CollectPads

Manages a set of pads that operate in collect mode. This means that control is given to the manager of this object when all pads have data.

* Collectpads are created with gst_collect_pads_new(). A callback should then be installed with gst_collect_pads_set_function ().

* Pads are added to the collection with gst_collect_pads_add_pad()/ gst_collect_pads_remove_pad(). The pad has to be a sinkpad. When added, the chain, event and query functions of the pad are overridden. The element_private of the pad is used to store private information for the collectpads.

* For each pad, data is queued in the _chain function or by performing a pull_range.

* When data is queued on all pads in waiting mode, the callback function is called.

* Data can be dequeued from the pad with the gst_collect_pads_pop() method. One can peek at the data with the gst_collect_pads_peek() function. These functions will return %NULL if the pad received an EOS event. When all pads return %NULL from a gst_collect_pads_peek(), the element can emit an EOS event itself.

* Data can also be dequeued in byte units using the gst_collect_pads_available(), gst_collect_pads_read_buffer() and gst_collect_pads_flush() calls.

* Elements should call gst_collect_pads_start() and gst_collect_pads_stop() in their state change functions to start and stop the processing of the collectpads. The gst_collect_pads_stop() call should be called before calling the parent element state change function in the PAUSED_TO_READY state change to ensure no pad is blocked and the element can finish streaming.

* gst_collect_pads_set_waiting() sets a pad to waiting or non-waiting mode. CollectPads element is not waiting for data to be collected on non-waiting pads. Thus these pads may but need not have data when the callback is called. All pads are in waiting mode by default.

class CollectPads : ObjectGst {

protected

GstCollectPads* gstCollectPads;

GstCollectPads* getCollectPadsStruct(bool transferOwnership);

void* getStruct();

this(GstCollectPads* gstCollectPads, bool ownedRef);

static GType getType();

this();

GstCollectData* addPad(Pad pad, uint size, GstCollectDataDestroyNotify destroyNotify, bool lock);

uint available();

GstFlowReturn clipRunningTime(GstCollectData* cdata, Buffer buf, Buffer outbuf, void* userData);

bool eventDefault(GstCollectData* data, Event event, bool discard);

uint flush(GstCollectData* data, uint size);

Buffer peek(GstCollectData* data);

Buffer pop(GstCollectData* data);

bool queryDefault(GstCollectData* data, Query query, bool discard);

Buffer readBuffer(GstCollectData* data, uint size);

bool removePad(Pad pad);

void setBufferFunction(GstCollectPadsBufferFunction func, void* userData);

void setClipFunction(GstCollectPadsClipFunction clipfunc, void* userData);

void setCompareFunction(GstCollectPadsCompareFunction func, void* userData);

void setEventFunction(GstCollectPadsEventFunction func, void* userData);

void setFlushFunction(GstCollectPadsFlushFunction func, void* userData);

void setFlushing(bool flushing);

void setFunction(GstCollectPadsFunction func, void* userData);

void setQueryFunction(GstCollectPadsQueryFunction func, void* userData);

void setWaiting(GstCollectData* data, bool waiting);

bool srcEventDefault(Pad pad, Event event);

void start();

void stop();

Buffer takeBuffer(GstCollectData* data, uint size);

}

Constructors

this this(GstCollectPads* gstCollectPads, bool ownedRef): Sets our main struct and passes it to the parent class.
this this(): Create a new instance of #GstCollectPads.

