`GObject
|
+GstObject
| |
| +GstPad
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| +GstPadTemplate
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| +GstPluginFeature
| | |
| | +GstElementFactory
| | |
| | +GstTypeFindFactory
| | |
| | `GstIndexFactory
| |
| +GstElement
| | |
| | `GstBin
| | |
| | `GstPipeline
| |
| +GstBus
| |
| +GstTask
| |
| +GstTaskPool
| |
| +GstClock
| |
| +GstPlugin
| |
| `GstRegistry
|
`GstSignalObject
|
`GstMiniObject
|
+GstQuery
|
+GstMessage
|
+GstBuffer
|
+GstEvent
|
`GstBufferList
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/**
* GstObject:
* @refcount: unused
* @lock: object LOCK
* @name: The name of the object
* @name_prefix: unused
* @parent: this object's parent, weak ref
* @flags: use GST_OBJECT_IS_XXX macros to access the flags
*
* GStreamer base object class.
*/
struct _GstObject {
GObject object;
/*< public >*/
gint refcount; /* unused (FIXME 0.11: remove) */
/*< public >*/ /* with LOCK */
GMutex *lock; /* object LOCK */
gchar *name; /* object name */
gchar *name_prefix; /* (un)used for debugging (FIXME 0.11: remove) */
GstObject *parent; /* this object's parent, weak ref */
guint32 flags;
/*< private >*/
gpointer _gst_reserved;
};
/**
* GstObjectClass:
* @parent_class: parent
* @path_string_separator: separator used by gst_object_get_path_string()
* @signal_object: is used to signal to the whole class
* @lock: class lock to be used with GST_CLASS_GET_LOCK(), GST_CLASS_LOCK(), GST_CLASS_UNLOCK() and others.
* @parent_set: default signal handler
* @parent_unset: default signal handler
* @object_saved: default signal handler
* @deep_notify: default signal handler
* @save_thyself: xml serialisation
* @restore_thyself: xml de-serialisation
*
* GStreamer base object class.
*/
struct _GstObjectClass {
GObjectClass parent_class;
const gchar *path_string_separator;
GObject *signal_object;
/* FIXME-0.11: remove this, plus the above GST_CLASS_*_LOCK macros */
GStaticRecMutex *lock;
/* signals */
/* FIXME-0.11: remove, and pass NULL in g_signal_new(), we never used them */
void (*parent_set) (GstObject * object, GstObject * parent);
void (*parent_unset) (GstObject * object, GstObject * parent);
/* FIXME 0.11: Remove this, it's deprecated */
void (*object_saved) (GstObject * object, GstXmlNodePtr parent);
void (*deep_notify) (GstObject * object, GstObject * orig, GParamSpec * pspec);
/*< public >*/
/* virtual methods for subclasses */
/* FIXME 0.11: Remove this, it's deprecated */
GstXmlNodePtr (*save_thyself) (GstObject * object, GstXmlNodePtr parent);
void (*restore_thyself) (GstObject * object, GstXmlNodePtr self);
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GObjectGstObject
成員函數 class->constructor = g_object_constructor;
class->constructed = g_object_constructed;
class->set_property = g_object_do_set_property;
class->get_property = g_object_do_get_property;
class->dispose = g_object_real_dispose;
class->finalize = g_object_finalize;
class->dispatch_properties_changed = g_object_dispatch_properties_changed;
class->notify = NULL;override Gobject的一些：
gobject_class->set_property = gst_object_set_property;
gobject_class->get_property = gst_object_get_property;
gobject_class->dispatch_properties_changed
= GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
gobject_class->dispose = gst_object_dispose;
gobject_class->finalize = gst_object_finalize;
Property-"name"
Signals"notify" ; default handler: class->notify = NULL;"parent-set"，it's default handler is NULL?
"parent-unset"，it's default handler is NULL?
"object-saved"，it's default handler is NULL?
"deep-notify"，it's default handler is NULL?
