GstDeviceProvider

GstDeviceProvider

GObject
    ╰──GInitiallyUnowned
        ╰──GstObject
            ╰──GstDeviceProvider

Since : 1.4

Class structure

gst_device_provider_can_monitor

gboolean
gst_device_provider_can_monitor (GstDeviceProvider * provider)

gst_device_provider_device_add

gst_device_provider_device_add (GstDeviceProvider * provider,
                                GstDevice * device)

Posts a message on the provider's GstBus to inform applications that a new device has been added.

This is for use by subclasses.

device's reference count will be incremented, and any floating reference will be removed (see gst_object_ref_sink).

Since : 1.4

gst_device_provider_device_changed

gst_device_provider_device_changed (GstDeviceProvider * provider,
                                    GstDevice * device,
                                    GstDevice * changed_device)

This function is used when changed_device was modified into its new form device. This will post a DEVICE_CHANGED message on the bus to let the application know that the device was modified. GstDevice is immutable for MT. safety purposes so this is an "atomic" way of letting the application know when a device was modified.

Since : 1.16

gst_device_provider_device_remove

gst_device_provider_device_remove (GstDeviceProvider * provider,
                                   GstDevice * device)

Posts a message on the provider's GstBus to inform applications that a device has been removed.

This is for use by subclasses.

Since : 1.4

gst_device_provider_get_bus

GstBus *
gst_device_provider_get_bus (GstDeviceProvider * provider)

Gets the GstBus of this GstDeviceProvider

Since : 1.4

gst_device_provider_get_devices

GList *
gst_device_provider_get_devices (GstDeviceProvider * provider)

Gets a list of devices that this provider understands. This may actually probe the hardware if the provider is not currently started.

If the provider has been started, this will returned the same GstDevice objedcts that have been returned by the GST_MESSAGE_DEVICE_ADDED messages.

Since : 1.4

gst_device_provider_get_factory

GstDeviceProviderFactory *
gst_device_provider_get_factory (GstDeviceProvider * provider)

Retrieves the factory that was used to create this device provider.

Since : 1.4

gst_device_provider_get_hidden_providers

gchar **
gst_device_provider_get_hidden_providers (GstDeviceProvider * provider)

Get the provider factory names of the GstDeviceProvider instances that are hidden by provider.

Since : 1.6

gst_device_provider_get_metadata

const gchar *
gst_device_provider_get_metadata (GstDeviceProvider * provider,
                                  const gchar * key)

Get metadata with key in provider.

Since : 1.14

gst_device_provider_hide_provider

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

gst_device_provider_is_started

gboolean
gst_device_provider_is_started (GstDeviceProvider * provider)

This function can be used to know if the provider was successfully started.

Since : 1.20

gst_device_provider_start

gboolean
gst_device_provider_start (GstDeviceProvider * provider)

Starts providering the devices. This will cause GST_MESSAGE_DEVICE_ADDED and GST_MESSAGE_DEVICE_REMOVED messages to be posted on the provider's bus when devices are added or removed from the system.

Since the GstDeviceProvider is a singleton, gst_device_provider_start may already have been called by another user of the object, gst_device_provider_stop needs to be called the same number of times.

After this function has been called, gst_device_provider_get_devices will return the same objects that have been received from the GST_MESSAGE_DEVICE_ADDED messages and will no longer probe.

Since : 1.4

gst_device_provider_stop

gst_device_provider_stop (GstDeviceProvider * provider)

Decreases the use-count by one. If the use count reaches zero, this GstDeviceProvider will stop providering the devices. This needs to be called the same number of times that gst_device_provider_start was called.

Since : 1.4

gst_device_provider_unhide_provider

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

gst_device_provider_class_add_metadata

gst_device_provider_class_add_metadata (GstDeviceProviderClass * klass,
                                        const gchar * key,
                                        const gchar * value)

Set key with value as metadata in klass.

Since : 1.4

gst_device_provider_class_add_static_metadata

gst_device_provider_class_add_static_metadata (GstDeviceProviderClass * klass,
                                               const gchar * key,
                                               const gchar * value)

Set key with value as metadata in klass.

Same as gst_device_provider_class_add_metadata, but value must be a static string or an inlined string, as it will not be copied. (GStreamer plugins will be made resident once loaded, so this function can be used even from dynamically loaded plugins.)

Since : 1.4

gst_device_provider_class_get_metadata

const gchar *
gst_device_provider_class_get_metadata (GstDeviceProviderClass * klass,
                                        const gchar * key)

Get metadata with key in klass.

