QVideoFrame Class Reference

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

  1. #include <QVideoFrame>

This class was introduced in Qt 4.6.

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.

Public Types

Toggle detailsenum QVideoFrame::

FieldTypeFieldType { ProgressiveFrame , TopField , BottomField , InterlacedFrame 3 ...} { ProgressiveFrame , TopField , BottomField , InterlacedFrame 3 }

Specifies the field an interlaced video frame belongs to.

ConstantValueDescription
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.

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Toggle detailsenum QVideoFrame::

PixelFormatPixelFormat { Format_Invalid , Format_ARGB32 , Format_ARGB32_Premultiplied , Format_RGB32 , Format_RGB24 , Format_RGB565 , Format_RGB555 , Format_ARGB8565_Premultiplied , Format_BGRA32 , Format_BGRA32_Premultiplied , Format_BGR32 , Format_BGR24 , Format_BGR565 , Format_BGR555 , Format_BGRA5658_Premultiplied , Format_AYUV444 , Format_AYUV444_Premultiplied , Format_YUV444 , Format_YUV420P , Format_YV12 , Format_UYVY , Format_YUYV , Format_NV12 , Format_NV21 , Format_IMC1 , Format_IMC2 , Format_IMC3 , Format_IMC4 , Format_Y8 , Format_Y16 , Format_User 1000 ...} { Format_Invalid , Format_ARGB32 , Format_ARGB32_Premultiplied , Format_RGB32 , Format_RGB24 , Format_RGB565 , Format_RGB555 , Format_ARGB8565_Premultiplied , Format_BGRA32 , Format_BGRA32_Premultiplied , Format_BGR32 , Format_BGR24 , Format_BGR565 , Format_BGR555 , Format_BGRA5658_Premultiplied , Format_AYUV444 , Format_AYUV444_Premultiplied , Format_YUV444 , Format_YUV420P , Format_YV12 , Format_UYVY , Format_YUYV , Format_NV12 , Format_NV21 , Format_IMC1 , Format_IMC2 , Format_IMC3 , Format_IMC4 , Format_Y8 , Format_Y16 , Format_User 1000 }

Enumerates video data types.

ConstantValueDescription
QVideoFrame::Format_Invalid 0 The frame is invalid.
QVideoFrame::Format_ARGB32 1 The frame is stored using a 32-bit ARGB format (0xAARRGGBB). This is equivalent to QImage::Format_ARGB32.
QVideoFrame::Format_ARGB32_Premultiplied 2 The frame stored using a premultiplied 32-bit ARGB format (0xAARRGGBB). This is equivalent to QImage::Format_ARGB32_Premultiplied.
QVideoFrame::Format_RGB32 3 The frame stored using a 32-bit RGB format (0xffRRGGBB). This is equivalent to QImage::Format_RGB32
QVideoFrame::Format_RGB24 4 The frame is stored using a 24-bit RGB format (8-8-8). This is equivalent to QImage::Format_RGB888
QVideoFrame::Format_RGB565 5 The frame is stored using a 16-bit RGB format (5-6-5). This is equivalent to QImage::Format_RGB16.
QVideoFrame::Format_RGB555 6 The frame is stored using a 16-bit RGB format (5-5-5). This is 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.

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    Public Functions

    Toggle details QVideoFrame

    QVideoFrameQVideoFrame () ()

    Constructs a null video frame.

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    Toggle details QVideoFrame

    QVideoFrameQVideoFrame ( QAbstractVideoBuffer *buffer , const QSize &size , PixelFormat format ...) ( 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 doesn't increment the reference count of the video buffer.

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    Toggle details QVideoFrame

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

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    Toggle details QVideoFrame

    QVideoFrameQVideoFrame ( const QImage &image ) ( 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().

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    Toggle details QVideoFrame

    QVideoFrameQVideoFrame ( const QVideoFrame &other ) ( const QVideoFrame &other )

    Constructs a copy of other.

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    Toggle details QVideoFrame

    ~QVideoFrame~QVideoFrame () ()

    Destroys a video frame.

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    Toggle details uchar * QVideoFrame

    bitsbits () ()

    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(), and bytesPerLine().