User register signal handler user可以自己注冊"notify"的回調: user handleruser可以自己注冊上面幾個(gè)信號的回調: user handler
何時(shí)emit signal?user 調用GObject的APIs:
g_object_set()
g_object_notify()
g_object_notify_by_pspec()
user 調用GstObject的APIs:
gst_object_set_parent（）
gst_object_unparent（）
gst_object_save_thyself()
Quark data"GObject-closure-array"
"GObject-weak-references"
"GObject-toggle-references"
"GObject-notify-queue"
以及用戶(hù)自定義的
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/**
* GstPad:
* @element_private: private data owned by the parent element
* @padtemplate: padtemplate for this pad
* @direction: the direction of the pad, cannot change after creating
* the pad.
* @stream_rec_lock: recursive stream lock of the pad, used to protect
* the data used in streaming.
* @task: task for this pad if the pad is actively driving dataflow.
* @preroll_lock: lock used when prerolling
* @preroll_cond: conf to signal preroll
* @block_cond: conditional to signal pad block
* @block_callback: callback for the pad block if any
* @block_data: user data for @block_callback
* @caps: the current caps of the pad
* @getcapsfunc: function to get caps of the pad
* @setcapsfunc: function to set caps on the pad
* @acceptcapsfunc: function to check if pad can accept caps
* @fixatecapsfunc: function to fixate caps
* @activatefunc: pad activation function
* @activatepushfunc: function to activate/deactivate pad in push mode
* @activatepullfunc: function to activate/deactivate pad in pull mode
* @linkfunc: function called when pad is linked
* @unlinkfunc: function called when pad is unlinked
* @peer: the pad this pad is linked to
* @sched_private: private storage for the scheduler
* @chainfunc: function to chain buffer to pad
* @checkgetrangefunc: function to check if pad can operate in pull mode
* @getrangefunc: function to get a range of data from a pad
* @eventfunc: function to send an event to a pad
* @mode: current activation mode of the pad
* @querytypefunc: get list of supported queries
* @queryfunc: perform a query on the pad
* @intlinkfunc: get the internal links of this pad
* @bufferallocfunc: function to allocate a buffer for this pad
* @do_buffer_signals: counter counting installed buffer signals
* @do_event_signals: counter counting installed event signals
* @iterintlinkfunc: get the internal links iterator of this pad
* @block_destroy_data: notify function for gst_pad_set_blocked_async_full()
*
* The #GstPad structure. Use the functions to update the variables.
*/
struct _GstPad {
GstObject object;
/*< public >*/
gpointer element_private;
GstPadTemplate *padtemplate;
GstPadDirection direction;
/*< public >*/ /* with STREAM_LOCK */
/* streaming rec_lock */
GStaticRecMutex *stream_rec_lock;
GstTask *task;
/*< public >*/ /* with PREROLL_LOCK */
GMutex *preroll_lock;
GCond *preroll_cond;
/*< public >*/ /* with LOCK */
/* block cond, mutex is from the object */
GCond *block_cond;
GstPadBlockCallback block_callback;
gpointer block_data;
/* the pad capabilities */
GstCaps *caps;
GstPadGetCapsFunction getcapsfunc;
GstPadSetCapsFunction setcapsfunc;
GstPadAcceptCapsFunction acceptcapsfunc;
GstPadFixateCapsFunction fixatecapsfunc;
GstPadActivateFunction activatefunc;
GstPadActivateModeFunction activatepushfunc;
GstPadActivateModeFunction activatepullfunc;
/* pad link */
GstPadLinkFunction linkfunc;
GstPadUnlinkFunction unlinkfunc;
GstPad *peer;
gpointer sched_private;
/* data transport functions */
GstPadChainFunction chainfunc;
GstPadCheckGetRangeFunction checkgetrangefunc;
GstPadGetRangeFunction getrangefunc;
GstPadEventFunction eventfunc;
GstActivateMode mode;
/* generic query method */
GstPadQueryTypeFunction querytypefunc;
