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Applications should create a GstDeviceMonitor when they want to probe, list and monitor devices of a specific type. The GstDeviceMonitor will create the appropriate GstDeviceProvider objects and manage them. It will then post messages on its GstBus for devices that have been added and removed.
The device monitor will monitor all devices matching the filters that the application has set.
The basic use pattern of a device monitor is as follows:
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static gboolean my_bus_func (GstBus * bus, GstMessage * message, gpointer user_data) { GstDevice *device; gchar *name; switch (GST_MESSAGE_TYPE (message)) { case GST_MESSAGE_DEVICE_ADDED: gst_message_parse_device_added (message, &device); name = gst_device_get_display_name (device); g_print("Device added: %s\n", name); g_free (name); break; case GST_MESSAGE_DEVICE_REMOVED: gst_message_parse_device_removed (message, &device); name = gst_device_get_display_name (device); g_print("Device removed: %s\n", name); g_free (name); break; default: break; } return G_SOURCE_CONTINUE; } GstDeviceMonitor * setup_raw_video_source_device_monitor (void) { GstDeviceMonitor *monitor; GstBus *bus; GstCaps *caps; monitor = gst_device_monitor_new (); bus = gst_device_monitor_get_bus (monitor); gst_bus_add_watch (bus, my_bus_func, NULL); gst_object_unref (bus); caps = gst_caps_new_empty_simple ("video/x-raw"); gst_device_monitor_add_filter (monitor, "Video/Source", caps); gst_caps_unref (caps); gst_device_monitor_start (monitor); return monitor; } |
GstDeviceMonitor *
gst_device_monitor_new (void);
Create a new GstDeviceMonitor
Since: 1.4
GstBus *
gst_device_monitor_get_bus (GstDeviceMonitor *monitor);
Gets the GstBus of this GstDeviceMonitor
Since: 1.4
guint gst_device_monitor_add_filter (GstDeviceMonitor *monitor,const gchar *classes,GstCaps *caps);
Adds a filter for which GstDevice will be monitored, any device that matches all these classes and the GstCaps will be returned.
If this function is called multiple times to add more filters, each will be matched independently. That is, adding more filters will not further restrict what devices are matched.
The GstCaps supported by the device as returned by gst_device_get_caps() are
not intersected with caps filters added using this function.
Filters must be added before the GstDeviceMonitor is started.
Since: 1.4
gboolean gst_device_monitor_remove_filter (GstDeviceMonitor *monitor,guint filter_id);
Removes a filter from the GstDeviceMonitor using the id that was returned
by gst_device_monitor_add_filter().
Since: 1.4
gboolean
gst_device_monitor_start (GstDeviceMonitor *monitor);
Starts monitoring the devices, one this has succeeded, the
GST_MESSAGE_DEVICE_ADDED and GST_MESSAGE_DEVICE_REMOVED messages
will be emitted on the bus when the list of devices changes.
Since: 1.4
void
gst_device_monitor_stop (GstDeviceMonitor *monitor);
Stops monitoring the devices.
Since: 1.4
GList *
gst_device_monitor_get_devices (GstDeviceMonitor *monitor);
Gets a list of devices from all of the relevant monitors. This may actually probe the hardware if the monitor is not currently started.
Since: 1.4
gchar **
gst_device_monitor_get_providers (GstDeviceMonitor *monitor);
Get a list of the currently selected device provider factories.
This
A list of device provider factory names that are currently being
monitored by monitor
or NULL when nothing is being monitored.
[transfer full][array zero-terminated=1][element-type gchar*]
Since: 1.6
gboolean
gst_device_monitor_get_show_all_devices
(GstDeviceMonitor *monitor);
Get if monitor
is curretly showing all devices, even those from hidden
providers.
Since: 1.6
void gst_device_monitor_set_show_all_devices (GstDeviceMonitor *monitor,gboolean show_all);
Set if all devices should be visible, even those devices from hidden
providers. Setting show_all
to true might show some devices multiple times.
Since: 1.6
gchar **
gst_device_provider_get_hidden_providers
(GstDeviceProvider *provider);
Get the provider factory names of the GstDeviceProvider instances that
are hidden by provider
.
a list of hidden providers factory names or NULL when
nothing is hidden by provider
. Free with g_strfreev.
[transfer full][array zero-terminated=1][element-type gchar*]
Since: 1.6
void gst_device_provider_hide_provider (GstDeviceProvider *provider,const gchar *name);
Make provider
hide the devices from the factory with name
.
This function is used when provider
will also provide the devices reported
by provider factory name
. A monitor should stop monitoring the
device provider with name
to avoid duplicate devices.
Since: 1.6
void gst_device_provider_unhide_provider (GstDeviceProvider *provider,const gchar *name);
Make provider
unhide the devices from factory name
.
This function is used when provider
will no longer provide the devices
reported by provider factory name
. A monitor should start
monitoring the devices from provider factory name
in order to see
all devices again.
Since: 1.6