VideoMetaData Class Reference

Reads video metadata tags using FFmpeg Raw values for Orientation & Date are read quickly via FFmpeg API. More...

Inheritance diagram for VideoMetaData:

Collaboration diagram for VideoMetaData:

Public Member Functions
	VideoMetaData (const QString &filePath)
	Constructor. Opens best video stream from video. More...
	~VideoMetaData () override
	Destructor. Closes file. More...
bool	IsValid () override
QStringList	GetAllTags () override
	Reads relevant video metadata by running mythffprobe. More...
int	GetOrientation (bool *exists=nullptr) override
	Read FFmpeg video orientation tag. More...
QDateTime	GetOriginalDateTime (bool *exists=nullptr) override
	Read video datestamp. More...
QString	GetComment (bool *exists=nullptr) override
	Read Video comment from metadata. More...
Public Member Functions inherited from ImageMetaData
virtual	~ImageMetaData ()=default
virtual bool	IsValid ()=0
virtual QStringList	GetAllTags ()=0
virtual int	GetOrientation (bool *exists=nullptr)=0
virtual QDateTime	GetOriginalDateTime (bool *exists=nullptr)=0
virtual QString	GetComment (bool *exists=nullptr)=0

Protected Member Functions
QString	GetTag (const QString &key, bool *exists=nullptr)
	Read a single video tag. More...
Protected Member Functions inherited from ImageMetaData
	ImageMetaData (QString filePath)

Protected Attributes
AVFormatContext *	m_context { nullptr }
AVDictionary *	m_dict { nullptr }
	FFmpeg tag dictionary. More...
Protected Attributes inherited from ImageMetaData
QString	m_filePath
	Image filepath. More...

Additional Inherited Members
Public Types inherited from ImageMetaData
using	TagMap = QMultiMap< QString, QStringList >
Static Public Member Functions inherited from ImageMetaData
static ImageMetaData *	FromPicture (const QString &filePath)
	Factory to retrieve metadata from pictures. More...
static ImageMetaData *	FromVideo (const QString &filePath)
	Factory to retrieve metadata from videos. More...
static QString	ToString (const QString &name, const QString &label, const QString &value)
	Encodes metadata into a string as <tag name><tag label><tag value> More...
static QStringList	FromString (const QString &str)
	Decodes metadata name, label, value from a string. More...
static TagMap	ToMap (const QStringList &tags)
	Creates a map of metadata tags as. More...
Static Public Attributes inherited from ImageMetaData
static const QString	kSeparator = "|-|"
	Unique separator to delimit fields within a string. More...

Detailed Description

Reads video metadata tags using FFmpeg Raw values for Orientation & Date are read quickly via FFmpeg API.

However, as collating and interpreting other tags is messy and dependant on internal FFmpeg changes, informational data is derived via mythffprobe (a slow operation)

Definition at line 427 of file imagemetadata.cpp.

Constructor & Destructor Documentation

VideoMetaData()

VideoMetaData::VideoMetaData ( const QString &  filePath )

explicit

Constructor. Opens best video stream from video.

Parameters

filePath

Absolute video path

Definition at line 453 of file imagemetadata.cpp.

~VideoMetaData()

VideoMetaData::~VideoMetaData ( )

override

Destructor. Closes file.

Definition at line 476 of file imagemetadata.cpp.

Member Function Documentation

GetAllTags()

QStringList VideoMetaData::GetAllTags ( )

overridevirtual

Reads relevant video metadata by running mythffprobe.

Warning

Blocks for up to 5 secs

As video tags are unstructured they are massaged into groups of format, stream0, streamN to segregate them and permit reasonable display ordering. The stream indices reflect the stream order returned by mythffprobe and do not necessarily correlate with FFmpeg streams

Returns

List of encoded video metadata tags

See also

ImageMetaData::FromString()

Implements ImageMetaData.

Definition at line 493 of file imagemetadata.cpp.

GetComment()

QString VideoMetaData::GetComment ( bool *  exists = nullptr )

overridevirtual

Read Video comment from metadata.

Always empty

Parameters

[out]

exists

(Optional) Always false

Returns

Empty comment

Implements ImageMetaData.

Definition at line 630 of file imagemetadata.cpp.

GetOrientation()

int VideoMetaData::GetOrientation ( bool *  exists = nullptr )

overridevirtual

Read FFmpeg video orientation tag.

Parameters

[out]

exists

(Optional) True if orientation is defined by metadata

Returns

Exif orientation code

Implements ImageMetaData.

Definition at line 603 of file imagemetadata.cpp.

GetOriginalDateTime()

QDateTime VideoMetaData::GetOriginalDateTime ( bool *  exists = nullptr )

overridevirtual

Read video datestamp.

Parameters

[out]

exists

(Optional) True if datestamp is defined by metadata

Returns

Timestamp (possibly invalid) in camera timezone

Implements ImageMetaData.

Definition at line 615 of file imagemetadata.cpp.

GetTag()

QString VideoMetaData::GetTag ( const QString &  key, bool *  exists = nullptr  )

protected

Read a single video tag.

Parameters

[in]	key	FFmpeg tag name
[out]	exists	(Optional) True if tag exists in metadata

Returns

Tag value as a string

Definition at line 577 of file imagemetadata.cpp.

Referenced by GetOrientation(), and GetOriginalDateTime().

IsValid()

bool VideoMetaData::IsValid ( void  )

inlineoverridevirtual

Implements ImageMetaData.

Definition at line 433 of file imagemetadata.cpp.

Referenced by GetAllTags(), VideoMetaData(), and ~VideoMetaData().

Member Data Documentation

m_context

AVFormatContext* VideoMetaData::m_context { nullptr }

protected

Definition at line 443 of file imagemetadata.cpp.

Referenced by VideoMetaData(), and ~VideoMetaData().

m_dict

AVDictionary* VideoMetaData::m_dict { nullptr }

protected

FFmpeg tag dictionary.

Definition at line 445 of file imagemetadata.cpp.

Referenced by GetTag(), IsValid(), and VideoMetaData().

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

• mythtv/libs/libmythmetadata/imagemetadata.cpp