Members

Functions

addPad GstCollectData* addPad(Pad pad, uint size, GstCollectDataDestroyNotify destroyNotify, bool lock): Add a pad to the collection of collect pads. The pad has to be a sinkpad. The refcount of the pad is incremented. Use gst_collect_pads_remove_pad() to remove the pad from the collection again.
available uint available(): Query how much bytes can be read from each queued buffer. This means that the result of this call is the maximum number of bytes that can be read from each of the pads.
clipRunningTime GstFlowReturn clipRunningTime(GstCollectData* cdata, Buffer buf, Buffer outbuf, void* userData): Convenience clipping function that converts incoming buffer's timestamp to running time, or clips the buffer if outside configured segment.
eventDefault bool eventDefault(GstCollectData* data, Event event, bool discard): Default #GstCollectPads event handling that elements should always chain up to to ensure proper operation. Element might however indicate event should not be forwarded downstream.
flush uint flush(GstCollectData* data, uint size): Flush @size bytes from the pad @data.
getCollectPadsStruct GstCollectPads* getCollectPadsStruct(bool transferOwnership): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
peek Buffer peek(GstCollectData* data): Peek at the buffer currently queued in @data. This function should be called with the @pads STREAM_LOCK held, such as in the callback handler.
pop Buffer pop(GstCollectData* data): Pop the buffer currently queued in @data. This function should be called with the @pads STREAM_LOCK held, such as in the callback handler.
queryDefault bool queryDefault(GstCollectData* data, Query query, bool discard): Default #GstCollectPads query handling that elements should always chain up to to ensure proper operation. Element might however indicate query should not be forwarded downstream.
readBuffer Buffer readBuffer(GstCollectData* data, uint size): Get a subbuffer of @size bytes from the given pad @data.
removePad bool removePad(Pad pad): Remove a pad from the collection of collect pads. This function will also free the #GstCollectData and all the resources that were allocated with gst_collect_pads_add_pad().
setBufferFunction void setBufferFunction(GstCollectPadsBufferFunction func, void* userData): Set the callback function and user data that will be called with the oldest buffer when all pads have been collected, or %NULL on EOS. If a buffer is passed, the callback owns a reference and must unref it.
setClipFunction void setClipFunction(GstCollectPadsClipFunction clipfunc, void* userData): Install a clipping function that is called right after a buffer is received on a pad managed by @pads. See #GstCollectPadsClipFunction for more info.
setCompareFunction void setCompareFunction(GstCollectPadsCompareFunction func, void* userData): Set the timestamp comparison function.
setEventFunction void setEventFunction(GstCollectPadsEventFunction func, void* userData): Set the event callback function and user data that will be called when collectpads has received an event originating from one of the collected pads. If the event being processed is a serialized one, this callback is called with @pads STREAM_LOCK held, otherwise not. As this lock should be held when calling a number of CollectPads functions, it should be acquired if so (unusually) needed.
setFlushFunction void setFlushFunction(GstCollectPadsFlushFunction func, void* userData): Install a flush function that is called when the internal state of all pads should be flushed as part of flushing seek handling. See #GstCollectPadsFlushFunction for more info.
setFlushing void setFlushing(bool flushing): Change the flushing state of all the pads in the collection. No pad is able to accept anymore data when @flushing is %TRUE. Calling this function with @flushing %FALSE makes @pads accept data again. Caller must ensure that downstream streaming (thread) is not blocked, e.g. by sending a FLUSH_START downstream.
setFunction void setFunction(GstCollectPadsFunction func, void* userData): CollectPads provides a default collection algorithm that will determine the oldest buffer available on all of its pads, and then delegate to a configured callback. However, if circumstances are more complicated and/or more control is desired, this sets a callback that will be invoked instead when all the pads added to the collection have buffers queued. Evidently, this callback is not compatible with gst_collect_pads_set_buffer_function() callback. If this callback is set, the former will be unset.
setQueryFunction void setQueryFunction(GstCollectPadsQueryFunction func, void* userData): Set the query callback function and user data that will be called after collectpads has received a query originating from one of the collected pads. If the query being processed is a serialized one, this callback is called with @pads STREAM_LOCK held, otherwise not. As this lock should be held when calling a number of CollectPads functions, it should be acquired if so (unusually) needed.
setWaiting void setWaiting(GstCollectData* data, bool waiting): Sets a pad to waiting or non-waiting mode, if at least this pad has not been created with locked waiting state, in which case nothing happens.
srcEventDefault bool srcEventDefault(Pad pad, Event event): Default #GstCollectPads event handling for the src pad of elements. Elements can chain up to this to let flushing seek event handling be done by #GstCollectPads.
start void start(): Starts the processing of data in the collect_pads.
stop void stop(): Stops the processing of data in the collect_pads. this function will also unblock any blocking operations.
takeBuffer Buffer takeBuffer(GstCollectData* data, uint size): Get a subbuffer of @size bytes from the given pad @data. Flushes the amount of read bytes.

Static functions

getType GType getType()