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    Toggle details const uchar * QVideoFrame

    bitsbits () ()const

    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(), and bytesPerLine().

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    Toggle details int QVideoFrame

    bytesPerLinebytesPerLine () ()const

    Returns the number of bytes in a scan line.

    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.

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

    See also bits(), map(), and mappedBytes().

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    Toggle details qint64 QVideoFrame

    endTimeendTime () ()const

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

    See also setEndTime().

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    Toggle details FieldType QVideoFrame

    fieldTypefieldType () ()const

    Returns the field an interlaced video frame belongs to.

    If the video is not interlaced this will return WholeFrame.

    See also setFieldType().

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    Toggle details QVariant QVideoFrame

    handlehandle () ()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().

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    Toggle details QAbstractVideoBuffer::HandleType QVideoFrame

    handleTypehandleType () ()const

    Returns the type of a video frame's handle.

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    Toggle details int QVideoFrame

    heightheight () ()const

    Returns the height of a video frame.

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    Toggle details QImage::Format QVideoFrame

    imageFormatFromPixelFormatimageFormatFromPixelFormat ( PixelFormat format ...) ( 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.

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    Toggle details bool QVideoFrame

    isMappedisMapped () ()const

    Identifies if a video frame's contents are currently mapped to system memory.

    This is a convenience function which checks that the MapMode of the frame is not equal to QAbstractVideoBuffer::NotMapped.

    Returns true if the contents of the video frame are mapped to system memory, and false otherwise.

    See also mapMode() and QAbstractVideoBuffer::MapMode.

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    Toggle details bool QVideoFrame

    isReadableisReadable () ()const

    Identifies if the mapped contents of a video frame were read from the frame when it was mapped.

    This is a convenience function which 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() and QAbstractVideoBuffer::MapMode.

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    Toggle details bool QVideoFrame

    isValidisValid () ()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.

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    Toggle details bool QVideoFrame

    isWritableisWritable () ()const

    Identifies if the mapped contents of a video frame will be persisted when the frame is unmapped.

    This is a convenience function which 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() and QAbstractVideoBuffer::MapMode.

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    Toggle details bool QVideoFrame

    mapmap ( QAbstractVideoBuffer::MapMode mode ) ( QAbstractVideoBuffer::MapMode mode )

    Maps the contents of a video frame to memory.

    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 inclues 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() function.

    When access to the data is no longer needed be sure to call the unmap() function to release the mapped memory.

    Returns true if the buffer was mapped to memory in the given mode and false otherwise.

    See also unmap(), mapMode(), and bits().

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    Toggle details QAbstractVideoBuffer::MapMode QVideoFrame

    mapModemapMode () ()const

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

    See also map() and QAbstractVideoBuffer::MapMode.

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    Toggle details int QVideoFrame

    mappedBytesmappedBytes () ()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().

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    Toggle details PixelFormat QVideoFrame

    pixelFormatpixelFormat () ()const

    Returns the color format of a video frame.

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    Toggle details PixelFormat QVideoFrame

    pixelFormatFromImageFormatpixelFormatFromImageFormat ( QImage::Format format ...) ( 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.

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    Toggle details void QVideoFrame

    setEndTimesetEndTime ( qint64 time ) ( qint64 time )

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

    See also endTime().

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    Toggle details void QVideoFrame

    setFieldTypesetFieldType ( FieldType field ) ( FieldType field )

    Sets the field an interlaced video frame belongs to.

    See also fieldType().

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    Toggle details void QVideoFrame

    setStartTimesetStartTime ( qint64 time ) ( qint64 time )

    Sets the presentation time when the frame should be displayed.

    See also startTime().

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    Toggle details QSize QVideoFrame

    sizesize () ()const

    Returns the size of a video frame.

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    Toggle details qint64 QVideoFrame

    startTimestartTime () ()const

    Returns the presentation time when the frame should be displayed.

    See also setStartTime().

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    Toggle details void QVideoFrame

    unmapunmap () ()

    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().

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    Toggle details int QVideoFrame

    widthwidth () ()const

    Returns the width of a video frame.

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    Toggle details QVideoFrame & QVideoFrame

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

    Assigns the contents of other to a video frame.

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