Graph Utility

Classes
struct	MMAL_GRAPH_T
Typedefs
typedef struct MMAL_GRAPH_T	MMAL_GRAPH_T
typedef void(*	MMAL_GRAPH_EVENT_CB )(MMAL_GRAPH_T *graph, MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T *buffer, void *cb_data)
Functions
MMAL_STATUS_T	mmal_graph_create (MMAL_GRAPH_T **graph, unsigned int userdata_size)
MMAL_STATUS_T	mmal_graph_add_component (MMAL_GRAPH_T *graph, MMAL_COMPONENT_T *component)
MMAL_STATUS_T	mmal_graph_add_port (MMAL_GRAPH_T *graph, MMAL_PORT_T *port)
MMAL_STATUS_T	mmal_graph_add_connection (MMAL_GRAPH_T *graph, MMAL_CONNECTION_T *connection)
MMAL_STATUS_T	mmal_graph_new_component (MMAL_GRAPH_T *graph, const char *name, MMAL_COMPONENT_T **component)
MMAL_STATUS_T	mmal_graph_new_connection (MMAL_GRAPH_T *graph, MMAL_PORT_T *out, MMAL_PORT_T *in, uint32_t flags, MMAL_CONNECTION_T **connection)
MMAL_STATUS_T	mmal_graph_enable (MMAL_GRAPH_T *graph, MMAL_GRAPH_EVENT_CB cb, void *cb_data)
MMAL_STATUS_T	mmal_graph_disable (MMAL_GRAPH_T *graph)
MMAL_PORT_T *	mmal_graph_find_port (MMAL_GRAPH_T *graph, const char *name, MMAL_PORT_TYPE_T type, unsigned index)
MMAL_STATUS_T	mmal_graph_build (MMAL_GRAPH_T *ctx, const char *name, MMAL_COMPONENT_T **component)
MMAL_STATUS_T	mmal_graph_component_constructor (const char *name, MMAL_COMPONENT_T *component)
MMAL_STATUS_T	mmal_graph_destroy (MMAL_GRAPH_T *ctx)

---

Detailed Description

The graph utility functions allows one to easily create graphs of MMAL components.

---

Typedef Documentation

typedef void(* MMAL_GRAPH_EVENT_CB)(MMAL_GRAPH_T *graph, MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T *buffer, void *cb_data)

Definition of the callback used by a graph to send events to the client.

Parameters:

graph	the graph sending the event
port	the port which generated the event
buffer	the buffer header containing the event data
cb_data	data passed back to the client when the callback is invoked

typedef struct MMAL_GRAPH_T MMAL_GRAPH_T

Structure describing a graph

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Function Documentation

MMAL_STATUS_T mmal_graph_add_component	(	MMAL_GRAPH_T *	graph,
		MMAL_COMPONENT_T *	component
	)

Add a component to a graph. Allows the client to add a component to the graph.

Parameters:

graph	instance of the graph
component	component to add to a graph

Returns:

MMAL_SUCCESS on success

MMAL_STATUS_T mmal_graph_add_connection	(	MMAL_GRAPH_T *	graph,
		MMAL_CONNECTION_T *	connection
	)

Add a connection to a graph. Allows the client to add an internal connection to a graph.

Parameters:

graph	instance of the graph
connection	connection to add to the graph

Returns:

MMAL_SUCCESS on success

MMAL_STATUS_T mmal_graph_add_port	(	MMAL_GRAPH_T *	graph,
		MMAL_PORT_T *	port
	)

Add a port to a graph. Allows the client to add an input or output port to a graph. The given port will effectively become an end point for the graph.

Parameters:

graph	instance of the graph
port	port to add to the graph

Returns:

MMAL_SUCCESS on success

MMAL_STATUS_T mmal_graph_build	(	MMAL_GRAPH_T *	ctx,
		const char *	name,
		MMAL_COMPONENT_T **	component
	)

Create an instance of a component from a graph. The newly created component will expose input and output ports to the client. Not that all the exposed ports will be in a disabled state by default.

Parameters:

graph	graph to create the component from
name	name of the component to create
component	returned component

Returns:

MMAL_SUCCESS on success

MMAL_STATUS_T mmal_graph_component_constructor	(	const char *	name,
		MMAL_COMPONENT_T *	component
	)

Component constructor for a graph. FIXME: private function

Parameters:

name	name of the component to create
component	component

Returns:

MMAL_SUCCESS on success

MMAL_STATUS_T mmal_graph_create	(	MMAL_GRAPH_T **	graph,
		unsigned int	userdata_size
	)

Create an instance of a graph. The newly created graph will need to be populated by the client.

Parameters:

graph	returned graph
userdata_size	size to be allocated for the userdata field

Returns:

MMAL_SUCCESS on success

MMAL_STATUS_T mmal_graph_destroy

(

MMAL_GRAPH_T *

ctx

)

Destroy a previously created graph

Parameters:

graph

graph to destroy

Returns:

MMAL_SUCCESS on success

MMAL_STATUS_T mmal_graph_enable	(	MMAL_GRAPH_T *	graph,
		MMAL_GRAPH_EVENT_CB	cb,
		void *	cb_data
	)

Enable the graph and start processing.

Parameters:

graph	the graph to enable
cb	the callback to invoke when an event occurs on any of the internal control ports
cb_data	data passed back to the client when the callback is invoked

Returns:

MMAL_SUCCESS on success

MMAL_PORT_T* mmal_graph_find_port	(	MMAL_GRAPH_T *	graph,
		const char *	name,
		MMAL_PORT_TYPE_T	type,
		unsigned	index
	)

Find a port in the graph.

Parameters:

graph	graph instance
name	name of the component of interest
type	type of port (in/out)
index	which port index within the component

Returns:

port, or NULL if not found

MMAL_STATUS_T mmal_graph_new_component	(	MMAL_GRAPH_T *	graph,
		const char *	name,
		MMAL_COMPONENT_T **	component
	)

Create a new component and add it to a graph. Allows the client to create and add a component to the graph.

Parameters:

graph	instance of the graph
name	name of the component to create
component	if not NULL, will contain a pointer to the created component

Returns:

MMAL_SUCCESS on success

MMAL_STATUS_T mmal_graph_new_connection	(	MMAL_GRAPH_T *	graph,
		MMAL_PORT_T *	out,
		MMAL_PORT_T *	in,
		uint32_t	flags,
		MMAL_CONNECTION_T **	connection
	)

Create and add a connection to a graph. Allows the client to create and add an internal connection to a graph.

Parameters:

graph	instance of the graph
out	the output port to use for the connection
in	the input port to use for the connection
flags	the flags specifying which type of connection should be created
connection	if not NULL, will contain a pointer to the created connection

Returns:

MMAL_SUCCESS on success