Implementation of TagParser::Tag for the MP4 container. More...

#include <mp4tag.h>

Inheritance diagram for TagParser::Mp4Tag:

Collaboration diagram for TagParser::Mp4Tag:

Public Member Functions
	Mp4Tag ()
	Constructs a new tag.

bool	canEncodingBeUsed (TagTextEncoding encoding) const override
	Returns an indication whether the specified encoding can be used to provide string values for the tag.

bool	supportsField (KnownField field) const override
	Returns an indication whether the specified field is supported by the tag.

const TagValue &	value (KnownField value) const override
	Returns the value of the specified field.

std::vector< const TagValue * >	values (KnownField field) const override
	Returns the values of the specified field.

const TagValue &	value (std::string_view mean, std::string_view name) const
	Returns the value of the field with the specified mean and name attributes.

bool	setValue (KnownField field, const TagValue &value) override
	Assigns the given value to the specified field.

bool	setValues (KnownField field, const std::vector< TagValue > &values) override
	Assigns the given values to the field with the specified id.

bool	setValue (std::string_view mean, std::string_view name, const TagValue &value)
	Assigns the given value to the field with the specified mean and name attributes.

bool	hasField (KnownField value) const override
	Returns an indication whether the specified field is present.

bool	supportsMultipleValues (KnownField) const override
	Returns false for all fields (for now).

void	parse (Mp4Atom &metaAtom, Diagnostics &diag)
	Parses tag information from the specified metaAtom.

Mp4TagMaker	prepareMaking (Diagnostics &diag)
	Prepares making.

void	make (std::ostream &stream, Diagnostics &diag)
	Writes tag information to the specified stream.

Public Member Functions inherited from TagParser::FieldMapBasedTag< Mp4Tag >
	FieldMapBasedTag ()
	Constructs a new FieldMapBasedTag.

TagType	type () const
	Returns the type of the tag as TagParser::TagType.

std::string_view	typeName () const
	Returns the type name of the tag as C-style string.

TagTextEncoding	proposedTextEncoding () const
	Returns the proposed text encoding.

const TagValue &	value (const IdentifierType &id) const
	Returns the value of the field with the specified id.

std::vector< const TagValue * >	values (const IdentifierType &id) const
	Returns the values of the field with the specified id.

bool	setValue (const IdentifierType &id, const TagValue &value)
	Assigns the given value to the field with the specified id.

bool	setValues (const IdentifierType &id, const std::vector< TagValue > &values)
	Assigns the given values to the field with the specified id.

bool	hasField (const IdentifierType &id) const
	Returns an indication whether the field with the specified id is present.

void	removeAllFields ()
	Removes all fields from the tag.

const std::multimap< IdentifierType, FieldType, Compare > &	fields () const
	Returns the fields of the tag by providing direct access to the field map of the tag.

std::multimap< IdentifierType, FieldType, Compare > &	fields ()
	Returns the fields of the tag by providing direct access to the field map of the tag.

std::size_t	fieldCount () const
	Returns the number of present fields.

IdentifierType	fieldId (KnownField value) const
	Returns the ID for the specified field.

KnownField	knownField (const IdentifierType &id) const
	Returns the field for the specified ID.

TagDataType	proposedDataType (const IdentifierType &id) const
	Returns the proposed data type for the field with the specified id.

virtual TagDataType	proposedDataType (KnownField field) const
	Returns the proposed data type for the specified field as TagDataType.

std::size_t	insertFields (const FieldMapBasedTag< Mp4Tag > &from, bool overwrite)
	Inserts all fields from another tag of the same field type and compare function.

std::size_t	insertValues (const Tag &from, bool overwrite)
	Inserts all compatible values from another Tag.

void	ensureTextValuesAreProperlyEncoded ()
	Ensures the encoding of all assigned text values is supported by the tag by converting the character set if necessary.

