Video writer class. More...

#include "videoio.hpp"

Public Member Functions
	VideoWriter ()
	VideoWriter constructors. More...

	VideoWriter (const String &filename, int fourcc, double fps, Size frameSize, bool isColor=true)

virtual	~VideoWriter ()

virtual double	get (int propId) const
	Returns the specified VideoWriter property. More...

virtual bool	isOpened () const
	Returns true if video writer has been successfully initialized. More...

virtual bool	open (const String &filename, int fourcc, double fps, Size frameSize, bool isColor=true)
	Initializes or reinitializes video writer. More...

virtual VideoWriter &	operator<< (const Mat &image)

virtual void	release ()
	Closes the video writer. More...

virtual bool	set (int propId, double value)
	Sets a property in the VideoWriter. More...

virtual void	write (const Mat &image)
	Writes the next video frame. More...

Static Public Member Functions
static int	fourcc (char c1, char c2, char c3, char c4)
	Concatenates 4 chars to a fourcc code. More...

Static Protected Member Functions
static Ptr< IVideoWriter >	create (const String &filename, int fourcc, double fps, Size frameSize, bool isColor=true)

Protected Attributes
Ptr< IVideoWriter >	iwriter

Ptr< CvVideoWriter >	writer

Detailed Description

Video writer class.

Constructor & Destructor Documentation

cv::VideoWriter::VideoWriter ( )

VideoWriter constructors.

The constructors/functions initialize video writers. On Linux FFMPEG is used to write videos; on Windows FFMPEG or VFW is used; on MacOSX QTKit is used.

cv::VideoWriter::VideoWriter	(	const String &	filename,
		int	fourcc,
		double	fps,
		Size	frameSize,
		bool	isColor = `true`
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

filename	Name of the output video file.
fourcc	4-character code of codec used to compress the frames. For example, VideoWriter::fourcc('P','I','M','1') is a MPEG-1 codec, VideoWriter::fourcc('M','J','P','G') is a motion-jpeg codec etc. List of codes can be obtained at Video Codecs by FOURCC page. FFMPEG backend with MP4 container natively uses other values as fourcc code: see ObjectType, so you may receive a warning message from OpenCV about fourcc code conversion.
fps	Framerate of the created video stream.
frameSize	Size of the video frames.
isColor	If it is not zero, the encoder will expect and encode color frames, otherwise it will work with grayscale frames (the flag is currently supported on Windows only).

virtual cv::VideoWriter::~VideoWriter ( )

virtual

Member Function Documentation

static Ptr<IVideoWriter> cv::VideoWriter::create	(	const String &	filename,
		int	fourcc,
		double	fps,
		Size	frameSize,
		bool	isColor = `true`
	)

staticprotected

static int cv::VideoWriter::fourcc	(	char	c1,
		char	c2,
		char	c3,
		char	c4
	)

static

Concatenates 4 chars to a fourcc code.

This static method constructs the fourcc code of the codec to be used in the constructor VideoWriter::VideoWriter or VideoWriter::open.

virtual double cv::VideoWriter::get ( int propId ) const

virtual

Returns the specified VideoWriter property.

Parameters

propId

Property identifier. It can be one of the following:

VIDEOWRITER_PROP_QUALITY Current quality of the encoded videostream.
VIDEOWRITER_PROP_FRAMEBYTES (Read-only) Size of just encoded video frame; note that the encoding order may be different from representation order.
VIDEOWRITER_PROP_NSTRIPES Number of stripes for parallel encoding

Note: When querying a property that is not supported by the backend used by the VideoWriter class, value 0 is returned.

virtual bool cv::VideoWriter::isOpened ( ) const

virtual

Returns true if video writer has been successfully initialized.

virtual bool cv::VideoWriter::open	(	const String &	filename,
		int	fourcc,
		double	fps,
		Size	frameSize,
		bool	isColor = `true`
	)

virtual

Initializes or reinitializes video writer.

The method opens video writer. Parameters are the same as in the constructor VideoWriter::VideoWriter.

virtual VideoWriter& cv::VideoWriter::operator<< ( const Mat & image )

virtual

virtual void cv::VideoWriter::release ( )

virtual

Closes the video writer.

The methods are automatically called by subsequent VideoWriter::open and by the VideoWriter destructor.

virtual bool cv::VideoWriter::set	(	int	propId,
		double	value
	)

virtual

Sets a property in the VideoWriter.

Parameters

propId	Property identifier. It can be one of the following: VIDEOWRITER_PROP_QUALITY Quality (0..100%) of the videostream encoded. Can be adjusted dynamically in some codecs. VIDEOWRITER_PROP_NSTRIPES Number of stripes for parallel encoding
value	Value of the property.

virtual void cv::VideoWriter::write ( const Mat & image )

virtual

Writes the next video frame.

Parameters

image The written frame

The functions/methods write the specified image to video file. It must have the same size as has been specified when opening the video writer.

Member Data Documentation

Ptr<IVideoWriter> cv::VideoWriter::iwriter

protected

Ptr<CvVideoWriter> cv::VideoWriter::writer

protected

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

videoio/include/opencv2/videoio.hpp

Public Member Functions

Static Public Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation