The QVideoFrame class provides a representation of a frame of video data. More...

Public Types
enum	FieldType

enum	PixelFormat

Public Methods
	QVideoFrame ()

	QVideoFrame (const QImage &image)

	QVideoFrame (const QVideoFrame &other)

	QVideoFrame (int bytes, const QSize &size, int bytesPerLine, PixelFormat format)

	QVideoFrame (QAbstractVideoBuffer *buffer, const QSize &size, PixelFormat format)

	~QVideoFrame ()

QVariantMap	availableMetaData () const

uchar *	bits ()

const uchar *	bits () const

uchar *	bits (int plane)

const uchar *	bits (int plane) const

int	bytesPerLine () const

int	bytesPerLine (int plane) const

qint64	endTime () const

FieldType	fieldType () const

QVariant	handle () const

QAbstractVideoBuffer::HandleType	handleType () const

int	height () const

bool	isMapped () const

bool	isReadable () const

bool	isValid () const

bool	isWritable () const

bool	map (QAbstractVideoBuffer::MapMode mode)

QAbstractVideoBuffer::MapMode	mapMode () const

int	mappedBytes () const

QVariant	metaData (const QString &key) const

bool	operator!= (const QVideoFrame &other) const

QVideoFrame &	operator= (const QVideoFrame &other)

bool	operator== (const QVideoFrame &other) const

PixelFormat	pixelFormat () const

int	planeCount () const

void	setEndTime (qint64 time)

void	setFieldType (FieldType field)

void	setMetaData (const QString &key, const QVariant &value)

void	setStartTime (qint64 time)

QSize	size () const

qint64	startTime () const

void	unmap ()

int	width () const

Static Public Methods
static QImage::Format	imageFormatFromPixelFormat (PixelFormat format)

static PixelFormat	pixelFormatFromImageFormat (QImage::Format format)

Detailed Description

The QVideoFrame class provides a representation of a frame of video data.

A QVideoFrame encapsulates the data of a video frame, and information about the frame.

The contents of a video frame can be mapped to memory using the map() function. While mapped the video data can accessed using the bits() function which returns a pointer to a buffer, the total size of which is given by the mappedBytes(), and the size of each line is given by bytesPerLine(). The return value of the handle() function may be used to access frame data using the internal buffer's native APIs.

The video data in a QVideoFrame is encapsulated in a QAbstractVideoBuffer. A QVideoFrame may be constructed from any buffer type by subclassing the QAbstractVideoBuffer class.

Note: QVideoFrame is explicitly shared, any change made to video frame will also apply to any copies.

See also: pixelFormatFromImageFormat()

Member Enumeration Documentation

enum QVideoFrame::FieldType

Specifies the field an interlaced video frame belongs to.

Constant	Value	Description
`QVideoFrame::ProgressiveFrame`	`0`	The frame is not interlaced.
`QVideoFrame::TopField`	`1`	The frame contains a top field.
`QVideoFrame::BottomField`	`2`	The frame contains a bottom field.
`QVideoFrame::InterlacedFrame`	`3`	The frame contains a merged top and bottom field.

enum QVideoFrame::PixelFormat

Enumerates video data types.