Public Member Functions inherited from TagParser::Tag
virtual	~Tag ()
	Destroys the Tag.

std::string	toString () const
	Returns a string representation of the tag.

const std::string &	version () const
	Returns the version of the tag as std::string.

std::uint64_t	size () const
	Returns the size the tag within the file it is parsed from in bytes.

virtual bool	supportsTarget () const
	Returns an indication whether a target is supported by the tag.

const TagTarget &	target () const

TagTarget &	target ()
	Returns the target of tag.

void	setTarget (const TagTarget &target)
	Sets the target of tag.

virtual TagTargetLevel	targetLevel () const
	Returns the name of the current tag target level.

std::string_view	targetLevelName () const
	Returns the name of the current target level.

bool	isTargetingLevel (TagTargetLevel tagTargetLevel) const
	Returns whether the tag is targeting the specified tagTargetLevel.

std::string	targetString () const
	Returns the string representation for the assigned tag target.

virtual bool	supportsDescription (KnownField field) const
	Returns an indications whether the specified field supports descriptions.

virtual bool	supportsMimeType (KnownField field) const
	Returns an indications whether the specified field supports mime types.

Static Public Attributes
static constexpr TagType	tagType = TagType::Mp4Tag

static constexpr std::string_view	tagName = "MP4/iTunes tag"

static constexpr TagTextEncoding	defaultTextEncoding = TagTextEncoding::Utf8

Protected Member Functions
IdentifierType	internallyGetFieldId (KnownField field) const

KnownField	internallyGetKnownField (const IdentifierType &id) const

void	internallyGetValuesFromField (const FieldType &field, std::vector< const TagValue * > &values) const
	Adds values from additional data atoms as well.

Protected Member Functions inherited from TagParser::FieldMapBasedTag< Mp4Tag >
const TagValue &	internallyGetValue (const IdentifierType &id) const
	Default implementation for value().

void	internallyGetValuesFromField (const FieldType &field, std::vector< const TagValue * > &values) const
	Default way to gather values from a field in internallyGetValues().

std::vector< const TagValue * >	internallyGetValues (const IdentifierType &id) const
	Default implementation for values().

bool	internallySetValue (const IdentifierType &id, const TagValue &value)
	Default implementation for setValue().

bool	internallySetValues (const IdentifierType &id, const std::vector< TagValue > &values)
	Default implementation for setValues().

bool	internallyHasField (const IdentifierType &id) const
	Default implementation for hasField().

TagDataType	internallyGetProposedDataType (const IdentifierType &id) const
	Default implementation for proposedDataType().

Protected Member Functions inherited from TagParser::Tag
	Tag ()
	Constructs a new Tag.

Friends
class	FieldMapBasedTag< Mp4Tag >

Additional Inherited Members
Public Types inherited from TagParser::FieldMapBasedTag< Mp4Tag >
using	FieldType = typename FieldMapBasedTagTraits< Mp4Tag >::FieldType

using	IdentifierType = typename FieldMapBasedTagTraits< Mp4Tag >::FieldType::IdentifierType

using	Compare = typename FieldMapBasedTagTraits< Mp4Tag >::Compare

Protected Types inherited from TagParser::FieldMapBasedTag< Mp4Tag >
using	CRTPBase = FieldMapBasedTag< Mp4Tag >

Protected Attributes inherited from TagParser::Tag
std::string	m_version

std::uint64_t	m_size

std::unique_ptr< TagPrivate >	m_p

TagTarget	m_target

Detailed Description

Implementation of TagParser::Tag for the MP4 container.

Definition at line 97 of file mp4tag.h.

Constructor & Destructor Documentation

◆ Mp4Tag()

TagParser::Mp4Tag::Mp4Tag ( )

inline

Constructs a new tag.

Definition at line 136 of file mp4tag.h.

Member Function Documentation

◆ canEncodingBeUsed()

bool TagParser::Mp4Tag::canEncodingBeUsed ( TagTextEncoding encoding ) const

overridevirtual

Returns an indication whether the specified encoding can be used to provide string values for the tag.

