Video writer class. More...

Inheritance diagram for OpenCVForUnity.VideoioModule.VideoWriter:

Public Member Functions
IntPtr	getNativeObjAddr ()

	VideoWriter ()
	Default constructors. More...

	VideoWriter (string filename, int fourcc, double fps, Size frameSize, bool isColor)

	VideoWriter (string filename, int fourcc, double fps, Size frameSize)

	VideoWriter (string filename, int apiPreference, int fourcc, double fps, Size frameSize, bool isColor)

	VideoWriter (string filename, int apiPreference, int fourcc, double fps, Size frameSize)

	VideoWriter (string filename, int fourcc, double fps, Size frameSize, MatOfInt _params)

	VideoWriter (string filename, int apiPreference, int fourcc, double fps, Size frameSize, MatOfInt _params)

bool	open (string filename, int fourcc, double fps, Size frameSize, bool isColor)
	Initializes or reinitializes video writer. More...

bool	open (string filename, int fourcc, double fps, Size frameSize)
	Initializes or reinitializes video writer. More...

bool	open (string filename, int apiPreference, int fourcc, double fps, Size frameSize, bool isColor)

bool	open (string filename, int apiPreference, int fourcc, double fps, Size frameSize)

bool	open (string filename, int fourcc, double fps, Size frameSize, MatOfInt _params)

bool	open (string filename, int apiPreference, int fourcc, double fps, Size frameSize, MatOfInt _params)

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

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

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

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

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

string	getBackendName ()
	Returns used backend API name. More...

Public Member Functions inherited from OpenCVForUnity.DisposableObject
void	Dispose ()

void	ThrowIfDisposed ()

Static Public Member Functions
static VideoWriter	__fromPtr__ (IntPtr addr)

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

Static Public Member Functions inherited from OpenCVForUnity.DisposableObject
static IntPtr	ThrowIfNullIntPtr (IntPtr ptr)

Protected Member Functions
override void	Dispose (bool disposing)

Protected Member Functions inherited from OpenCVForUnity.DisposableOpenCVObject
	DisposableOpenCVObject ()

	DisposableOpenCVObject (IntPtr ptr)

	DisposableOpenCVObject (bool isEnabledDispose)

	DisposableOpenCVObject (IntPtr ptr, bool isEnabledDispose)

Protected Member Functions inherited from OpenCVForUnity.DisposableObject
	DisposableObject ()

	DisposableObject (bool isEnabledDispose)

Additional Inherited Members
Properties inherited from OpenCVForUnity.DisposableObject
bool	IsDisposed `[get, protected set]`

bool	IsEnabledDispose `[get, set]`

Detailed Description

Video writer class.

The class provides C++ API for writing video files or image sequences.

Constructor & Destructor Documentation

◆ VideoWriter() [1/7]

OpenCVForUnity.VideoioModule.VideoWriter.VideoWriter ( )

Default constructors.

The constructors/functions initialize video writers.

On Linux FFMPEG is used to write videos;
On Windows FFMPEG or MSWF or DSHOW is used;
On MacOSX AVFoundation is used.

◆ VideoWriter() [2/7]

OpenCVForUnity.VideoioModule.VideoWriter.VideoWriter	(	string	filename,
		int	fourcc,
		double	fps,
		Size	frameSize,
		bool	isColor
	)

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 MSDN page or with this page of the fourcc site for a more complete list). 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.

Tips:

With some backends fourcc=-1 pops up the codec selection dialog from the system.
To save image sequence use a proper filename (eg. img_%02d.jpg) and fourcc=0 OR fps=0. Use uncompressed image format (eg. img_%02d.BMP) to save raw frames.
Most codecs are lossy. If you want lossless video file you need to use a lossless codecs (eg. FFMPEG FFV1, Huffman HFYU, Lagarith LAGS, etc...)
If FFMPEG is enabled, using codec=0; fps=0; you can create an uncompressed (raw) video file.
If FFMPEG is used, we allow frames of odd width or height, but in this case we truncate the rightmost column/the bottom row. Probably, this should be handled more elegantly, but some internal functions inside FFMPEG swscale require even width/height.

◆ VideoWriter() [3/7]

OpenCVForUnity.VideoioModule.VideoWriter.VideoWriter	(	string	filename,
		int	fourcc,
		double	fps,
		Size	frameSize
	)

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 MSDN page or with this page of the fourcc site for a more complete list). 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.

Tips:

With some backends fourcc=-1 pops up the codec selection dialog from the system.
To save image sequence use a proper filename (eg. img_%02d.jpg) and fourcc=0 OR fps=0. Use uncompressed image format (eg. img_%02d.BMP) to save raw frames.
Most codecs are lossy. If you want lossless video file you need to use a lossless codecs (eg. FFMPEG FFV1, Huffman HFYU, Lagarith LAGS, etc...)
If FFMPEG is enabled, using codec=0; fps=0; you can create an uncompressed (raw) video file.
If FFMPEG is used, we allow frames of odd width or height, but in this case we truncate the rightmost column/the bottom row. Probably, this should be handled more elegantly, but some internal functions inside FFMPEG swscale require even width/height.

◆ VideoWriter() [4/7]

OpenCVForUnity.VideoioModule.VideoWriter.VideoWriter	(	string	filename,
		int	apiPreference,
		int	fourcc,
		double	fps,
		Size	frameSize,
		bool	isColor
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. The apiPreference parameter allows to specify API backends to use. Can be used to enforce a specific reader implementation if multiple are available: e.g. cv::CAP_FFMPEG or cv::CAP_GSTREAMER.