GstPadQueryFunction queryfunc;
/* internal links */
#ifndef GST_DISABLE_DEPRECATED
GstPadIntLinkFunction intlinkfunc;
#else
#ifndef __GTK_DOC_IGNORE__
gpointer intlinkfunc;
#endif
#endif
GstPadBufferAllocFunction bufferallocfunc;
/* whether to emit signals for have-data. counts number
* of handlers attached. */
gint do_buffer_signals;
gint do_event_signals;
/* ABI added */
/* iterate internal links */
GstPadIterIntLinkFunction iterintlinkfunc;
/* free block_data */
GDestroyNotify block_destroy_data;
/*< private >*/
union {
struct {
gboolean block_callback_called;
GstPadPrivate *priv;
} ABI;
gpointer _gst_reserved[GST_PADDING - 2];
} abidata;
};
struct _GstPadClass {
GstObjectClass parent_class;
/* signal callbacks */
void (*linked) (GstPad *pad, GstPad *peer);
void (*unlinked) (GstPad *pad, GstPad *peer);
void (*request_link) (GstPad *pad);
gboolean (*have_data) (GstPad *pad, GstMiniObject *data);
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GObjectGstObjectGstPad
成員函數 override Gobject的一些：
gobject_class->set_property = gst_object_set_property;
gobject_class->get_property = gst_object_get_property;
gobject_class->dispatch_properties_changed
= GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
gobject_class->dispose = gst_object_dispose;
gobject_class->finalize = gst_object_finalize;
gobject_class->dispose = gst_pad_dispose;
gobject_class->finalize = gst_pad_finalize;
gobject_class->set_property = gst_pad_set_property;
gobject_class->get_property = gst_pad_get_property;
Property-"name""caps"
"direction"
"template"
enum
{
PAD_PROP_0,
PAD_PROP_CAPS,
PAD_PROP_DIRECTION,
PAD_PROP_TEMPLATE,
/* FILL ME */
};
Signals "parent-set"，it's default handler is NULL?
"parent-unset"，it's default handler is NULL?
"object-saved"，it's default handler is NULL?
"deep-notify"，it's default handler is NULL?
"linked"
"unlinked"
"request-link"
"have-data"
enum
{
PAD_LINKED,
PAD_UNLINKED,
PAD_REQUEST_LINK,
PAD_HAVE_DATA,
/* FILL ME */
LAST_SIGNAL
};
User register signal handler user可以自己注冊上面幾個(gè)信號的回調: user handler
何時(shí)emit signal?
user 調用GstObject的APIs:
gst_object_set_parent（）
gst_object_unparent（）
gst_object_save_thyself()
gst_pad_signals[PAD_LINKED]:
1. gst_pad_link_full()
2. gst_pad_link()
gst_pad_signals[PAD_UNLINKED]:
1. gst_pad_unlink()
gst_pad_signals[PAD_HAVE_DATA]:
1. gst_pad_pull_range()
2. gst_pad_push_event()
3. gst_pad_send_event()
Quark data
/* quarks for probe signals */
static GQuark buffer_quark;
static GQuark event_quark;
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/**
* GstPadTemplate:
*
* The padtemplate object.
*/
struct _GstPadTemplate {
GstObject object;
gchar *name_template;
GstPadDirection direction;
GstPadPresence presence;
GstCaps *caps;
gpointer _gst_reserved[GST_PADDING];
};
struct _GstPadTemplateClass {
GstObjectClass parent_class;
/* signal callbacks */
void (*pad_created) (GstPadTemplate *templ, GstPad *pad);
gpointer _gst_reserved[GST_PADDING];
};
GObjectGstObjectGstPadTemplate
成員函數 override Gobject的一些：
gobject_class->set_property = gst_object_set_property;
gobject_class->get_property = gst_object_get_property;
gobject_class->dispatch_properties_changed
= GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
gobject_class->dispose = gst_object_dispose;
gobject_class->finalize = gst_object_finalize;
gobject_class->dispose = gst_pad_template_dispose;
gobject_class->get_property = gst_pad_template_get_property;
gobject_class->set_property = gst_pad_template_set_property;
Property-"name"enum
{
PROP_NAME_TEMPLATE = 1,
PROP_DIRECTION,
PROP_PRESENCE,
PROP_CAPS
};
Signals "parent-set"，it's default handler is NULL?
"parent-unset"，it's default handler is NULL?
