QImageCapture 类

QImageCapture 类用于媒体内容的录制。更多...

头：	#include <QImageCapture>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Multimedia) target_link_libraries(mytarget PRIVATE Qt6::Multimedia)
qmake:	QT += multimedia
继承：	QObject

所有成员列表，包括继承成员

公共类型

enum	Error { NoError, NotReadyError, ResourceError, OutOfSpaceError, NotSupportedFeatureError, FormatError }
enum	FileFormat { UnspecifiedFormat, JPEG, PNG, WebP, Tiff }
enum	Quality { VeryLowQuality, LowQuality, NormalQuality, HighQuality, VeryHighQuality }

特性

error : const Error
errorString : const QString
fileFormat : const FileFormat

metaData : QMediaMetaData
quality : const Quality
readyForCapture : const bool

公共函数

	QImageCapture (QObject * parent = nullptr)
virtual	~QImageCapture ()
void	addMetaData (const QMediaMetaData & metaData )
QMediaCaptureSession *	captureSession () const
QImageCapture::Error	error () const
QString	errorString () const
QImageCapture::FileFormat	fileFormat () const
bool	isAvailable () const
bool	isReadyForCapture () const
QMediaMetaData	metaData () const
QImageCapture::Quality	quality () const
QSize	resolution () const
void	setFileFormat (QImageCapture::FileFormat format )
void	setMetaData (const QMediaMetaData & metaData )
void	setQuality (QImageCapture::Quality quality )
void	setResolution (const QSize & resolution )
void	setResolution (int width , int height )

公共槽

int	capture ()
int	captureToFile (const QString & file = QString())

信号

void	errorChanged ()
void	errorOccurred (int id , QImageCapture::Error error , const QString & errorString )
void	fileFormatChanged ()
void	imageAvailable (int id , const QVideoFrame & frame )
void	imageCaptured (int id , const QImage & preview )
void	imageExposed (int id )
void	imageMetadataAvailable (int id , const QMediaMetaData & metaData )
void	imageSaved (int id , const QString & fileName )
void	metaDataChanged ()
void	qualityChanged ()
void	readyForCaptureChanged (bool ready )
void	resolutionChanged ()

静态公共成员

QString	fileFormatDescription (QImageCapture::FileFormat f )
QString	fileFormatName (QImageCapture::FileFormat f )
QList<QImageCapture::FileFormat>	supportedFormats ()

详细描述

The QImageCapture class is a high level images recording class. It's not intended to be used alone but for accessing the media recording functions of other media objects, like QCamera .

QMediaCaptureSession captureSession;
camera = new QCamera;
captureSession.setCamera(camera);
viewfinder = new QVideoWidget();
viewfinder->show();
captureSession.setVideoOutput(viewfinder);
imageCapture = new QImageCapture(camera);
captureSession.setImageCapture(imageCapture);
camera->start();
//on shutter button pressed
imageCapture->capture();

另请参阅 QCamera .

成员类型文档编制

enum QImageCapture:: Error

常量	值	描述
`QImageCapture::NoError`	`0`	没有错误。
`QImageCapture::NotReadyError`	`1`	The service is not ready for capture yet.
`QImageCapture::ResourceError`	`2`	设备未就绪 (或不可用)。
`QImageCapture::OutOfSpaceError`	`3`	设备没有剩余空间。
`QImageCapture::NotSupportedFeatureError`	`4`	Device does not support stillimages capture.
`QImageCapture::FormatError`	`5`	不支持当前格式。

enum QImageCapture:: FileFormat

Choose one of the following image formats:

常量	值	描述
`QImageCapture::UnspecifiedFormat`	`0`	No format specified
`QImageCapture::JPEG`	`1`	`.jpg` or `.jpeg` format
`QImageCapture::PNG`	`2`	`.png` format
`QImageCapture::WebP`	`3`	`.webp` format
`QImageCapture::Tiff`	`4`	`.tiff` format

enum QImageCapture:: Quality

枚举品质编码级别。

常量	值
`QImageCapture::VeryLowQuality`	`0`
`QImageCapture::LowQuality`	`1`
`QImageCapture::NormalQuality`	`2`
`QImageCapture::HighQuality`	`3`
`QImageCapture::VeryHighQuality`	`4`

特性文档编制

`[read-only]` error : const Error

返回当前错误状态。

访问函数：

QImageCapture::Error

error () const

通知程序信号：

void	errorChanged ()

另请参阅 errorString ().

`[read-only]` errorString : const QString

返回描述当前错误状态的字符串。

访问函数：

QString

errorString () const

通知程序信号：

void	errorChanged ()

另请参阅 error ().

`[read-only]` fileFormat : const FileFormat

This property holds the image format.