Variables

gstCollectPads GstCollectPads* gstCollectPads;: the main Gtk struct

Inherited Members

From ObjectGst

gstObject GstObject* gstObject;: the main Gtk struct
getObjectGstStruct GstObject* getObjectGstStruct(bool transferOwnership): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
getType GType getType()
checkUniqueness bool checkUniqueness(ListG list, string name): Checks to see if there is any object named @name in @list. This function does not do any locking of any kind. You might want to protect the provided list with the lock of the owner of the list. This function will lock each #GstObject in the list to compare the name, so be careful when passing a list with a locked object.
defaultDeepNotify void defaultDeepNotify(ObjectG object, ObjectGst orig, ParamSpec pspec, string[] excludedProps): A default deep_notify signal callback for an object. The user data should contain a pointer to an array of strings that should be excluded from the notify. The default handler will print the new value of the property using g_print.
refSink void* refSink(void* object): Increase the reference count of @object, and possibly remove the floating reference, if @object has a floating reference.
replace bool replace(ObjectGst oldobj, ObjectGst newobj): Atomically modifies a pointer to point to a new object. The reference count of @oldobj is decreased and the reference count of @newobj is increased.
addControlBinding bool addControlBinding(ControlBinding binding): Attach the #GstControlBinding to the object. If there already was a #GstControlBinding for this property it will be replaced.
defaultError void defaultError(ErrorG error, string debug_): A default error function that uses g_printerr() to display the error message and the optional debug string..
getControlBinding ControlBinding getControlBinding(string propertyName): Gets the corresponding #GstControlBinding for the property. This should be unreferenced again after use.
getControlRate GstClockTime getControlRate(): Obtain the control-rate for this @object. Audio processing #GstElement objects will use this rate to sub-divide their processing loop and call gst_object_sync_values() in between. The length of the processing segment should be up to @control-rate nanoseconds.
getGValueArray bool getGValueArray(string propertyName, GstClockTime timestamp, GstClockTime interval, Value[] values): Gets a number of #GValues for the given controlled property starting at the requested time. The array @values need to hold enough space for @n_values of #GValue.
getName string getName(): Returns a copy of the name of @object. Caller should g_free() the return value after usage. For a nameless object, this returns %NULL, which you can safely g_free() as well.
getParent ObjectGst getParent(): Returns the parent of @object. This function increases the refcount of the parent object so you should gst_object_unref() it after usage.
getPathString string getPathString(): Generates a string describing the path of @object in the object hierarchy. Only useful (or used) for debugging.
getValue Value getValue(string propertyName, GstClockTime timestamp): Gets the value for the given controlled property at the requested time.
getValueArray bool getValueArray(string propertyName, GstClockTime timestamp, GstClockTime interval, uint nValues, void* values): Gets a number of values for the given controlled property starting at the requested time. The array @values need to hold enough space for @n_values of the same type as the objects property's type.
hasActiveControlBindings bool hasActiveControlBindings(): Check if the @object has active controlled properties.
hasAncestor bool hasAncestor(ObjectGst ancestor): Check if @object has an ancestor @ancestor somewhere up in the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
hasAsAncestor bool hasAsAncestor(ObjectGst ancestor): Check if @object has an ancestor @ancestor somewhere up in the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
hasAsParent bool hasAsParent(ObjectGst parent): Check if @parent is the parent of @object. E.g. a #GstElement can check if it owns a given #GstPad.
doref alias doref = ref_: Undocumented in source.
ref_ ObjectGst ref_(): Increments the reference count on @object. This function does not take the lock on @object because it relies on atomic refcounting.
removeControlBinding bool removeControlBinding(ControlBinding binding): Removes the corresponding #GstControlBinding. If it was the last ref of the binding, it will be disposed.
setControlBindingDisabled void setControlBindingDisabled(string propertyName, bool disabled): This function is used to disable the control bindings on a property for some time, i.e. gst_object_sync_values() will do nothing for the property.
setControlBindingsDisabled void setControlBindingsDisabled(bool disabled): This function is used to disable all controlled properties of the @object for some time, i.e. gst_object_sync_values() will do nothing.
setControlRate void setControlRate(GstClockTime controlRate): Change the control-rate for this @object. Audio processing #GstElement objects will use this rate to sub-divide their processing loop and call gst_object_sync_values() in between. The length of the processing segment should be up to @control-rate nanoseconds.
setName bool setName(string name): Sets the name of @object, or gives @object a guaranteed unique name (if @name is %NULL). This function makes a copy of the provided name, so the caller retains ownership of the name it sent.
setParent bool setParent(ObjectGst parent): Sets the parent of @object to @parent. The object's reference count will be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
suggestNextSync GstClockTime suggestNextSync(): Returns a suggestion for timestamps where buffers should be split to get best controller results.
syncValues bool syncValues(GstClockTime timestamp): Sets the properties of the object, according to the #GstControlSources that (maybe) handle them and for the given timestamp.
unparent void unparent(): Clear the parent of @object, removing the associated reference. This function decreases the refcount of @object.
unref void unref(): Decrements the reference count on @object. If reference count hits zero, destroy @object. This function does not take the lock on @object as it relies on atomic refcounting.
addOnDeepNotify gulong addOnDeepNotify(void delegate(ObjectGst, ParamSpec, ObjectGst) dlg, ConnectFlags connectFlags): The deep notify signal is used to be notified of property changes. It is typically attached to the toplevel bin to receive notifications from all the elements contained in that bin.