cv::MediaFrame Class Reference

cv::MediaFrame class represents an image/media frame obtained from an external source. More...

#include <opencv2/gapi/media.hpp>

Collaboration diagram for cv::MediaFrame:

Classes
class	IAdapter
	An interface class for MediaFrame data adapters. More...
class	View
	Provides access to the MediaFrame's underlying data. More...

Public Types
enum class	Access {   R ,   W }
using	AdapterPtr = std::unique_ptr< IAdapter >

Public Member Functions
	MediaFrame ()
	Constructs an empty MediaFrame.
	MediaFrame (AdapterPtr &&p)
	Constructs a MediaFrame with the given Adapter. MediaFrame takes ownership over the passed adapter.
View	access (Access mode) const
	Obtain access to the underlying data with the given mode.
cv::GFrameDesc	desc () const
	Returns a media frame descriptor – the information about the media format, dimensions, etc.
template<typename T >
T *	get () const
	Casts and returns the associated MediaFrame adapter to the particular adapter type T, returns nullptr if the type is different.
void	serialize (cv::gapi::s11n::IOStream &os) const
	Serialize MediaFrame's data to a byte array.

Static Public Member Functions
template<class T , class... Args>
static cv::MediaFrame	Create (Args &&... args)
	Constructs a MediaFrame with the given parameters for the Adapter. The adapter of type T is costructed on the fly.

Detailed Description

cv::MediaFrame class represents an image/media frame obtained from an external source.

cv::MediaFrame represents image data as specified in cv::MediaFormat. cv::MediaFrame is designed to be a thin wrapper over some external memory of buffer; the class itself provides an uniform interface over such types of memory. cv::MediaFrame wraps data from a camera driver or from a media codec and provides an abstraction layer over this memory to G-API. MediaFrame defines a compact interface to access and manage the underlying data; the implementation is fully defined by the associated Adapter (which is usually user-defined).

See also

cv::RMat

Member Typedef Documentation

AdapterPtr

using cv::MediaFrame::AdapterPtr = std::unique_ptr<IAdapter>

Member Enumeration Documentation

Access

enum class cv::MediaFrame::Access

strong

This enum defines different types of cv::MediaFrame provided access to the underlying data. Note that different flags can't be combined in this version.

Enumerator
R	Access data for reading.
W	Access data for writing.

Constructor & Destructor Documentation

MediaFrame() [1/2]

cv::MediaFrame::MediaFrame

(

)

Constructs an empty MediaFrame.

The constructed object has no any data associated with it.

MediaFrame() [2/2]

cv::MediaFrame::MediaFrame ( AdapterPtr &&  p )

explicit

Constructs a MediaFrame with the given Adapter. MediaFrame takes ownership over the passed adapter.

Parameters

p	an unique pointer to instance of IAdapter derived class.

Member Function Documentation

access()

View cv::MediaFrame::access

(

Access

mode

)

const

Obtain access to the underlying data with the given mode.

Depending on the associated Adapter and the data wrapped, this method may be cheap (e.g., the underlying memory is local) or costly (if the underlying memory is external or device memory).

Parameters

mode	an access mode flag

Returns

a MediaFrame::View object. The views should be handled carefully, refer to the MediaFrame::View documentation for details.

desc()

cv::GFrameDesc cv::MediaFrame::desc

(

)

const

Returns a media frame descriptor – the information about the media format, dimensions, etc.

Returns

a cv::GFrameDesc

get()

template<typename T >

T * cv::MediaFrame::get ( ) const

inline

Casts and returns the associated MediaFrame adapter to the particular adapter type T, returns nullptr if the type is different.

This method may be useful if the adapter type is known by the caller, and some lower level access to the memory is required. Depending on the memory type, it may be more efficient than access().

Returns

a pointer to the adapter object, nullptr if the adapter type is different.

serialize()

void cv::MediaFrame::serialize

(

cv::gapi::s11n::IOStream &

os

)

const

Serialize MediaFrame's data to a byte array.

Note

The actual logic is implemented by frame's adapter class. Does nothing by default.

Parameters

os	Bytestream to store serialized MediaFrame data in.

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The documentation for this class was generated from the following file:

• opencv2/gapi/media.hpp