◆ VideoWriter() [5/7]

OpenCVForUnity.VideoioModule.VideoWriter.VideoWriter	(	string	filename,
		int	apiPreference,
		int	fourcc,
		double	fps,
		Size	frameSize
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. The apiPreference parameter allows to specify API backends to use. Can be used to enforce a specific reader implementation if multiple are available: e.g. cv::CAP_FFMPEG or cv::CAP_GSTREAMER.

◆ VideoWriter() [6/7]

OpenCVForUnity.VideoioModule.VideoWriter.VideoWriter	(	string	filename,
		int	fourcc,
		double	fps,
		Size	frameSize,
		MatOfInt	_params
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. The params parameter allows to specify extra encoder parameters encoded as pairs (paramId_1, paramValue_1, paramId_2, paramValue_2, ... .) see cv::VideoWriterProperties

◆ VideoWriter() [7/7]

OpenCVForUnity.VideoioModule.VideoWriter.VideoWriter	(	string	filename,
		int	apiPreference,
		int	fourcc,
		double	fps,
		Size	frameSize,
		MatOfInt	_params
	)

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

Member Function Documentation

◆ fromPtr()

static VideoWriter OpenCVForUnity.VideoioModule.VideoWriter.__fromPtr__ ( IntPtr addr )

static

◆ Dispose()

override void OpenCVForUnity.VideoioModule.VideoWriter.Dispose ( bool disposing )

protectedvirtual

Reimplemented from OpenCVForUnity.DisposableOpenCVObject.

◆ fourcc()

static int OpenCVForUnity.VideoioModule.VideoWriter.fourcc	(	char	c1,
		char	c2,
		char	c3,
		char	c4
	)

static

Concatenates 4 chars to a fourcc code.

Returns: a fourcc code

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

◆ get()

double OpenCVForUnity.VideoioModule.VideoWriter.get ( int propId )

Returns the specified VideoWriter property.

Parameters

propId Property identifier from cv::VideoWriterProperties (eg. cv::VIDEOWRITER_PROP_QUALITY) or one of videoio_flags_others

Returns: Value for the specified property. Value 0 is returned when querying a property that is not supported by the backend used by the VideoWriter instance.

◆ getBackendName()

string OpenCVForUnity.VideoioModule.VideoWriter.getBackendName ( )

Returns used backend API name.

Note: Stream should be opened.

◆ getNativeObjAddr()

IntPtr OpenCVForUnity.VideoioModule.VideoWriter.getNativeObjAddr ( )

◆ isOpened()

bool OpenCVForUnity.VideoioModule.VideoWriter.isOpened ( )

Returns true if video writer has been successfully initialized.

◆ open() [1/6]

bool OpenCVForUnity.VideoioModule.VideoWriter.open	(	string	filename,
		int	fourcc,
		double	fps,
		Size	frameSize,
		bool	isColor
	)

Initializes or reinitializes video writer.

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

Returns: true if video writer has been successfully initialized

The method first calls VideoWriter::release to close the already opened file.

◆ open() [2/6]

bool OpenCVForUnity.VideoioModule.VideoWriter.open	(	string	filename,
		int	fourcc,
		double	fps,
		Size	frameSize
	)

Initializes or reinitializes video writer.

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

Returns: true if video writer has been successfully initialized

The method first calls VideoWriter::release to close the already opened file.

◆ open() [3/6]

bool OpenCVForUnity.VideoioModule.VideoWriter.open	(	string	filename,
		int	apiPreference,
		int	fourcc,
		double	fps,
		Size	frameSize,
		bool	isColor
	)

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

◆ open() [4/6]

bool OpenCVForUnity.VideoioModule.VideoWriter.open	(	string	filename,
		int	apiPreference,
		int	fourcc,
		double	fps,
		Size	frameSize
	)

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

◆ open() [5/6]

bool OpenCVForUnity.VideoioModule.VideoWriter.open	(	string	filename,
		int	fourcc,
		double	fps,
		Size	frameSize,
		MatOfInt	_params
	)

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

◆ open() [6/6]

bool OpenCVForUnity.VideoioModule.VideoWriter.open	(	string	filename,
		int	apiPreference,
		int	fourcc,
		double	fps,
		Size	frameSize,
		MatOfInt	_params
	)

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

◆ release()

void OpenCVForUnity.VideoioModule.VideoWriter.release ( )

Closes the video writer.

The method is automatically called by subsequent VideoWriter::open and by the VideoWriter destructor.

◆ set()

bool OpenCVForUnity.VideoioModule.VideoWriter.set	(	int	propId,
		double	value
	)

Sets a property in the VideoWriter.

Parameters

propId	Property identifier from cv::VideoWriterProperties (eg. cv::VIDEOWRITER_PROP_QUALITY) or one of videoio_flags_others
value	Value of the property.

Returns: true if the property is supported by the backend used by the VideoWriter instance.

◆ write()

void OpenCVForUnity.VideoioModule.VideoWriter.write ( Mat image )

Writes the next video frame.

Parameters

image

The written frame. In general, color images are expected in BGR format.

The function/method writes the specified image to video file. It must have the same size as has
been specified when opening the video writer.

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

OpenCVForUnity/Assets/OpenCVForUnity/org/opencv/videoio/VideoWriter.cs

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ VideoWriter() [1/7]

◆ VideoWriter() [2/7]

◆ VideoWriter() [3/7]

◆ VideoWriter() [4/7]

◆ VideoWriter() [5/7]

◆ VideoWriter() [6/7]

◆ VideoWriter() [7/7]

Member Function Documentation

◆ __fromPtr__()

◆ Dispose()

◆ fourcc()

◆ get()

◆ getBackendName()

◆ getNativeObjAddr()

◆ isOpened()

◆ open() [1/6]

◆ open() [2/6]

◆ open() [3/6]

◆ open() [4/6]

◆ open() [5/6]

◆ open() [6/6]

◆ release()

◆ set()

◆ write()

◆ fromPtr()