"object-saved"，it's default handler is NULL?
"deep-notify"，it's default handler is NULL?
"pad-created"
enum
{
TEMPL_PAD_CREATED,
/* FILL ME */
LAST_SIGNAL
};
User register signal handler user可以自己注冊上面幾個(gè)信號的回調: user handler
何時(shí)emit signal?
user 調用GstObject的APIs:
gst_object_set_parent（）
gst_object_unparent（）
gst_object_save_thyself()
gst_pad_template_signals[TEMPL_PAD_CREATED]:
gst_pad_template_pad_created
Quark data
/* quarks for probe signals */
static GQuark buffer_quark;
static GQuark event_quark;
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/**
* GstPluginFeature:
*
* Opaque #GstPluginFeature structure.
*/
struct _GstPluginFeature {
GstObject object;
/*< private >*/
gboolean loaded;
gchar *name; /* FIXME-0.11: remove variable, we use GstObject:name */
guint rank;
const gchar *plugin_name;
GstPlugin *plugin; /* weak ref */
/*< private >*/
gpointer _gst_reserved[GST_PADDING - 1];
};
struct _GstPluginFeatureClass {
GstObjectClass parent_class;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GObjectGstObjectGstPluginFeature
成員函數 override Gobject的一些：
gobject_class->set_property = gst_object_set_property;
gobject_class->get_property = gst_object_get_property;
gobject_class->dispatch_properties_changed
= GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
gobject_class->dispose = gst_object_dispose;
gobject_class->finalize = gst_object_finalize;
G_OBJECT_CLASS (klass)->finalize = gst_plugin_feature_finalize;
Property-"name"
Signals "parent-set"，it's default handler is NULL?
"parent-unset"，it's default handler is NULL?
"object-saved"，it's default handler is NULL?
"deep-notify"，it's default handler is NULL?
User register signal handler user可以自己注冊上面幾個(gè)信號的回調: user handler
何時(shí)emit signal?
user 調用GstObject的APIs:
gst_object_set_parent（）
gst_object_unparent（）
gst_object_save_thyself()
Quark data
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/**
* GstElementFactory:
*
* The opaque #GstElementFactory data structure.
*/
struct _GstElementFactory {
GstPluginFeature parent;
GType type; /* unique GType of element or 0 if not loaded */
/* FIXME-0.11: deprecate this in favour of meta_data */
GstElementDetails details;
GList * staticpadtemplates; /* GstStaticPadTemplate list */
guint numpadtemplates;
/* URI interface stuff */
guint uri_type;
gchar ** uri_protocols;
GList * interfaces; /* interface type names this element implements */
/*< private >*/
/* FIXME-0.11: move up and replace details */
gpointer meta_data;
gpointer _gst_reserved[GST_PADDING - 1];
};
struct _GstElementFactoryClass {
GstPluginFeatureClass parent_class;
gpointer _gst_reserved[GST_PADDING];
};
GObjectGstObjectGstPluginFeatureGstElementFactory
成員函數
G_OBJECT_CLASS (klass)->finalize = gst_plugin_feature_finalize;
gobject_class->finalize = gst_element_factory_finalize;
Property
Signals
User register signal handler
何時(shí)emit signal?
Quark data
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/**
* GstTypeFindFactory:
*
* Object that stores information about a typefind function.
*/
struct _GstTypeFindFactory {
GstPluginFeature feature;
/* <private> */
GstTypeFindFunction function;
gchar ** extensions;
GstCaps * caps; /* FIXME: not yet saved in registry */
gpointer user_data;
GDestroyNotify user_data_notify;
gpointer _gst_reserved[GST_PADDING];
};
struct _GstTypeFindFactoryClass {
GstPluginFeatureClass parent;
/* <private> */
gpointer _gst_reserved[GST_PADDING];
};
GObjectGstObjectGstPluginFeatureGstTypeFindFactory
成員函數
G_OBJECT_CLASS (klass)->finalize = gst_plugin_feature_finalize;
object_class->dispose = gst_type_find_factory_dispose;
Property
Signals
User register signal handler
何時(shí)emit signal?
