Documentation
¶
Overview ¶
Package bmff reads ISO BMFF boxes, as used by HEIF, etc.
This is not so much as a generic BMFF reader as it is a BMFF reader as needed by HEIF, though that may change in time. For now, only boxes necessary for the go4.org/media/heif package have explicit parsers.
This package makes no API compatibility promises; it exists primarily for use by the go4.org/media/heif package.
Index ¶
- Variables
- type Box
- type BoxType
- type DataInformationBox
- type DataReferenceBox
- type FileTypeBox
- type FullBox
- type HandlerBox
- type ImageRotation
- type ImageSpatialExtentsProperty
- type ItemInfoBox
- type ItemInfoEntry
- type ItemLocationBox
- type ItemLocationBoxEntry
- type ItemPropertiesBox
- type ItemProperty
- type ItemPropertyAssociation
- type ItemPropertyAssociationItem
- type ItemPropertyContainerBox
- type MetaBox
- type OffsetLength
- type PrimaryItemBox
- type Reader
Constants ¶
This section is empty.
Variables ¶
var ( TypeFtyp = BoxType{'f', 't', 'y', 'p'} TypeMeta = BoxType{'m', 'e', 't', 'a'} )
Common box types.
var ErrUnknownBox = errors.New("heif: unknown box")
ErrUnknownBox is returned by Box.Parse for unrecognized box types.
Functions ¶
This section is empty.
Types ¶
type Box ¶
type Box interface {
Size() int64 // 0 means unknown (will read to end of file)
Type() BoxType
// Parses parses the box, populating the fields
// in the returned concrete type.
//
// If Parse has already been called, Parse returns nil.
// If the box type is unknown, the returned error is ErrUnknownBox
// and it's guaranteed that no bytes have been read from the box.
Parse() (Box, error)
// Body returns the inner bytes of the box, ignoring the header.
// The body may start with the 4 byte header of a "Full Box" if the
// box's type derives from a full box. Most users will use Parse
// instead.
// Body will return a new reader at the beginning of the box if the
// outer box has already been parsed.
Body() io.Reader
}
Box represents a BMFF box.
type DataInformationBox ¶
type DataInformationBox struct {
Children []Box
// contains filtered or unexported fields
}
a "dinf" box
type DataReferenceBox ¶
a "dref" box.
type FileTypeBox ¶
type FullBox ¶
type HandlerBox ¶
type HandlerBox struct {
FullBox
HandlerType string // always 4 bytes; usually "pict" for iOS Camera images
Name string
}
a "hdlr" box.
type ImageRotation ¶
type ImageRotation struct {
Angle uint8 // 1 means 90 degrees counter-clockwise, 2 means 180 counter-clockwise
// contains filtered or unexported fields
}
ImageRotation is a HEIF "irot" rotation property.
type ImageSpatialExtentsProperty ¶
type ItemInfoBox ¶
type ItemInfoBox struct {
FullBox
Count uint16
ItemInfos []*ItemInfoEntry
}
ItemInfoBox represents an "iinf" box.
type ItemInfoEntry ¶
type ItemInfoEntry struct {
FullBox
ItemID uint16
ProtectionIndex uint16
ItemType string // always 4 bytes
Name string
// If Type == "mime":
ContentType string
ContentEncoding string
// If Type == "uri ":
ItemURIType string
}
ItemInfoEntry represents an "infe" box.
TODO: currently only parses Version 2 boxes.
type ItemLocationBox ¶
type ItemLocationBox struct {
FullBox
ItemCount uint16
Items []ItemLocationBoxEntry
// contains filtered or unexported fields
}
box "iloc"
type ItemLocationBoxEntry ¶
type ItemLocationBoxEntry struct {
ItemID uint16
ConstructionMethod uint8 // actually uint4
DataReferenceIndex uint16
BaseOffset uint64 // uint32 or uint64, depending on encoding
ExtentCount uint16
Extents []OffsetLength
}
not a box
type ItemPropertiesBox ¶
type ItemPropertiesBox struct {
PropertyContainer *ItemPropertyContainerBox
Associations []*ItemPropertyAssociation // at least 1
// contains filtered or unexported fields
}
HEIF: iprp
type ItemPropertyAssociation ¶
type ItemPropertyAssociation struct {
FullBox
EntryCount uint32
Entries []ItemPropertyAssociationItem
}
type ItemPropertyAssociationItem ¶
type ItemPropertyAssociationItem struct {
ItemID uint32
AssociationsCount int // as declared
Associations []ItemProperty // as parsed
}
not a box
type ItemPropertyContainerBox ¶
type ItemPropertyContainerBox struct {
Properties []Box // of ItemProperty or ItemFullProperty
// contains filtered or unexported fields
}
HEIF: ipco
type OffsetLength ¶
type OffsetLength struct {
Offset, Length uint64
}
type PrimaryItemBox ¶
"pitm" box
type Reader ¶
type Reader struct {
// contains filtered or unexported fields
}
func (*Reader) ReadAndParseBox ¶
ReadAndParseBox wraps the ReadBox method, ensuring that the read box is of type typ and parses successfully. It returns the parsed box.
Source Files