fast-yolo4/3rdparty/opencv/inc/opencv2/gapi/gframe.hpp
2024-09-25 09:43:03 +08:00

113 lines
3.4 KiB
C++

// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.
//
// Copyright (C) 2020 Intel Corporation
#ifndef OPENCV_GAPI_GFRAME_HPP
#define OPENCV_GAPI_GFRAME_HPP
#include <ostream>
#include <memory> // std::shared_ptr
#include <opencv2/gapi/opencv_includes.hpp>
#include <opencv2/gapi/gcommon.hpp> // GShape
#include <opencv2/gapi/gmat.hpp>
#include <opencv2/gapi/own/assert.hpp>
// TODO GAPI_EXPORTS or so
namespace cv
{
// Forward declaration; GNode and GOrigin are an internal
// (user-inaccessible) classes.
class GNode;
struct GOrigin;
/** \addtogroup gapi_data_objects
* @{
*/
/**
* @brief GFrame class represents an image or media frame in the graph.
*
* GFrame doesn't store any data itself, instead it describes a
* functional relationship between operations consuming and producing
* GFrame objects.
*
* GFrame is introduced to handle various media formats (e.g., NV12 or
* I420) under the same type. Various image formats may differ in the
* number of planes (e.g. two for NV12, three for I420) and the pixel
* layout inside. GFrame type allows to handle these media formats in
* the graph uniformly -- the graph structure will not change if the
* media format changes, e.g. a different camera or decoder is used
* with the same graph. G-API provides a number of operations which
* operate directly on GFrame, like `infer<>()` or
* renderFrame(); these operations are expected to handle different
* media formats inside. There is also a number of accessor
* operations like BGR(), Y(), UV() -- these operations provide
* access to frame's data in the familiar cv::GMat form, which can be
* used with the majority of the existing G-API operations. These
* accessor functions may perform color space converion on the fly if
* the image format of the GFrame they are applied to differs from the
* operation's semantic (e.g. the BGR() accessor is called on an NV12
* image frame).
*
* GFrame is a virtual counterpart of cv::MediaFrame.
*
* @sa cv::MediaFrame, cv::GFrameDesc, BGR(), Y(), UV(), infer<>().
*/
class GAPI_EXPORTS_W_SIMPLE GFrame
{
public:
/**
* @brief Constructs an empty GFrame
*
* Normally, empty G-API data objects denote a starting point of
* the graph. When an empty GFrame is assigned to a result of some
* operation, it obtains a functional link to this operation (and
* is not empty anymore).
*/
GAPI_WRAP GFrame(); // Empty constructor
/// @private
GFrame(const GNode &n, std::size_t out); // Operation result constructor
/// @private
GOrigin& priv(); // Internal use only
/// @private
const GOrigin& priv() const; // Internal use only
private:
std::shared_ptr<GOrigin> m_priv;
};
/** @} */
enum class MediaFormat: int
{
BGR = 0,
NV12,
};
/**
* \addtogroup gapi_meta_args
* @{
*/
struct GAPI_EXPORTS GFrameDesc
{
MediaFormat fmt;
cv::Size size;
bool operator== (const GFrameDesc &) const;
};
static inline GFrameDesc empty_gframe_desc() { return GFrameDesc{}; }
/** @} */
class MediaFrame;
GAPI_EXPORTS GFrameDesc descr_of(const MediaFrame &frame);
GAPI_EXPORTS std::ostream& operator<<(std::ostream& os, const cv::GFrameDesc &desc);
} // namespace cv
#endif // OPENCV_GAPI_GFRAME_HPP