访问函数：

QImageCapture::FileFormat

fileFormat () const

通知程序信号：

void	fileFormatChanged ()

metaData : QMediaMetaData

This property holds the meta data that will get embedded into the image.

注意： Additional fields such as a time stamp or location may get added by the camera back end.

访问函数：

QMediaMetaData	metaData () const
void	setMetaData (const QMediaMetaData & metaData )

通知程序信号：

void	metaDataChanged ()

`[read-only]` quality : const Quality

This property holds the image encoding quality.

访问函数：

QImageCapture::Quality

quality () const

通知程序信号：

void	qualityChanged ()

`[read-only]` readyForCapture : const bool

保持 true if the camera is ready to capture an image immediately. Calling capture () while readyForCapture is false is not permitted and results in an error.

访问函数：

bool	isReadyForCapture () const

通知程序信号：

void	readyForCaptureChanged (bool ready )

成员函数文档编制

`[explicit]` QImageCapture:: QImageCapture ( QObject * parent = nullptr)

Constructs a image capture object, from a parent , that can capture individual still images produced by a camera.

You must connect both an image capture object and a QCamera to a capture session to capture images.

`[virtual noexcept]` QImageCapture:: ~QImageCapture ()

Destroys images capture object.

void QImageCapture:: addMetaData (const QMediaMetaData & metaData )

Adds additional metaData to any existing meta data, that is embedded into the captured image.

`[slot]` int QImageCapture:: capture ()

Capture the image and make it available as a QImage . This operation is asynchronous in majority of cases, followed by signals QImageCapture::imageExposed (), QImageCapture::imageCaptured () 或 QImageCapture::error ().

QImageCapture::capture returns the capture Id parameter, used with imageExposed (), imageCaptured () 和 imageSaved () 信号。

另请参阅 isReadyForCapture ().

QMediaCaptureSession *QImageCapture:: captureSession () const

Returns the capture session this camera is connected to, or a nullptr if the camera is not connected to a capture session.

使用 QMediaCaptureSession::setImageCapture () to connect the image capture to a session.

`[slot]` int QImageCapture:: captureToFile (const QString & file = QString())

Capture the image and save it to file . This operation is asynchronous in majority of cases, followed by signals QImageCapture::imageExposed (), QImageCapture::imageCaptured (), QImageCapture::imageSaved () 或 QImageCapture::error ().

If an empty file is passed, the camera back end chooses the default location and naming scheme for photos on the system, if only file name without full path is specified, the image will be saved to the default directory, with a full path reported with imageCaptured () 和 imageSaved () 信号。

QCamera saves all the capture parameters like exposure settings or image processing parameters, so changes to camera parameters after capture () is called do not affect previous capture requests.

QImageCapture::capture returns the capture Id parameter, used with imageExposed (), imageCaptured () 和 imageSaved () 信号。

另请参阅 isReadyForCapture ().

`[signal]` void QImageCapture:: errorOccurred ( int id , QImageCapture::Error error , const QString & errorString )

Signals that the capture request id has failed with an error and errorString description.

`[static]` QString QImageCapture:: fileFormatDescription ( QImageCapture::FileFormat f )

Returns the description of the given file format, f .

`[static]` QString QImageCapture:: fileFormatName ( QImageCapture::FileFormat f )

Returns the name of the given format, f .

`[signal]` void QImageCapture:: imageAvailable ( int id , const QVideoFrame & frame )

Signal emitted when the frame with request id 可用。

`[signal]` void QImageCapture:: imageCaptured ( int id , const QImage & preview )

Signal emitted when the frame with request id was captured, but not processed and saved yet. Frame preview can be displayed to user.

`[signal]` void QImageCapture:: imageExposed ( int id )

Signal emitted when the frame with request id was exposed.

`[signal]` void QImageCapture:: imageMetadataAvailable ( int id , const QMediaMetaData & metaData )

Signals that an image identified by id has metaData .

`[signal]` void QImageCapture:: imageSaved ( int id , const QString & fileName )

Signal emitted when QImageCapture::CaptureToFile is set and the frame with request id was saved to fileName .

bool QImageCapture:: isAvailable () const

Returns true if the images capture service ready to use.

`[signal]` void QImageCapture:: readyForCaptureChanged ( bool ready )

Signals that a camera's ready for capture state has changed.

注意： 通知程序信号对于特性 readyForCapture .

QSize QImageCapture:: resolution () const

返回编码图像的分辨率。

另请参阅 setResolution ().

`[signal]` void QImageCapture:: resolutionChanged ()

Signals when the image resolution changes.

void QImageCapture:: setFileFormat ( QImageCapture::FileFormat format )

设置图像 format .