Quark data
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/**
* GstIndexFactory:
*
* The GstIndexFactory object
*/
struct _GstIndexFactory {
GstPluginFeature feature;
gchar *longdesc; /* long description of the index (well, don't overdo it..) */
GType type; /* unique GType of the index */
gpointer _gst_reserved[GST_PADDING];
};
struct _GstIndexFactoryClass {
GstPluginFeatureClass parent;
gpointer _gst_reserved[GST_PADDING];
};
GObjectGstObjectGstPluginFeatureGstIndexFactory
成員函數
G_OBJECT_CLASS (klass)->finalize = gst_plugin_feature_finalize;
gobject_class->finalize = gst_index_factory_finalize;
Property
Signals
User register signal handler
何時(shí)emit signal?
Quark data
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/**
* GstElement:
* @state_lock: Used to serialize execution of gst_element_set_state()
* @state_cond: Used to signal completion of a state change
* @state_cookie: Used to detect concurrent execution of
* gst_element_set_state() and gst_element_get_state()
* @current_state: the current state of an element
* @next_state: the next state of an element, can be #GST_STATE_VOID_PENDING if
* the element is in the correct state.
* @pending_state: the final state the element should go to, can be
* #GST_STATE_VOID_PENDING if the element is in the correct state
* @last_return: the last return value of an element state change
* @bus: the bus of the element. This bus is provided to the element by the
* parent element or the application. A #GstPipeline has a bus of its own.
* @clock: the clock of the element. This clock is usually provided to the
* element by the toplevel #GstPipeline.
* @base_time: the time of the clock right before the element is set to
* PLAYING. Subtracting @base_time from the current clock time in the PLAYING
* state will yield the running_time against the clock.
* @numpads: number of pads of the element, includes both source and sink pads.
* @pads: list of pads
* @numsrcpads: number of source pads of the element.
* @srcpads: list of source pads
* @numsinkpads: number of sink pads of the element.
* @sinkpads: list of sink pads
* @pads_cookie: updated whenever the a pad is added or removed
*
* GStreamer element abstract base class.
*/
struct _GstElement
{
GstObject object;
/*< public >*/ /* with LOCK */
GStaticRecMutex *state_lock;
/* element state */
GCond *state_cond;
guint32 state_cookie;
GstState current_state;
GstState next_state;
GstState pending_state;
GstStateChangeReturn last_return;
GstBus *bus;
/* allocated clock */
GstClock *clock;
GstClockTimeDiff base_time; /* NULL/READY: 0 - PAUSED: current time - PLAYING: difference to clock */
/* element pads, these lists can only be iterated while holding
* the LOCK or checking the cookie after each LOCK. */
guint16 numpads;
GList *pads;
guint16 numsrcpads;
GList *srcpads;
guint16 numsinkpads;
GList *sinkpads;
guint32 pads_cookie;
/*< private >*/
union {
struct {
/* state set by application */
GstState target_state;
/* running time of the last PAUSED state */
GstClockTime start_time;
} ABI;
/* adding + 0 to mark ABI change to be undone later */
gpointer _gst_reserved[GST_PADDING + 0];
} abidata;
};
/**
* GstElementClass:
* @parent_class: the parent class structure
* @details: #GstElementDetails for elements of this class
* @elementfactory: the #GstElementFactory that creates these elements
* @padtemplates: a #GList of #GstPadTemplate
* @numpadtemplates: the number of padtemplates
* @pad_templ_cookie: changed whenever the padtemplates change
* @request_new_pad: called when a new pad is requested
* @release_pad: called when a request pad is to be released
* @get_state: get the state of the element
* @set_state: set a new state on the element
* @change_state: called by @set_state to perform an incremental state change
* @set_bus: set a #GstBus on the element
* @provide_clock: gets the #GstClock provided by the element
* @set_clock: set the #GstClock on the element
* @get_index: set a #GstIndex on the element
* @set_index: get the #GstIndex of an element
* @send_event: send a #GstEvent to the element
* @get_query_types: get the supported #GstQueryType of this element
* @query: perform a #GstQuery on the element
* @request_new_pad_full: called when a new pad is requested. Since: 0.10.32.