Since : 1.4

gst_device_provider_class_set_metadata

gst_device_provider_class_set_metadata (GstDeviceProviderClass * klass,
                                        const gchar * longname,
                                        const gchar * classification,
                                        const gchar * description,
                                        const gchar * author)

Sets the detailed information for a GstDeviceProviderClass.

This function is for use in _class_init functions only.

Since : 1.4

gst_device_provider_class_set_static_metadata

gst_device_provider_class_set_static_metadata (GstDeviceProviderClass * klass,
                                               const gchar * longname,
                                               const gchar * classification,
                                               const gchar * description,
                                               const gchar * author)

Sets the detailed information for a GstDeviceProviderClass.

This function is for use in _class_init functions only.

Same as gst_device_provider_class_set_metadata, but longname, classification, description, and author must be static strings or inlined strings, as they will not be copied. (GStreamer plugins will be made resident once loaded, so this function can be used even from dynamically loaded plugins.)

Since : 1.4

gst_device_provider_register

gboolean
gst_device_provider_register (GstPlugin * plugin,
                              const gchar * name,
                              guint rank,
                              GType type)

Create a new device providerfactory capable of instantiating objects of the type and add the factory to plugin.

Since : 1.4

provider-hidden

provider_hidden_callback (GstDeviceProvider * self,
                          gchar * object,
                          gpointer user_data)

Flags: Run First

provider-unhidden

provider_unhidden_callback (GstDeviceProvider * self,
                            gchar * object,
                            gpointer user_data)

Flags: Run First

probe

GList *
probe (GstDeviceProvider * provider)

Returns a list of devices that are currently available. This should never block. The devices should not have a parent and should be floating.

start

gboolean
start (GstDeviceProvider * provider)

Starts monitoring for new devices. Only subclasses that can know that devices have been added or remove need to implement this method.

stop

stop (GstDeviceProvider * provider)

Stops monitoring for new devices. Only subclasses that implement the start method need to implement this method.

GST_DEVICE_PROVIDER_CAST

#define GST_DEVICE_PROVIDER_CAST(obj)            ((GstDeviceProvider *)(obj))

GST_DEVICE_PROVIDER_REGISTER

#define GST_DEVICE_PROVIDER_REGISTER(d_p, plugin) G_PASTE(gst_device_provider_register_, d_p) (plugin)

This macro can be used to register a device provider into a GstPlugin. This method will be usually called in the plugin init function but can also be called with a NULL plugin.

Since : 1.20

GST_DEVICE_PROVIDER_REGISTER_DECLARE

#define GST_DEVICE_PROVIDER_REGISTER_DECLARE(d_p) \
G_BEGIN_DECLS \
gboolean G_PASTE(gst_device_provider_register_, d_p) (GstPlugin * plugin); \
G_END_DECLS

This macro can be used to declare a new device provider. It has to be used in combination with GST_DEVICE_PROVIDER_REGISTER_DEFINE macro and must be placed outside any block to declare the device provider registration function.

Since : 1.20

GST_DEVICE_PROVIDER_REGISTER_DEFINE

#define GST_DEVICE_PROVIDER_REGISTER_DEFINE(d_p, d_p_n, r, t) \
G_BEGIN_DECLS \
gboolean G_PASTE (gst_device_provider_register_, d_p) (GstPlugin * plugin) \
{ \
  return gst_device_provider_register (plugin, d_p_n, r, t); \
} \
G_END_DECLS

A convenience macro to define the entry point of a device provider gst_device_provider_register_*(GstPlugin* plugin).

Since : 1.20

GST_DEVICE_PROVIDER_REGISTER_DEFINE_CUSTOM

#define GST_DEVICE_PROVIDER_REGISTER_DEFINE_CUSTOM(d_p, register_func) \
G_BEGIN_DECLS \
gboolean G_PASTE (gst_device_provider_register_, d_p) (GstPlugin * plugin) \
{ \
  return register_func (plugin); \
} \
G_END_DECLS

A convenience macro to define the entry point of a device provider gst_device_provider_register_*(GstPlugin* plugin) which uses register_func as the main registration method for the device provider. As an example, you may define the device provider named "device-provider" with the namespace my as following using device_provider_register_custom:

gboolean my_device_provider_register_custom (GstPlugin * plugin)
{
   gboolean ret = FALSE;
   ret |= gst_device_provider_register (plugin, "my-device-provider",
        GST_RANK_PRIMARY, GST_TYPE_MY_DEVICE_PROVIDER);
   return TRUE;
}

GST_DEVICE_PROVIDER_REGISTER_DEFINE_CUSTOM (my_device_provider, my_device_provider_register_custom)

Since : 1.20