Metadata Class Reference

Key-value metadata container using typed Variant values. More...

#include <metadata.h>

Public Types
enum	ID {   Invalid , Timecode , Gamma , Title ,   Copyright , Software , Artist , Comment ,   Date , Album , License , TrackNumber ,   Genre , EnableBWF , Description , Originator ,   OriginatorReference , OriginationDateTime , FrameRate , UMID ,   CodingHistory , CompressionLevel , EnableVBR , VBRQuality ,   CompressedSize , EndOfStream }
using	Ptr = SharedPtr< Metadata >
	Shared pointer type for Metadata.

Public Member Functions
	Metadata ()=default
	Constructs an empty Metadata object.
template<typename T >
void	set (ID id, const T &value)
	Sets a metadata value for the given ID.
const Variant &	get (ID id) const
	Returns the Variant value for the given ID.
bool	contains (ID id) const
	Returns true if the given ID has been set.
void	remove (ID id)
	Removes the entry for the given ID.
void	clear ()
	Removes all metadata entries.
size_t	size () const
	Returns the number of metadata entries.
bool	isEmpty () const
	Returns true if no metadata entries are stored.
template<typename Func >
void	forEach (Func &&func) const
	Iterates over all metadata entries, invoking a callback for each.
StringList	dump () const
	Returns a human-readable dump of all metadata entries.
bool	operator== (const Metadata &other) const
	Returns true if both Metadata objects contain the same entries.
JsonObject	toJson () const
	Serializes this Metadata to a JSON object.

Static Public Member Functions
static const String &	idToString (ID id)
	Converts a metadata ID to its string name.
static ID	stringToID (const String &val)
	Converts a string name to a metadata ID.
static Metadata	fromJson (const JsonObject &json, Error *err=nullptr)
	Deserializes a Metadata object from a JSON object.

Detailed Description

Key-value metadata container using typed Variant values.

Stores metadata entries keyed by a well-known ID enum. Each value is stored as a Variant, supporting types such as String, int, double, bool, Timecode, and Rational. Supports JSON serialization

Example

Metadata meta;
meta.set(Metadata::Title, String("My Video"));
meta.set(Metadata::FrameRate, Rational<int>(24, 1));
 
String title = meta.value(Metadata::Title).get<String>();
bool has = meta.isSet(Metadata::Copyright);  // false

and deserialization. When shared ownership is needed, use Metadata::Ptr.

Member Enumeration Documentation

ID

enum Metadata::ID

Enumerator
CompressedSize	Internal: allocation hint for compressed pixel formats. Use Image::compressedSize() instead.
EndOfStream	Signals end-of-stream to downstream nodes.

Member Function Documentation

contains()

bool Metadata::contains ( ID  id ) const

inline

Returns true if the given ID has been set.

Parameters

id	The metadata key.

Returns

true if the key exists.

dump()

StringList Metadata::dump

(

)

const

Returns a human-readable dump of all metadata entries.

Returns

A StringList with one entry per metadata key-value pair.

forEach()

template<typename Func >

void Metadata::forEach ( Func &&  func ) const

inline

Iterates over all metadata entries, invoking a callback for each.

Template Parameters

Func	Callable type with signature void(ID, const Variant &).

Parameters

func	The callback to invoke for each entry.

fromJson()

static Metadata Metadata::fromJson ( const JsonObject &  json, Error *  err = nullptr  )

static

Deserializes a Metadata object from a JSON object.

Parameters

json	The source JSON object.
err	Optional error output.

Returns

The deserialized Metadata.

get()

const Variant & Metadata::get ( ID  id ) const

inline

Returns the Variant value for the given ID.

Parameters

id	The metadata key.

Returns

A const reference to the Variant value.

idToString()

static const String & Metadata::idToString ( ID  id )

static

Converts a metadata ID to its string name.

Parameters

id	The metadata ID.

Returns

A const reference to the name string.

isEmpty()

bool Metadata::isEmpty ( ) const

inline

Returns true if no metadata entries are stored.

Returns

true if empty.

operator==()

bool Metadata::operator== ( const Metadata &  other ) const

inline

Returns true if both Metadata objects contain the same entries.

Parameters

other

The Metadata to compare against.

Returns

true if equal.

remove()

void Metadata::remove ( ID  id )

inline

Removes the entry for the given ID.

Parameters

id	The metadata key to remove.

set()

template<typename T >

void Metadata::set ( ID  id, const T &  value  )

inline

Sets a metadata value for the given ID.

Template Parameters

T	The value type.

Parameters

id	The metadata key.
value	The value to store.

size()

size_t Metadata::size ( ) const

inline

Returns the number of metadata entries.

Returns

The entry count.

stringToID()

static ID Metadata::stringToID ( const String &  val )

static

Converts a string name to a metadata ID.

Parameters

val	The name string.

Returns

The corresponding ID, or Invalid if not found.

toJson()

JsonObject Metadata::toJson ( ) const

inline

Serializes this Metadata to a JSON object.

Returns

A JsonObject containing all metadata entries.

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

• include/promeki/core/metadata.h