* @state_changed: called immediately after a new state was set. Since: 0.10.36.
*
* GStreamer element class. Override the vmethods to implement the element
* functionality.
*/
struct _GstElementClass
{
GstObjectClass parent_class;
/*< public >*/
/* the element details */
/* FIXME-0.11: deprecate this in favour of meta_data */
GstElementDetails details;
/* factory that the element was created from */
GstElementFactory *elementfactory;
/* templates for our pads */
GList *padtemplates;
gint numpadtemplates;
guint32 pad_templ_cookie;
/*< private >*/
/* signal callbacks */
void (*pad_added) (GstElement *element, GstPad *pad);
void (*pad_removed) (GstElement *element, GstPad *pad);
void (*no_more_pads) (GstElement *element);
/*< public >*/
/* virtual methods for subclasses */
/* request/release pads */
GstPad* (*request_new_pad) (GstElement *element, GstPadTemplate *templ, const gchar* name);
void (*release_pad) (GstElement *element, GstPad *pad);
/* state changes */
GstStateChangeReturn (*get_state) (GstElement * element, GstState * state,
GstState * pending, GstClockTime timeout);
GstStateChangeReturn (*set_state) (GstElement *element, GstState state);
GstStateChangeReturn (*change_state) (GstElement *element, GstStateChange transition);
/* bus */
void (*set_bus) (GstElement * element, GstBus * bus);
/* set/get clocks */
GstClock* (*provide_clock) (GstElement *element);
gboolean (*set_clock) (GstElement *element, GstClock *clock);
/* index */
GstIndex* (*get_index) (GstElement *element);
void (*set_index) (GstElement *element, GstIndex *index);
/* query functions */
gboolean (*send_event) (GstElement *element, GstEvent *event);
const GstQueryType* (*get_query_types) (GstElement *element);
gboolean (*query) (GstElement *element, GstQuery *query);
/*< private >*/
/* FIXME-0.11: move up and replace details */
gpointer meta_data;
/*< public >*/
/* Virtual method for subclasses (additions) */
/* FIXME-0.11 Make this the default behaviour */
GstPad* (*request_new_pad_full) (GstElement *element, GstPadTemplate *templ,
const gchar* name, const GstCaps *caps);
void (*state_changed) (GstElement *element, GstState oldstate,
GstState newstate, GstState pending);
/*< private >*/
gpointer _gst_reserved[GST_PADDING-3];
};
GObjectGstObjectGstElement
成員函數 override Gobject的一些：
gobject_class->set_property = gst_object_set_property;
gobject_class->get_property = gst_object_get_property;
gobject_class->dispatch_properties_changed
= GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
gobject_class->dispose = gst_object_dispose;
gobject_class->finalize = gst_object_finalize;
gobject_class->dispose = gst_element_dispose;
gobject_class->finalize = gst_element_finalize;
Property-"name"
Signals "parent-set"，it's default handler is NULL?
"parent-unset"，it's default handler is NULL?
"object-saved"，it's default handler is NULL?
"deep-notify"，it's default handler is NULL?
enum
{
PAD_ADDED,
PAD_REMOVED,
NO_MORE_PADS,
/* add more above */
LAST_SIGNAL
};
User register signal handler user可以自己注冊上面幾個(gè)信號的回調: user handler
何時(shí)emit signal?
user 調用GstObject的APIs:
gst_object_set_parent（）
gst_object_unparent（）
gst_object_save_thyself()
gst_element_add_pad ()
gst_element_remove_pad()
gst_element_no_more_pads()
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/**
* GstBin:
* @numchildren: the number of children in this bin
* @children: the list of children in this bin
* @children_cookie: updated whenever @children changes
* @child_bus: internal bus for handling child messages
* @messages: queued and cached messages
* @polling: the bin is currently calculating its state
* @state_dirty: the bin needs to recalculate its state (deprecated)
* @clock_dirty: the bin needs to select a new clock
* @provided_clock: the last clock selected
* @clock_provider: the element that provided @provided_clock
*
* The GstBin base class. Subclasses can access these fields provided
* the LOCK is taken.
