Helper class for using a GstAppSrc. More...
|GstAppSrc *||appSrc ()|
|bool||blockEnabled () const|
|CapsPtr||caps () const|
|ElementPtr||element () const|
|void||enableBlock (bool enable)|
|Format||format () const|
|bool||isLive () const|
|void||lazyConstruct (ApplicationSource *self)|
|quint64||maxBytes () const|
|quint64||maxLatency () const|
|quint64||minLatency () const|
|uint||minPercent () const|
|FlowReturn||pushBuffer (const BufferPtr &buffer)|
|void||setCallbacks (ApplicationSource *self)|
|void||setCaps (const CapsPtr &caps)|
|void||setElement (const ElementPtr &appsrc)|
|void||setFormat (Format f)|
|void||setLatency (quint64 min, quint64 max)|
|void||setLive (bool islive)|
|void||setMaxBytes (quint64 max)|
|void||setMinPercent (uint min)|
|void||setSize (qint64 size)|
|void||setStreamType (AppStreamType type)|
|qint64||size () const|
|AppStreamType||streamType () const|
|virtual void||enoughData ()|
|virtual void||needData (uint length)|
|virtual bool||seekData (quint64 offset)|
|virtual void||reservedVirtual1 ()|
|virtual void||reservedVirtual2 ()|
|virtual void||reservedVirtual3 ()|
|virtual void||reservedVirtual4 ()|
|static void||enough_data (GstAppSrc *src, gpointer user_data)|
|static void||enough_data_noop (GstAppSrc *, gpointer)|
|static void||need_data (GstAppSrc *src, guint length, gpointer user_data)|
|static void||need_data_noop (GstAppSrc *, guint, gpointer)|
|static gboolean||seek_data (GstAppSrc *src, guint64 offset, gpointer user_data)|
|static gboolean||seek_data_noop (GstAppSrc *, guint64, gpointer)|
Helper class for using a GstAppSrc.
Appsrc is an element that can be used by applications to insert data into a GStreamer pipeline. Unlike most GStreamer elements, appsrc provides external API functions. This class exports those API functions in the bindings and makes it easy to implement a custom source.
Before operating appsrc, the caps() must be set to a fixed caps describing the format of the data that will be pushed with appsrc. An exception to this is when pushing buffers with unknown caps, in which case no caps should be set. This is typically true of file-like sources that push raw byte buffers.
The main way of handing data to the appsrc element is by calling the pushBuffer() method. This will put the buffer onto a queue from which appsrc will read from in its streaming thread. It is important to note that data transport will not happen from the thread that performed the pushBuffer() call.
maxBytes() controls how much data can be queued in appsrc before appsrc considers the queue full. A filled internal queue will always cause enoughData() to be called, which signals the application that it should stop pushing data into appsrc. Use setBlock() to cause appsrc to block the pushBuffer() method until free data becomes available again.
When the internal queue is running out of data, the needData() function is called, which signals the application that it should start pushing more data into appsrc.
In addition to the needData() and enoughData() functions, appsrc can also call the seekData() function when streamMode() is set to AppStreamTypeSeekable or AppStreamTypeRandomAccess. The seekData() argument will contain the new desired position in the stream expressed in the unit set with setFormat(). After seekData() has been called, the application should push buffers from the new position.
Appsrc can operate in two different ways:
In all modes, the size() should contain the total stream size in bytes. Setting the size is mandatory in the AppStreamTypeRandomAccess mode. For the AppStreamTypeStream and AppStreamTypeSeekable modes, setting the size is optional but recommended.
When the application is finished pushing data into appsrc, it should call endOfStream(). After this call, no more buffers can be pushed into appsrc until a flushing seek happened or the state of the appsrc has gone through READY.