Constant	Value	Description
`QVideoFrame::Format_Invalid`	`0`	The frame is invalid.
`QVideoFrame::Format_ARGB32`	`1`	The frame is stored using a 32-bit ARGB format (0xAARRGGBB). Equivalent to QImage::Format_ARGB32.
`QVideoFrame::Format_ARGB32_Premultiplied`	`2`	The frame stored using a premultiplied 32-bit ARGB format (0xAARRGGBB). Equivalent to QImage::Format_ARGB32_Premultiplied.
`QVideoFrame::Format_RGB32`	`3`	The frame stored using a 32-bit RGB format (0xffRRGGBB). Equivalent to QImage::Format_RGB32
`QVideoFrame::Format_RGB24`	`4`	The frame is stored using a 24-bit RGB format (8-8-8). Equivalent to QImage::Format_RGB888
`QVideoFrame::Format_RGB565`	`5`	The frame is stored using a 16-bit RGB format (5-6-5). Equivalent to QImage::Format_RGB16.
`QVideoFrame::Format_RGB555`	`6`	The frame is stored using a 16-bit RGB format (5-5-5). Equivalent to QImage::Format_RGB555.
`QVideoFrame::Format_ARGB8565_Premultiplied`	`7`	The frame is stored using a 24-bit premultiplied ARGB format (8-6-6-5).
`QVideoFrame::Format_BGRA32`	`8`	The frame is stored using a 32-bit ARGB format (0xBBGGRRAA).
`QVideoFrame::Format_BGRA32_Premultiplied`	`9`	The frame is stored using a premultiplied 32bit BGRA format.
`QVideoFrame::Format_BGR32`	`10`	The frame is stored using a 32-bit BGR format (0xBBGGRRff).
`QVideoFrame::Format_BGR24`	`11`	The frame is stored using a 24-bit BGR format (0xBBGGRR).
`QVideoFrame::Format_BGR565`	`12`	The frame is stored using a 16-bit BGR format (5-6-5).
`QVideoFrame::Format_BGR555`	`13`	The frame is stored using a 16-bit BGR format (5-5-5).
`QVideoFrame::Format_BGRA5658_Premultiplied`	`14`	The frame is stored using a 24-bit premultiplied BGRA format (5-6-5-8).
`QVideoFrame::Format_AYUV444`	`15`	The frame is stored using a packed 32-bit AYUV format (0xAAYYUUVV).
`QVideoFrame::Format_AYUV444_Premultiplied`	`16`	The frame is stored using a packed premultiplied 32-bit AYUV format (0xAAYYUUVV).
`QVideoFrame::Format_YUV444`	`17`	The frame is stored using a 24-bit packed YUV format (8-8-8).
`QVideoFrame::Format_YUV420P`	`18`	The frame is stored using an 8-bit per component planar YUV format with the U and V planes horizontally and vertically sub-sampled, i.e. the height and width of the U and V planes are half that of the Y plane.
`QVideoFrame::Format_YV12`	`19`	The frame is stored using an 8-bit per component planar YVU format with the V and U planes horizontally and vertically sub-sampled, i.e. the height and width of the V and U planes are half that of the Y plane.
`QVideoFrame::Format_UYVY`	`20`	The frame is stored using an 8-bit per component packed YUV format with the U and V planes horizontally sub-sampled (U-Y-V-Y), i.e. two horizontally adjacent pixels are stored as a 32-bit macropixel which has a Y value for each pixel and common U and V values.
`QVideoFrame::Format_YUYV`	`21`	The frame is stored using an 8-bit per component packed YUV format with the U and V planes horizontally sub-sampled (Y-U-Y-V), i.e. two horizontally adjacent pixels are stored as a 32-bit macropixel which has a Y value for each pixel and common U and V values.
`QVideoFrame::Format_NV12`	`22`	The frame is stored using an 8-bit per component semi-planar YUV format with a Y plane (Y) followed by a horizontally and vertically sub-sampled, packed UV plane (U-V).
`QVideoFrame::Format_NV21`	`23`	The frame is stored using an 8-bit per component semi-planar YUV format with a Y plane (Y) followed by a horizontally and vertically sub-sampled, packed VU plane (V-U).
`QVideoFrame::Format_IMC1`	`24`	The frame is stored using an 8-bit per component planar YUV format with the U and V planes horizontally and vertically sub-sampled. This is similar to the Format_YUV420P type, except that the bytes per line of the U and V planes are padded out to the same stride as the Y plane.
`QVideoFrame::Format_IMC2`	`25`	The frame is stored using an 8-bit per component planar YUV format with the U and V planes horizontally and vertically sub-sampled. This is similar to the Format_YUV420P type, except that the lines of the U and V planes are interleaved, i.e. each line of U data is followed by a line of V data creating a single line of the same stride as the Y data.
`QVideoFrame::Format_IMC3`	`26`	The frame is stored using an 8-bit per component planar YVU format with the V and U planes horizontally and vertically sub-sampled. This is similar to the Format_YV12 type, except that the bytes per line of the V and U planes are padded out to the same stride as the Y plane.
`QVideoFrame::Format_IMC4`	`27`	The frame is stored using an 8-bit per component planar YVU format with the V and U planes horizontally and vertically sub-sampled. This is similar to the Format_YV12 type, except that the lines of the V and U planes are interleaved, i.e. each line of V data is followed by a line of U data creating a single line of the same stride as the Y data.
`QVideoFrame::Format_Y8`	`28`	The frame is stored using an 8-bit greyscale format.
`QVideoFrame::Format_Y16`	`29`	The frame is stored using a 16-bit linear greyscale format. Little endian.
`QVideoFrame::Format_User`	`1000`	Start value for user defined pixel formats.