另请参阅 fileFormat ().

void QImageCapture:: setMetaData (const QMediaMetaData & metaData )

Replaces any existing meta data, to be embedded into the captured image, with a set of metaData .

注意： setter 函数对于特性 metaData .

另请参阅 metaData ().

void QImageCapture:: setQuality ( QImageCapture::Quality quality )

设置图像编码 quality .

另请参阅 quality ().

void QImageCapture:: setResolution (const QSize & resolution )

设置 resolution 为编码图像。

空 QSize indicates the encoder should make an optimal choice based on what is available from the image source and the limitations of the codec.

另请参阅 resolution ().

void QImageCapture:: setResolution ( int width , int height )

设置 width and height of the resolution of the encoded image.

这是重载函数。

`[static]` QList < QImageCapture::FileFormat > QImageCapture:: supportedFormats ()

Returns a list of supported file formats.

另请参阅 FileFormat .

QImageCapture 类

公共类型

特性

公共函数

公共槽

信号

静态公共成员

详细描述

成员类型文档编制

enum QImageCapture:: Error

enum QImageCapture:: FileFormat

enum QImageCapture:: Quality

特性文档编制

[read-only] error : const Error

[read-only] errorString : const QString

[read-only] fileFormat : const FileFormat

metaData : QMediaMetaData

[read-only] quality : const Quality

[read-only] readyForCapture : const bool

成员函数文档编制

[explicit] QImageCapture:: QImageCapture ( QObject * parent = nullptr)

[virtual noexcept] QImageCapture:: ~QImageCapture ()

void QImageCapture:: addMetaData (const QMediaMetaData & metaData )

[slot] int QImageCapture:: capture ()

QMediaCaptureSession *QImageCapture:: captureSession () const

[slot] int QImageCapture:: captureToFile (const QString & file = QString())

[signal] void QImageCapture:: errorOccurred ( int id , QImageCapture::Error error , const QString & errorString )

[static] QString QImageCapture:: fileFormatDescription ( QImageCapture::FileFormat f )

[static] QString QImageCapture:: fileFormatName ( QImageCapture::FileFormat f )

[signal] void QImageCapture:: imageAvailable ( int id , const QVideoFrame & frame )

[signal] void QImageCapture:: imageCaptured ( int id , const QImage & preview )

[signal] void QImageCapture:: imageExposed ( int id )

[signal] void QImageCapture:: imageMetadataAvailable ( int id , const QMediaMetaData & metaData )

[signal] void QImageCapture:: imageSaved ( int id , const QString & fileName )

bool QImageCapture:: isAvailable () const

[signal] void QImageCapture:: readyForCaptureChanged ( bool ready )

QSize QImageCapture:: resolution () const

[signal] void QImageCapture:: resolutionChanged ()

void QImageCapture:: setFileFormat ( QImageCapture::FileFormat format )

void QImageCapture:: setMetaData (const QMediaMetaData & metaData )

void QImageCapture:: setQuality ( QImageCapture::Quality quality )

void QImageCapture:: setResolution (const QSize & resolution )

void QImageCapture:: setResolution ( int width , int height )

[static] QList < QImageCapture::FileFormat > QImageCapture:: supportedFormats ()

内容

`[read-only]` error : const Error

`[read-only]` errorString : const QString

`[read-only]` fileFormat : const FileFormat

`[read-only]` quality : const Quality

`[read-only]` readyForCapture : const bool

`[explicit]` QImageCapture:: QImageCapture ( QObject * parent = nullptr)

`[virtual noexcept]` QImageCapture:: ~QImageCapture ()

`[slot]` int QImageCapture:: capture ()

`[slot]` int QImageCapture:: captureToFile (const QString & file = QString())

`[signal]` void QImageCapture:: errorOccurred ( int id , QImageCapture::Error error , const QString & errorString )

`[static]` QString QImageCapture:: fileFormatDescription ( QImageCapture::FileFormat f )

`[static]` QString QImageCapture:: fileFormatName ( QImageCapture::FileFormat f )

`[signal]` void QImageCapture:: imageAvailable ( int id , const QVideoFrame & frame )

`[signal]` void QImageCapture:: imageCaptured ( int id , const QImage & preview )

`[signal]` void QImageCapture:: imageExposed ( int id )

`[signal]` void QImageCapture:: imageMetadataAvailable ( int id , const QMediaMetaData & metaData )

`[signal]` void QImageCapture:: imageSaved ( int id , const QString & fileName )

`[signal]` void QImageCapture:: readyForCaptureChanged ( bool ready )

`[signal]` void QImageCapture:: resolutionChanged ()

`[static]` QList < QImageCapture::FileFormat > QImageCapture:: supportedFormats ()