openshot::ImageWriter Class Reference

This class uses the ImageMagick library to write image files (including animated GIFs) More...

#include <ImageWriter.h>

Inheritance diagram for openshot::ImageWriter:

Collaboration diagram for openshot::ImageWriter:

Public Member Functions
void	Close ()
	Close the writer and encode/output final image to the disk. This is a requirement of ImageMagick, which writes all frames of a multi-frame image at one time. More...
int	GetCacheSize ()
	Get the cache size. More...
	ImageWriter (std::string path)
	Constructor for ImageWriter. Throws one of the following exceptions. More...
bool	IsOpen ()
	Determine if writer is open or closed. More...
void	Open ()
	Open writer. More...
void	SetCacheSize (int new_size)
	Set the cache size (number of frames to queue before writing) More...
void	SetVideoOptions (std::string format, Fraction fps, int width, int height, int quality, int loops, bool combine)
	Set the video export options. More...
void	WriteFrame (ReaderBase *reader, int64_t start, int64_t length)
	Write a block of frames from a reader. More...
void	WriteFrame (std::shared_ptr< Frame > frame)
	Add a frame to the stack waiting to be encoded. More...
Public Member Functions inherited from openshot::WriterBase
void	CopyReaderInfo (openshot::ReaderBase *reader)
	This method copy's the info struct of a reader, and sets the writer with the same info. More...
void	DisplayInfo (std::ostream *out=&std::cout)
	Display file information in the standard output stream (stdout) More...
std::string	Json () const
	Generate JSON string of this object. More...
Json::Value	JsonValue () const
	Generate Json::Value for this object. More...
void	SetJson (const std::string value)
	Load JSON string into this object. More...
void	SetJsonValue (const Json::Value root)
	Load Json::Value into this object. More...
virtual void	WriteFrame (std::shared_ptr< openshot::Frame > frame)=0
	This method is required for all derived classes of WriterBase. Write a Frame to the video file. More...
	WriterBase ()
	Constructor for WriterBase class, many things are initialized here. More...
virtual	~WriterBase ()=default

Additional Inherited Members
Public Attributes inherited from openshot::WriterBase
WriterInfo	info
	Information about the current media file. More...

Detailed Description

This class uses the ImageMagick library to write image files (including animated GIFs)

All image formats supported by ImageMagick are supported by this class.

// Create a reader for a video
FFmpegReader r("MyAwesomeVideo.webm");
r.Open(); // Open the reader
 
// Create a writer (which will create an animated GIF file)
ImageWriter w("/home/jonathan/NewAnimation.gif");
 
// Set the image output settings (format, fps, width, height, quality, loops, combine)
w.SetVideoOptions("GIF", r.info.fps, r.info.width, r.info.height, 70, 1, true);
 
// Open the writer
w.Open();
 
// Write the 1st 30 frames from the reader
w.WriteFrame(&r, 1, 30);
 
// Close the reader & writer
w.Close();
r.Close();

Definition at line 59 of file ImageWriter.h.

Constructor & Destructor Documentation

ImageWriter()

ImageWriter::ImageWriter

(

std::string

path

)

Constructor for ImageWriter. Throws one of the following exceptions.

Parameters

path	The path of the file you want to create

Definition at line 27 of file ImageWriter.cpp.

Member Function Documentation

Close()

void ImageWriter::Close

(

)

Close the writer and encode/output final image to the disk. This is a requirement of ImageMagick, which writes all frames of a multi-frame image at one time.

Definition at line 140 of file ImageWriter.cpp.

GetCacheSize()

int openshot::ImageWriter::GetCacheSize ( )

inline

Get the cache size.

Definition at line 84 of file ImageWriter.h.

IsOpen()

bool openshot::ImageWriter::IsOpen ( )

inlinevirtual

Determine if writer is open or closed.

Implements openshot::WriterBase.

Definition at line 87 of file ImageWriter.h.

Open()

void ImageWriter::Open ( )

virtual

Open writer.

Implements openshot::WriterBase.

Definition at line 79 of file ImageWriter.cpp.

SetCacheSize()

void openshot::ImageWriter::SetCacheSize ( int  new_size )

inline

Set the cache size (number of frames to queue before writing)

Parameters

new_size

Number of frames to queue before writing

Definition at line 94 of file ImageWriter.h.

SetVideoOptions()

void ImageWriter::SetVideoOptions	(	std::string	format,
		Fraction	fps,
		int	width,
		int	height,
		int	quality,
		int	loops,
		bool	combine
	)

Set the video export options.

Parameters

format	The image format (such as GIF)
fps	Frames per second of the image (used on certain multi-frame image formats, such as GIF)
width	Width in pixels of image
height	Height in pixels of image
quality	Quality of image (0 to 100, 70 is default)
loops	Number of times to repeat the image (used on certain multi-frame image formats, such as GIF)
combine	Combine frames into a single image (if possible), or save each frame as its own image

Definition at line 36 of file ImageWriter.cpp.

WriteFrame() [1/2]

void ImageWriter::WriteFrame ( ReaderBase *  reader, int64_t  start, int64_t  length  )

virtual

Write a block of frames from a reader.

Parameters

reader	A openshot::ReaderBase object which will provide frames to be written
start	The starting frame number of the reader
length	The number of frames to write

Implements openshot::WriterBase.

Definition at line 121 of file ImageWriter.cpp.

WriteFrame() [2/2]

void ImageWriter::WriteFrame

(

std::shared_ptr< Frame >

frame

)

Add a frame to the stack waiting to be encoded.

Parameters

frame

The openshot::Frame object to write to this image

Definition at line 85 of file ImageWriter.cpp.

Referenced by WriteFrame().

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

• ImageWriter.h
• ImageWriter.cpp