Constructor & Destructor Documentation

QVideoFrame::QVideoFrame ( )

Constructs a null video frame.

QVideoFrame::QVideoFrame	(	QAbstractVideoBuffer *	buffer,
		const QSize &	size,
		PixelFormat	format
	)

Constructs a video frame from a buffer of the given pixel format and size in pixels.

Note: This does not increment the reference count of the video buffer.

QVideoFrame::QVideoFrame	(	int	bytes,
		const QSize &	size,
		int	bytesPerLine,
		PixelFormat	format
	)

Constructs a video frame of the given pixel format and size in pixels.

The bytesPerLine (stride) is the length of each scan line in bytes, and bytes is the total number of bytes that must be allocated for the frame.

QVideoFrame::QVideoFrame ( const QImage & image )

Constructs a video frame from an image.

Note: This will construct an invalid video frame if there is no frame type equivalent to the image format.

See also: pixelFormatFromImageFormat()

QVideoFrame::QVideoFrame ( const QVideoFrame & other )

Constructs a copy of other.

QVideoFrame::~QVideoFrame ( )

Destroys a video frame.

Method Documentation

QVariantMap QVideoFrame::availableMetaData ( ) const

Returns any extra metadata associated with this frame.

uchar * QVideoFrame::bits ( )

Returns a pointer to the start of the frame data buffer. This value is only valid while the frame data is mapped.

See also: map(), mappedBytes(), bytesPerLine()

const uchar * QVideoFrame::bits ( ) const

Returns a const pointer to the start of the frame data buffer. This value is only valid while the frame data is mapped.

See also: map(), mappedBytes(), bytesPerLine()

uchar * QVideoFrame::bits ( int plane )

Returns a pointer to the start of the frame data buffer for a plane. This value is only valid while the frame data is mapped.

If the buffer was not mapped with read access, the contents of this buffer will initially be uninitialized.

See also: map(), mappedBytes(), bytesPerLine(), planeCount()

const uchar * QVideoFrame::bits ( int plane ) const

Returns a const pointer to the start of the frame data buffer for a plane. This value is only valid while the frame data is mapped.

If the buffer was not mapped with read access, the contents of this buffer will initially be uninitialized.

See also: map(), mappedBytes(), bytesPerLine(), planeCount()

int QVideoFrame::bytesPerLine ( ) const

Returns the number of bytes in a scan line. This value is only valid while the frame data is mapped.

Note: This is the bytes per line of the first plane only. The bytes per line of subsequent planes should be calculated as per the frame type.

See also: bits(), map(), mappedBytes()

int QVideoFrame::bytesPerLine ( int plane ) const

Returns the number of bytes in a scan line of a plane. This value is only valid while the frame data is mapped.

See also: bits(), map(), mappedBytes(), planeCount()

qint64 QVideoFrame::endTime ( ) const

Returns the presentation time when a frame should stop being displayed.

See also: setEndTime()

FieldType QVideoFrame::fieldType ( ) const

Returns the field an interlaced video frame belongs to. If the video is not interlaced this will return WholeFrame.

See also: setFieldType()

QVariant QVideoFrame::handle ( ) const

Returns a type specific handle to a video frame's buffer. For an OpenGL texture this would be the texture ID.

See also: QAbstractVideoBuffer::handle()

QAbstractVideoBuffer::HandleType QVideoFrame::handleType ( ) const

Returns the type of a video frame's handle.

int QVideoFrame::height ( ) const

Returns the height of a video frame.

QImage::Format QVideoFrame::imageFormatFromPixelFormat ( PixelFormat format )

static

Returns an image format equivalent to a video frame pixel format. If there is no equivalent format QImage::Format_Invalid is returned instead.

bool QVideoFrame::isMapped ( ) const

Identifies if a video frame's contents are currently mapped to system memory. Returns true if the contents of the video frame are mapped to system memory and false otherwise. This method checks if the MapMode of the frame is not equal to QAbstractVideoBuffer::NotMapped.

See also: mapMode(), QAbstractVideoBuffer::MapMode

bool QVideoFrame::isReadable ( ) const

Identifies if the mapped contents of a video frame were read from the frame when it was mapped. This method checks if the MapMode contains the QAbstractVideoBuffer::WriteOnly flag. Returns true if the contents of the mapped memory were read from the video frame, and false otherwise.

