utility

Classes
struct	MMAL_WRAPPER_T
Typedefs
typedef struct MMAL_WRAPPER_T	MMAL_WRAPPER_T
typedef void(*	MMAL_WRAPPER_CALLBACK_T )(MMAL_WRAPPER_T *wrapper)
Functions
MMAL_STATUS_T	mmal_wrapper_create (MMAL_WRAPPER_T **wrapper, const char *name)
MMAL_STATUS_T	mmal_wrapper_port_enable (MMAL_PORT_T *port, uint32_t flags)
MMAL_STATUS_T	mmal_wrapper_port_disable (MMAL_PORT_T *port)
MMAL_STATUS_T	mmal_wrapper_buffer_get_empty (MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T **buffer, uint32_t flags)
MMAL_STATUS_T	mmal_wrapper_buffer_get_full (MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T **buffer, uint32_t flags)
MMAL_STATUS_T	mmal_wrapper_cancel (MMAL_WRAPPER_T *wrapper)
MMAL_STATUS_T	mmal_wrapper_destroy (MMAL_WRAPPER_T *wrapper)
MMAL wrapper flags
#define	MMAL_WRAPPER_FLAG_WAIT   1
#define	MMAL_WRAPPER_FLAG_PAYLOAD_ALLOCATE   2
#define	MMAL_WRAPPER_FLAG_PAYLOAD_USE_SHARED_MEMORY   4

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Detailed Description

The component wrapper utility functions can be used in place of common sequences of calls to the MMAL API in order to control a standalone component. It hides some of the complexity in using standalone components behind a fully synchronous interface.

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Define Documentation

#define MMAL_WRAPPER_FLAG_PAYLOAD_ALLOCATE   2

The pool for the port should allocate memory for the payloads

#define MMAL_WRAPPER_FLAG_PAYLOAD_USE_SHARED_MEMORY   4

The port will use shared memory payloads

#define MMAL_WRAPPER_FLAG_WAIT   1

The operation should be blocking

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Typedef Documentation

typedef void(* MMAL_WRAPPER_CALLBACK_T)(MMAL_WRAPPER_T *wrapper)

Definition of the callback used by a wrapper to signal back to the client that a buffer header is available either in the pool or in the output queue.

Parameters:

wrapper

Pointer to the wrapper

typedef struct MMAL_WRAPPER_T MMAL_WRAPPER_T

Forward type definition for a wrapper

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Function Documentation

MMAL_STATUS_T mmal_wrapper_buffer_get_empty	(	MMAL_PORT_T *	port,
		MMAL_BUFFER_HEADER_T **	buffer,
		uint32_t	flags
	)

Wait for an empty buffer to be available on a port.

Parameters:

port	port to get an empty buffer from
buffer	points to the retreived buffer on return
flags	specify MMAL_WRAPPER_FLAG_WAIT for a blocking operation

Returns:

MMAL_SUCCESS on success.

Wait for an empty buffer to be available on a port

MMAL_STATUS_T mmal_wrapper_buffer_get_full	(	MMAL_PORT_T *	port,
		MMAL_BUFFER_HEADER_T **	buffer,
		uint32_t	flags
	)

Wait for a full buffer to be available on a port.

Parameters:

port	port to get a full buffer from
buffer	points to the retreived buffer on return
flags	specify MMAL_WRAPPER_FLAG_WAIT for a blocking operation

Returns:

MMAL_SUCCESS on success.

Wait for a full buffer to be available on a port

MMAL_STATUS_T mmal_wrapper_cancel

(

MMAL_WRAPPER_T *

wrapper

)

Cancel any ongoing blocking operation on a component wrapper.

Parameters:

wrapper

The wrapper on which to cancel operations.

Returns:

MMAL_SUCCESS on success.

MMAL_STATUS_T mmal_wrapper_create	(	MMAL_WRAPPER_T **	wrapper,
		const char *	name
	)

Create a wrapper around a component. The wrapper shall include a pool of buffer headers for each port. The pools will be suitable for the current format of its associated port.

Parameters:

wrapper	The address of a wrapper pointer that will be set to point to the created wrapper.
name	The name of the component to create.

Returns:

MMAL_SUCCESS on success.

MMAL_STATUS_T mmal_wrapper_destroy

(

MMAL_WRAPPER_T *

wrapper

)

Destroy a wrapper. Destroys a component wrapper and any resources it owns.

Parameters:

wrapper

The wrapper to be destroyed.

Returns:

MMAL_SUCCESS on success.

MMAL_STATUS_T mmal_wrapper_port_disable

(

MMAL_PORT_T *

port

)

Disable a port on a component wrapper.

Parameters:

port	port to disable

Returns:

MMAL_SUCCESS on success.

MMAL_STATUS_T mmal_wrapper_port_enable	(	MMAL_PORT_T *	port,
		uint32_t	flags
	)

Enable a port on a component wrapper.

Parameters:

port	port to enable
flags	used to specify payload allocation flags for the pool

Returns:

MMAL_SUCCESS on success.