Only the proposedTextEncoding() is accepted by default. This might be overwritten when subclassing.

The tag class and its subclasses do not perform any conversions. You have to provide all string values using an encoding which is appropriate for the specific tag type. This method is meant to determine if a particular encoding can be used.

See also: canEncodingBeUsed()

Reimplemented from TagParser::Tag.

Definition at line 47 of file mp4tag.cpp.

◆ hasField()

bool TagParser::Mp4Tag::hasField ( KnownField field ) const

overridevirtual

Returns an indication whether the specified field is present.

See also: value(), setValue()

Reimplemented from TagParser::FieldMapBasedTag< Mp4Tag >.

Definition at line 349 of file mp4tag.cpp.

◆ internallyGetFieldId()

Mp4Tag::IdentifierType TagParser::Mp4Tag::internallyGetFieldId ( KnownField field ) const

protected

Definition at line 119 of file mp4tag.cpp.

◆ internallyGetKnownField()

KnownField TagParser::Mp4Tag::internallyGetKnownField ( const IdentifierType & id ) const

protected

Definition at line 187 of file mp4tag.cpp.

◆ internallyGetValuesFromField()

void TagParser::Mp4Tag::internallyGetValuesFromField	(	const FieldType &	field,
		std::vector< const TagValue * > &	values
	)		const

protected

Adds values from additional data atoms as well.

Definition at line 259 of file mp4tag.cpp.

◆ make()

void TagParser::Mp4Tag::make	(	std::ostream &	stream,
		Diagnostics &	diag
	)

Writes tag information to the specified stream.

Exceptions

Throws	std::ios_base::failure when an IO error occurs.
Throws	TagParser::Failure or a derived exception when a making error occurs.

Definition at line 443 of file mp4tag.cpp.

◆ parse()

void TagParser::Mp4Tag::parse	(	Mp4Atom &	metaAtom,
		Diagnostics &	diag
	)

Parses tag information from the specified metaAtom.

Exceptions

Throws	std::ios_base::failure when an IO error occurs.
Throws	TagParser::Failure or a derived exception when a parsing error occurs.

Definition at line 366 of file mp4tag.cpp.

◆ prepareMaking()

Mp4TagMaker TagParser::Mp4Tag::prepareMaking ( Diagnostics & diag )

Prepares making.

Returns: Returns a Mp4TagMaker object which can be used to actually make the tag.

Remarks: The tag must NOT be mutated after making is prepared when it is intended to actually make the tag using the make method of the returned object.

Exceptions

Throws TagParser::Failure or a derived exception when a making error occurs.

This method might be useful when it is necessary to know the size of the tag before making it.

See also: make()

Definition at line 432 of file mp4tag.cpp.

◆ setValue() [1/2]

bool TagParser::Mp4Tag::setValue	(	KnownField	field,
		const TagValue &	value
	)

overridevirtual

Assigns the given value to the specified field.

Remarks

If an empty value is given, the field will be be removed.
Some tags support more than just one value per field. This method will only alter the first value.

See also: value(), hasField()

Reimplemented from TagParser::FieldMapBasedTag< Mp4Tag >.

Definition at line 271 of file mp4tag.cpp.

◆ setValue() [2/2]

bool TagParser::Mp4Tag::setValue	(	std::string_view	mean,
		std::string_view	name,
		const TagValue &	value
	)

Assigns the given value to the field with the specified mean and name attributes.

Remarks

If there are multiple fields with specified mean and name only the first will be altered.
If no field is present, a new one will be created.
If value is empty, the field will be removed.

Definition at line 336 of file mp4tag.cpp.

◆ setValues()

bool TagParser::Mp4Tag::setValues	(	KnownField	field,
		const std::vector< TagValue > &	values
	)

overridevirtual

Assigns the given values to the field with the specified id.

