AVIFCompressor Class Reference

Wrapper class to AVIF library: Handles 8 bit and alpha channels. More...

#include <AVIFCompressor.h>

Inheritance diagram for AVIFCompressor:

Public Member Functions
	AVIFCompressor (int quality)
	Constructor.
	~AVIFCompressor ()
	Destructor.
void	InitCompression (const RawTile &rawtile, unsigned int strip_height)
	Initialize strip based compression.
unsigned int	CompressStrip (unsigned char *source, unsigned char *output, unsigned int tile_height)
	Compress a strip of image data.
unsigned int	Finish (unsigned char *output)
	Finish the strip based compression and free memory.
unsigned int	Compress (RawTile &t)
	Compress an entire buffer of image data at once in one command.
unsigned int	getHeaderSize () const
	Return the WebP header size.
unsigned char *	getHeader ()
	Return a pointer to the header itself.
const char *	getMimeType () const
	Return the WebP mime type.
const char *	getSuffix () const
	Return the image filename suffix.
ImageEncoding	getImageEncoding () const
	Get compression type.
int	getQuality () const
	Get the current compression level.
void	setQuality (int quality)
	Set the compression level.
void	setCodec (unsigned int codec)
	Set codec for use during encoding - note that not all may be enabled in libavif.
Public Member Functions inherited from Compressor
	Compressor (int compressionLevel)
	Constructor.
unsigned int	getHeaderSize () const
	Return the image header size.
unsigned char *	getHeader ()
	Return a pointer to the image header itself.
int	getQuality () const
	Get the current quality level.
bool	defaultQuality () const
	Check whether we are using the default or whether user has requested a specific quality level.
void	setResolution (float x, float y, int units)
	Set the physical output resolution.
void	embedICCProfile (const bool embed)
	Embed ICC profile.
void	embedXMPMetadata (const bool embed)
	Embed XMP metadata.
void	embedExifMetadata (const bool embed)
	Embed EXIF metadata.
void	setMetadata (const std::map< const std::string, const std::string > &metadata)
	Set general metadata.
virtual void	injectMetadata (RawTile &t)
	Inject metadata into raw bitstream.

Static Public Member Functions
static avifCodecChoice	getCodecChoice (unsigned int codec)
	Static function: Convert from our option native system to libavif's codec choices.
static const char *	getCodecName (unsigned int codec)
	Static function: Get codec name from IIPImage codec option code.

Additional Inherited Members
Protected Member Functions inherited from Compressor
virtual void	writeMetadata ()
	Write metadata.
virtual void	writeResolution ()
	Write DPI.
Protected Attributes inherited from Compressor
int	Q
	Quality or compression level for all image types.
bool	default_quality
	Whether compression level is default or has been set manually.
unsigned char *	header
	Pointer to the header data for the output image.
unsigned int	header_size
	Size of the header data.
int	dpi_units
	Physical resolution units: 0 for unknown, 1 for dots/inch or 2 for dots/cm.
float	dpi_x
	Physical resolution (pixels per physical unit) for X direction.
float	dpi_y
	Physical resolution (pixels per phyisical unit) in Y direction.
std::map< const std::string, const std::string >	metadata
	Metadata.
std::string	icc
	ICC Profile.
bool	embedICC
	Whether ICC profile should be embedded.
std::string	xmp
	XMP metadata.
bool	embedXMP
	Whether XMP metadata should be embedded.
std::string	exif
	EXIF metadata.
bool	embedEXIF
	Whether EXIF metadata should be embedded.

Detailed Description

Wrapper class to AVIF library: Handles 8 bit and alpha channels.

Constructor & Destructor Documentation

AVIFCompressor()

AVIFCompressor::AVIFCompressor ( int  quality )

inline

Constructor.

Parameters

quality

WebP compression level (range 0-100)

Member Function Documentation

Compress()

unsigned int AVIFCompressor::Compress ( RawTile &  t )

virtual

Compress an entire buffer of image data at once in one command.

