heif

Documentation

Overview

Package heif reads HEIF containers, as found in Apple HEIC/HEVC images. This package does not decode images; it only reads the metadata.

This package is a work in progress and makes no API compatibility promises.

Index

• Variables
• type BoxMeta
  • func (m *BoxMeta) EXIFItemID() uint32
• type File
  • func Open(f io.ReaderAt) *File
  • func (f *File) EXIF() ([]byte, error)
  • func (f *File) ItemByID(id uint32) (*Item, error)
  • func (f *File) PrimaryItem() (*Item, error)
• type Item
  • func (it *Item) Rotations() int
  • func (it *Item) SpatialExtents() (width, height int, ok bool)
  • func (it *Item) VisualDimensions() (width, height int, ok bool)

Variables

var ErrNoEXIF = errors.New("heif: no EXIF found")

ErrNoEXIF is returned by File.EXIF when a file does not contain an EXIF item.

var ErrUnknownItem = errors.New("heif: unknown item")

ErrUnknownItem is returned by File.ItemByID for unknown items.

Types

type BoxMeta

type BoxMeta struct {
	FileType     *bmff.FileTypeBox
	Handler      *bmff.HandlerBox
	PrimaryItem  *bmff.PrimaryItemBox
	ItemInfo     *bmff.ItemInfoBox
	Properties   *bmff.ItemPropertiesBox
	ItemLocation *bmff.ItemLocationBox
}

BoxMeta contains the low-level BMFF metadata boxes.

func (*BoxMeta) EXIFItemID

func (m *BoxMeta) EXIFItemID() uint32

EXIFItemID returns the item ID of the EXIF part, or 0 if not found.

type File

type File struct {
	// contains filtered or unexported fields
}

File represents a HEIF file.

Methods on File should not be called concurrently.

func Open

func Open(f io.ReaderAt) *File

Open returns a handle to access a HEIF file.

func (*File) EXIF

func (f *File) EXIF() ([]byte, error)

EXIF returns the raw EXIF data from the file. The error is ErrNoEXIF if the file did not contain EXIF.

The raw EXIF data can be parsed by the github.com/rwcarlsen/goexif/exif package's Decode function.

func (*File) ItemByID

func (f *File) ItemByID(id uint32) (*Item, error)

ItemByID by returns the file's Item of a given ID. If the ID is known, the returned error is ErrUnknownItem.

func (*File) PrimaryItem

func (f *File) PrimaryItem() (*Item, error)

PrimaryItem returns the HEIF file's primary item.

type Item

type Item struct {
	ID         uint32
	Info       *bmff.ItemInfoEntry
	Location   *bmff.ItemLocationBoxEntry // location in file
	Properties []bmff.Box
	// contains filtered or unexported fields
}

Item represents an item in a HEIF file.

func (*Item) Rotations

func (it *Item) Rotations() int

Rotations returns the number of 90 degree rotations counter-clockwise that this image should be rendered at, in the range [0,3].

func (*Item) SpatialExtents

func (it *Item) SpatialExtents() (width, height int, ok bool)

SpatialExtents returns the item's spatial extents property values, if present, not correcting from any camera rotation metadata.

func (*Item) VisualDimensions

func (it *Item) VisualDimensions() (width, height int, ok bool)

VisualDimensions returns the item's width and height after correcting for any rotations.