Remarks: There might me more than one value assigned to a field. Whereas setValue() only alters the first value, this method will replace all currently assigned values with the specified values.

See also: Tag::setValues()

Reimplemented from TagParser::FieldMapBasedTag< Mp4Tag >.

Definition at line 295 of file mp4tag.cpp.

◆ supportsField()

bool TagParser::Mp4Tag::supportsField ( KnownField field ) const

inlineoverridevirtual

Returns an indication whether the specified field is supported by the tag.

Reimplemented from TagParser::FieldMapBasedTag< Mp4Tag >.

Definition at line 140 of file mp4tag.h.

◆ supportsMultipleValues()

bool TagParser::Mp4Tag::supportsMultipleValues ( KnownField ) const

inlineoverridevirtual

Returns false for all fields (for now).

Remarks: Not sure whether iTunes-style MP4 tags allow this. Let's return false for now.

Todo:: Do some research whether it is supported or not.

Reimplemented from TagParser::Tag.

Definition at line 155 of file mp4tag.h.

◆ value() [1/2]

const TagValue & TagParser::Mp4Tag::value ( KnownField field ) const

overridevirtual

Returns the value of the specified field.

Remarks

If the specified field is not present an empty TagValue will be returned.
Some tags support more than just one value per field. If there are multiple values this method just returns the first one.

See also: setValue(), hasField()

Reimplemented from TagParser::FieldMapBasedTag< Mp4Tag >.

Definition at line 59 of file mp4tag.cpp.

◆ value() [2/2]

const TagValue & TagParser::Mp4Tag::value	(	std::string_view	mean,
		std::string_view	name
	)		const

Returns the value of the field with the specified mean and name attributes.

Remarks

If there are multiple fields with specified mean and name only the first value will be returned.

Definition at line 108 of file mp4tag.cpp.

◆ values()

std::vector< const TagValue * > TagParser::Mp4Tag::values ( KnownField field ) const

overridevirtual

Returns the values of the specified field.

Remarks

There might me more than one value assigned to a field. Whereas value() returns only the first value, this method returns all values.
However, the default implementation just returns the first value assuming multiple values per field are not supported by the tag.

Reimplemented from TagParser::FieldMapBasedTag< Mp4Tag >.

Definition at line 85 of file mp4tag.cpp.

Friends And Related Symbol Documentation

◆ FieldMapBasedTag< Mp4Tag >

friend class FieldMapBasedTag< Mp4Tag >

friend

Definition at line 69 of file mp4tag.h.

Member Data Documentation

◆ defaultTextEncoding

constexpr TagTextEncoding TagParser::Mp4Tag::defaultTextEncoding = TagTextEncoding::Utf8

staticconstexpr

Definition at line 105 of file mp4tag.h.

◆ tagName

constexpr std::string_view TagParser::Mp4Tag::tagName = "MP4/iTunes tag"

staticconstexpr

Definition at line 104 of file mp4tag.h.

◆ tagType

constexpr TagType TagParser::Mp4Tag::tagType = TagType::Mp4Tag

staticconstexpr

Definition at line 103 of file mp4tag.h.

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

mp4/mp4tag.h
mp4/mp4tag.cpp

Public Member Functions

Static Public Attributes

Protected Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Mp4Tag()

Member Function Documentation

◆ canEncodingBeUsed()

◆ hasField()

◆ internallyGetFieldId()

◆ internallyGetKnownField()

◆ internallyGetValuesFromField()

◆ make()

◆ parse()

◆ prepareMaking()

◆ setValue() [1/2]

◆ setValue() [2/2]

◆ setValues()

◆ supportsField()

◆ supportsMultipleValues()

◆ value() [1/2]

◆ value() [2/2]

◆ values()

Friends And Related Symbol Documentation

◆ FieldMapBasedTag< Mp4Tag >

Member Data Documentation

◆ defaultTextEncoding

◆ tagName

◆ tagType