See also: mapMode(), QAbstractVideoBuffer::MapMode

bool QVideoFrame::isValid ( ) const

Identifies whether a video frame is valid.

An invalid frame has no video buffer associated with it.

Returns true if the frame is valid, and false if it is not.

bool QVideoFrame::isWritable ( ) const

Identifies if the mapped contents of a video frame will be persisted when the frame is unmapped. This method checks if the MapMode contains the QAbstractVideoBuffer::WriteOnly flag. Returns true if the video frame will be updated when unmapped, and false otherwise.

Note: The result of altering the data of a frame that is mapped in read-only mode is undefined. Depending on the buffer implementation the changes may be persisted, or worse alter a shared buffer.

See also: mapMode(), QAbstractVideoBuffer::MapMode

bool QVideoFrame::map ( QAbstractVideoBuffer::MapMode mode )

Maps the contents of a video frame to memory. Returns true if the buffer was mapped to memory in the given mode and false otherwise.

The map mode indicates whether the contents of the mapped memory should be read from and/or written to the frame. If the map mode includes the QAbstractVideoBuffer::ReadOnly flag the mapped memory will be populated with the content of the video frame when mapped. If the map mode includes the QAbstractVideoBuffer::WriteOnly flag the content of the mapped memory will be persisted in the frame when unmapped.

While mapped the contents of a video frame can be accessed directly through the pointer returned by the bits() method. When access to the data is no longer needed be sure to call unmap() to release the mapped memory.

See also: unmap(), mapMode(), bits()

QAbstractVideoBuffer::MapMode QVideoFrame::mapMode ( ) const

Returns the mode a video frame was mapped to system memory in.

See also: map(), QAbstractVideoBuffer::MapMode

int QVideoFrame::mappedBytes ( ) const

Returns the number of bytes occupied by the mapped frame data.

This value is only valid while the frame data is mapped.

See also: map()

QVariant QVideoFrame::metaData ( const QString & key ) const

Returns any metadata for this frame for the given key. This might include frame specific information from a camera, or subtitles from a decoded video stream.

Refer to the documentation for the relevant video frame producer for further information about available metadata.

See also: setMetaData()

bool QVideoFrame::operator!= ( const QVideoFrame & other ) const

Returns true if this QVideoFrame and other do not reflect the same frame.

QVideoFrame & QVideoFrame::operator= ( const QVideoFrame & other )

Copy assigns from other and returns a reference to this object.

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

Returns true if this QVideoFrame and other reflect the same frame.

PixelFormat QVideoFrame::pixelFormat ( ) const

Returns the color format of a video frame.

PixelFormat QVideoFrame::pixelFormatFromImageFormat ( QImage::Format format )

static

Returns an video pixel format equivalent to an image format. If there is no equivalent format QVideoFrame::InvalidType is returned instead.

int QVideoFrame::planeCount ( ) const

Returns the number of planes in the video frame. This value is only valid while the frame data is mapped.

See also: map()

void QVideoFrame::setEndTime ( qint64 time )

Sets the presentation time when a frame should stop being displayed.

See also: endTime()

void QVideoFrame::setFieldType ( FieldType field )

Sets the field an interlaced video frame belongs to.

See also: fieldType()

void QVideoFrame::setMetaData	(	const QString &	key,
		const QVariant &	value
	)

Sets the metadata for the given key to value. If value is a null variant, any metadata for this key will be removed.

The producer of the video frame might use this to associate certain data with this frame, or for an intermediate processor to add information for a consumer of this frame.

See also: metaData()

void QVideoFrame::setStartTime ( qint64 time )

Sets the presentation time when the frame should be displayed.

See also: startTime()

QSize QVideoFrame::size ( ) const

Returns the size of a video frame.

qint64 QVideoFrame::startTime ( ) const

Returns the presentation time when the frame should be displayed.

See also: setStartTime()

void QVideoFrame::unmap ( )

Releases the memory mapped by the map() function.

If the MapMode included the QAbstractVideoBuffer::WriteOnly flag this will persist the current content of the mapped memory to the video frame.

See also: map()

int QVideoFrame::width ( ) const

Returns the width of a video frame.

Public Types

Public Methods

Static Public Methods

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Method Documentation