*/
struct _GstBin {
GstElement element;
/*< public >*/ /* with LOCK */
/* our children, subclass are supposed to update these
* fields to reflect their state with _iterate_*() */
gint numchildren;
GList *children;
guint32 children_cookie;
GstBus *child_bus;
GList *messages;
gboolean polling;
gboolean state_dirty;
gboolean clock_dirty;
GstClock *provided_clock;
GstElement *clock_provider;
/*< private >*/
GstBinPrivate *priv;
gpointer _gst_reserved[GST_PADDING - 1];
};
/**
* GstBinClass:
* @parent_class: bin parent class
* @add_element: method to add an element to a bin
* @remove_element: method to remove an element from a bin
* @handle_message: method to handle a message from the children
*
* Subclasses can override the @add_element and @remove_element to
* update the list of children in the bin.
*
* The @handle_message method can be overridden to implement custom
* message handling. @handle_message takes ownership of the message, just like
* #gst_element_post_message.
*/
struct _GstBinClass {
GstElementClass parent_class;
/*< private >*/
GThreadPool *pool;
/* signals */
void (*element_added) (GstBin *bin, GstElement *child);
void (*element_removed) (GstBin *bin, GstElement *child);
/*< public >*/
/* virtual methods for subclasses */
gboolean (*add_element) (GstBin *bin, GstElement *element);
gboolean (*remove_element) (GstBin *bin, GstElement *element);
void (*handle_message) (GstBin *bin, GstMessage *message);
/*< private >*/
/* signal added 0.10.22 */
gboolean (*do_latency) (GstBin *bin);
/*< private >*/
gpointer _gst_reserved[GST_PADDING-1];
};
GObjectGstObjectGstElementGstBin
成員函數
gobject_class->dispose = gst_element_dispose;
gobject_class->finalize = gst_element_finalize; gobject_class->set_property = gst_bin_set_property;
gobject_class->get_property = gst_bin_get_property;
Property-
enum
{
PROP_0,
PROP_ASYNC_HANDLING,
PROP_MESSAGE_FORWARD,
PROP_LAST
};
Signals
enum
{
PAD_ADDED,
PAD_REMOVED,
NO_MORE_PADS,
/* add more above */
LAST_SIGNAL
};
enum
{
ELEMENT_ADDED,
ELEMENT_REMOVED,
DO_LATENCY,
LAST_SIGNAL
};
User register signal handler
何時(shí)emit signal?
gst_element_add_pad ()
gst_element_remove_pad()
gst_element_no_more_pads()
klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
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struct _GstPipeline {
GstBin bin;
/*< public >*/ /* with LOCK */
GstClock *fixed_clock;
GstClockTime stream_time;
GstClockTime delay;
/*< private >*/
GstPipelinePrivate *priv;
gpointer _gst_reserved[GST_PADDING-1];
};
struct _GstPipelineClass {
GstBinClass parent_class;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GObjectGstObjectGstElementGstBinGstPipeline
成員函數
gobject_class->set_property = gst_bin_set_property;
gobject_class->get_property = gst_bin_get_property; override老祖宗：
gobject_class->set_property = gst_pipeline_set_property;
gobject_class->get_property = gst_pipeline_get_property;
gobject_class->dispose = gst_pipeline_dispose;
override父類(lèi)：
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_pipeline_change_state);
gstelement_class->provide_clock =
GST_DEBUG_FUNCPTR (gst_pipeline_provide_clock_func);
gstbin_class->handle_message =
GST_DEBUG_FUNCPTR (gst_pipeline_handle_message);
Property-
enum
{
PROP_0,
PROP_ASYNC_HANDLING,
PROP_MESSAGE_FORWARD,
PROP_LAST
};enum
{
PROP_0,
PROP_DELAY,
PROP_AUTO_FLUSH_BUS
};
Signals
enum
{
ELEMENT_ADDED,
ELEMENT_REMOVED,
DO_LATENCY,
LAST_SIGNAL
};
User register signal handler
何時(shí)emit signal?
klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
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