gstreamer/gst/gstdeviceprovider.h
Stéphane Cerveau 178c7d2732 device provider: add custom register macro
This macro allows to register a device provider with
a custom function which gives more flexibility when
registering it (see v4l2 register).

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/773>
2021-03-19 10:15:49 +00:00

266 lines
9.9 KiB
C

/* GStreamer
* Copyright (C) 2012 Olivier Crete <olivier.crete@collabora.com>
*
* gstdeviceprovider.h: Device probing and monitoring
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __GST_DEVICE_PROVIDER_H__
#define __GST_DEVICE_PROVIDER_H__
#include <gst/gstelement.h>
/**
* GST_DEVICE_PROVIDER_REGISTER_DEFINE_CUSTOM:
* @d_p: The device provider name in lower case, with words separated by '_'.
* Used to generate `gst_device_provider_register_*(GstPlugin* plugin)`.
* @register_func: pointer to a method with the format: `gboolean register_func (GstPlugin* plugin);`
*
* 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
*/
#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
/**
* GST_DEVICE_PROVIDER_REGISTER_DEFINE:
* @d_p: The device provider name in lower case, with words separated by '_'.
* Used to generate `gst_device_provider_register_*(GstPlugin* plugin)`.
* @d_p_n: The public name of the device provider
* @r: The #GstRank of the device provider (higher rank means more importance when autoplugging, see #GstRank)
* @t: The #GType of the device provider.
*
* A convenience macro to define the entry point of a
* device provider `gst_device_provider_register_*(GstPlugin* plugin)`.
*
* Since: 1.20
*/
#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
/**
* GST_DEVICE_PROVIDER_REGISTER_DECLARE:
* @d_p: The device provider name in lower case, with words separated by '_'.
*
* 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
*/
#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
/**
* GST_DEVICE_PROVIDER_REGISTER:
* @d_p: The device provider name in lower case, with words separated by '_'.
* @plugin: The #GstPlugin where to register the device provider.
*
* 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
*/
#define GST_DEVICE_PROVIDER_REGISTER(d_p, plugin) G_PASTE(gst_device_provider_register_, d_p) (plugin)
G_BEGIN_DECLS
typedef struct _GstDeviceProvider GstDeviceProvider;
typedef struct _GstDeviceProviderClass GstDeviceProviderClass;
typedef struct _GstDeviceProviderPrivate GstDeviceProviderPrivate;
#include <gst/gstdeviceproviderfactory.h>
#define GST_TYPE_DEVICE_PROVIDER (gst_device_provider_get_type())
#define GST_IS_DEVICE_PROVIDER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_DEVICE_PROVIDER))
#define GST_IS_DEVICE_PROVIDER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_DEVICE_PROVIDER))
#define GST_DEVICE_PROVIDER_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_DEVICE_PROVIDER, GstDeviceProviderClass))
#define GST_DEVICE_PROVIDER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_DEVICE_PROVIDER, GstDeviceProvider))
#define GST_DEVICE_PROVIDER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_DEVICE_PROVIDER, GstDeviceProviderClass))
#define GST_DEVICE_PROVIDER_CAST(obj) ((GstDeviceProvider *)(obj))
/**
* GstDeviceProvider:
* @parent: The parent #GstObject
* @devices: a #GList of the #GstDevice objects
*
* The structure of the base #GstDeviceProvider
*
* Since: 1.4
*/
struct _GstDeviceProvider {
GstObject parent;
/* Protected by the Object lock */
GList *devices;
/*< private >*/
GstDeviceProviderPrivate *priv;
gpointer _gst_reserved[GST_PADDING];
};
/**
* GstDeviceProviderClass:
* @parent_class: the parent #GstObjectClass structure
* @factory: a pointer to the #GstDeviceProviderFactory that creates this
* provider
* @probe: 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: Starts monitoring for new devices. Only subclasses that can know
* that devices have been added or remove need to implement this method.
* @stop: Stops monitoring for new devices. Only subclasses that implement
* the start() method need to implement this method.
*
* The structure of the base #GstDeviceProviderClass
*
* Since: 1.4
*/
struct _GstDeviceProviderClass {
GstObjectClass parent_class;
GstDeviceProviderFactory *factory;
GList* (*probe) (GstDeviceProvider * provider);
gboolean (*start) (GstDeviceProvider * provider);
void (*stop) (GstDeviceProvider * provider);
/*< private >*/
gpointer metadata;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GST_API
GType gst_device_provider_get_type (void);
GST_API
GList * gst_device_provider_get_devices (GstDeviceProvider * provider);
GST_API
gboolean gst_device_provider_start (GstDeviceProvider * provider);
GST_API
void gst_device_provider_stop (GstDeviceProvider * provider);
GST_API
gboolean gst_device_provider_can_monitor (GstDeviceProvider * provider);
GST_API
GstBus * gst_device_provider_get_bus (GstDeviceProvider * provider);
GST_API
void gst_device_provider_device_add (GstDeviceProvider * provider,
GstDevice * device);
GST_API
void gst_device_provider_device_remove (GstDeviceProvider * provider,
GstDevice * device);
GST_API
gchar ** gst_device_provider_get_hidden_providers (GstDeviceProvider * provider);
GST_API
void gst_device_provider_hide_provider (GstDeviceProvider * provider,
const gchar * name);
GST_API
void gst_device_provider_unhide_provider (GstDeviceProvider * provider,
const gchar * name);
GST_API
const gchar * gst_device_provider_get_metadata (GstDeviceProvider * provider,
const gchar * key);
GST_API
gboolean gst_device_provider_is_started (GstDeviceProvider * provider);
/* device provider class meta data */
GST_API
void gst_device_provider_class_set_metadata (GstDeviceProviderClass *klass,
const gchar *longname,
const gchar *classification,
const gchar *description,
const gchar *author);
GST_API
void gst_device_provider_class_set_static_metadata (GstDeviceProviderClass *klass,
const gchar *longname,
const gchar *classification,
const gchar *description,
const gchar *author);
GST_API
void gst_device_provider_class_add_metadata (GstDeviceProviderClass * klass,
const gchar * key, const gchar * value);
GST_API
void gst_device_provider_class_add_static_metadata (GstDeviceProviderClass * klass,
const gchar * key, const gchar * value);
GST_API
const gchar * gst_device_provider_class_get_metadata (GstDeviceProviderClass * klass,
const gchar * key);
GST_API
void gst_device_provider_device_changed (GstDeviceProvider * provider,
GstDevice *device,
GstDevice *changed_device);
/* factory management */
GST_API
GstDeviceProviderFactory * gst_device_provider_get_factory (GstDeviceProvider * provider);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstDeviceProvider, gst_object_unref)
G_END_DECLS
#endif /* __GST_DEVICE_PROVIDER_H__ */