Compress a single tile of data.

Parameters

t	tile of image data

Returns

size of compressed data

Reimplemented from Compressor.

References RawTile::bpc, RawTile::capacity, RawTile::channels, RawTile::compressionType, RawTile::data, RawTile::dataLength, RawTile::height, RawTile::memoryManaged, Compressor::Q, RawTile::quality, RawTile::triplicate(), and RawTile::width.

Referenced by InitCompression().

CompressStrip()

unsigned int AVIFCompressor::CompressStrip ( unsigned char *  source, unsigned char *  output, unsigned int  tile_height  )

virtual

Compress a strip of image data.

libwebp cannot handle line or region-based encoding, so simulate strip-based output using byte chunks

Parameters

source	source image data
tile_height	pixel height of the tile we are compressing
output	output_buffer

Returns

size of compressed strip

Reimplemented from Compressor.

References RawTile::data, RawTile::dataLength, and RawTile::height.

Finish()

unsigned int AVIFCompressor::Finish ( unsigned char *  output )

virtual

Finish the strip based compression and free memory.

Parameters

output

Output buffer

Returns

size of output generated

Reimplemented from Compressor.

References RawTile::data, and RawTile::dataLength.

getCodecChoice()

static avifCodecChoice AVIFCompressor::getCodecChoice ( unsigned int  codec )

inlinestatic

Static function: Convert from our option native system to libavif's codec choices.

Parameters

codec

IIPImage's codec option code (0=auto,1=aom,2=rav1e,3=svt)

Returns

libavif codec choice enum

Referenced by getCodecName(), and setCodec().

getCodecName()

static const char * AVIFCompressor::getCodecName ( unsigned int  codec )

inlinestatic

Static function: Get codec name from IIPImage codec option code.

Parameters

codec

IIPImage's codec option code (0=auto,1=aom,2=rav1e,3=svt)

Returns

code name

References getCodecChoice().

getImageEncoding()

ImageEncoding AVIFCompressor::getImageEncoding ( ) const

inlinevirtual

Get compression type.

Reimplemented from Compressor.

getMimeType()

const char * AVIFCompressor::getMimeType ( ) const

inlinevirtual

Return the WebP mime type.

Reimplemented from Compressor.

getQuality()

int AVIFCompressor::getQuality ( ) const

inline

Get the current compression level.

Returns

compresson level

References Compressor::Q.

getSuffix()

const char * AVIFCompressor::getSuffix ( ) const

inlinevirtual

Return the image filename suffix.

Reimplemented from Compressor.

InitCompression()

void AVIFCompressor::InitCompression ( const RawTile &  rawtile, unsigned int  strip_height  )

virtual

Initialize strip based compression.

Initialize chunk-based encoding for the CVT handler.

For strip based encoding, we need to first initialize with InitCompression, then compress a single strip at a time using CompressStrip and finally clean up using Finish

Parameters

rawtile	RawTile object containing the image to be compressed
strip_height	height in pixels of the strip we want to compress

Reimplemented from Compressor.

References RawTile::bpc, RawTile::capacity, RawTile::channels, Compress(), RawTile::data, RawTile::dataLength, RawTile::height, RawTile::memoryManaged, and RawTile::width.

setCodec()

void AVIFCompressor::setCodec ( unsigned int  codec )

inline

Set codec for use during encoding - note that not all may be enabled in libavif.

Parameters

codec

IIPImage's codec option code (0=auto,1=aom,2=rav1e,3=svt)

References getCodecChoice().

setQuality()

void AVIFCompressor::setQuality ( int  quality )

inlinevirtual

Set the compression level.

Parameters

quality

compression level: 0-100 with (0 = highest compression). -1 = lossless

Reimplemented from Compressor.

References Compressor::Q.

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

• AVIFCompressor.h
• AVIFCompressor.cc