | |
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− | + | 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 "\nEsecuzione terminata." | |
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− | + | End | |
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Versione delle 16:24, 4 lug 2024
La funzione esterna "gst_parse_launch()" della libreria GStreamer consente di costruire e gestire in modo semplice una pipeline GStreamer. La riga della pipeline gestita dalla funzione esterna "gst_parse_launch()" è un insieme di elementi separati da punti esclamativi (!). Le proprietà possono essere aggiunte agli elementi, sotto forma di: proprietà = valore.
Sarà necessario avere installata nel sistema e richiamare nell'applicazione Gambas la libreria condivisa: "libgstreamer-1.0.so.0.2403.0 ".
Usando i plugin "wavescope" o "monoscope" unitamente a "autoaudiosink" all'interno della riga della pipeline della funzione "gst_parse_launch()", è possibile scegliere la visualizzazione di due tipi diversi di oscilloscopio attivo durante l'esecuzione di un file Midi.
Uso del plugin wavescope
Mostriamo un esempio pratico usando i plugin "wavescope" e "autoaudiosink" all'interno della riga della pipeline della funzione gst_parse_launch():
Library "libgstreamer-1.0:0.2403.0" 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 ! midiparse ! fluiddec ! tee name=t " & "! queue ! audioconvert ! wavescope style=3 ! video/x-raw, width=1000 ! videoconvert ! ximagesink t. " & "! queue ! audioconvert ! m. t. ! queue ! volume volume=7.0 ! autoaudiosink", 0) ' Avviamo l'esecuzione del file midi: 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 "\nEsecuzione terminata." End
Uso del plugin monoscope
Mostriamo un esempio pratico usando i plugin "monoscope" e "autoaudiosink" all'interno della riga della pipeline della funzione gst_parse_launch():
Library "libgstreamer-1.0:0.2403.0" 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 ! midiparse ! fluiddec ! " & "tee name=t ! queue ! audioconvert ! monoscope ! ximagesink ! queue ! m. t. ! " & "queue ! volume volume=7.0 ! autoaudiosink", 0) ' Avviamo l'esecuzione del file Midi: 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 "\nEsecuzione terminata." End
Riferimenti
- http://docs.gstreamer.com/display/GstSDK/gst-launch
- https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-bad-plugins/html/gst-plugins-bad-plugins-wavescope.html
- https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-monoscope.html
- http://gstreamer.freedesktop.org/
- http://gstreamer.com/