QVideoFrame

QVideoFrame 

#include <QVideoFrame>

 

 

Public Types

enum	FieldType { ProgressiveFrame, TopField, BottomField, InterlacedFrame }
enum	PixelFormat { Format_Invalid, Format_ARGB32, Format_ARGB32_Premultiplied, Format_RGB32, ..., Format_User }

Public Functions

	QVideoFrame()
	QVideoFrame(QAbstractVideoBuffer *buffer, const QSize &size, QVideoFrame::PixelFormat format)
	QVideoFrame(int bytes, const QSize &size, int bytesPerLine, QVideoFrame::PixelFormat format)
	QVideoFrame(const QImage &image)
	QVideoFrame(const QVideoFrame &other)
	~QVideoFrame()
QVariantMap	availableMetaData() const
uchar *	bits()
uchar *	bits(int plane)
const uchar *	bits() const
const uchar *	bits(int plane) const
int	bytesPerLine() const
int	bytesPerLine(int plane) const
qint64	endTime() const
QVideoFrame::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
QVideoFrame::PixelFormat	pixelFormat() const
int	planeCount() const
void	setEndTime(qint64 time)
void	setFieldType(QVideoFrame::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
bool	operator!=(const QVideoFrame &other) const
QVideoFrame &	operator=(const QVideoFrame &other)
bool	operator==(const QVideoFrame &other) const

Static Public Members

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

 

 

 

详细说明

QVideoFrame类表示一帧视频数据。

 

QVideoFrame封装视频帧的像素数据以及关于该帧的信息。

 

视频帧可以来自多个地方——解码媒体、相机或程序生成。在这些帧中描述像素的方式可能会有很大的变化，一些像素格式以牺牲易用性为代价提供了更大的压缩机会。

 

视频帧的像素内容可以使用map（）函数映射到内存。映射时，可以使用bits（）函数访问视频数据，该函数返回一个指向缓冲区的指针。这个缓冲区的总大小由mappedBytes（）函数给定，每行的大小由bytesPerLine（）函数给出。handle（）函数的返回值也可以用于使用内部缓冲区的本地API（例如OpenGL纹理句柄）访问帧数据。

 

视频帧也可以具有与其相关联的时间戳信息。QAbstractVideoSurface的实现可以使用这些时间戳来确定何时开始和停止显示帧，但并非所有曲面都会遵守此设置。

 

QVideoFrame中的视频像素数据被封装在QAbstractVideoBuffer中。通过对QAbstractVideoBuffer类进行子类化，可以从任何缓冲区类型构造QVideoFrame。

 

注意：由于视频帧的复制成本可能很高，QVideoFrame是明确共享的，因此对视频帧所做的任何更改也将适用于任何副本。

 

指定隔行扫描视频帧所属的字段。

 

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). 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 (8-5-6-5).
QVideoFrame::Format_BGRA32	8	The frame is stored using a 32-bit BGRA 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_Jpeg	30	The frame is stored in compressed Jpeg format.
QVideoFrame::Format_CameraRaw	31	The frame is stored using a device specific camera raw format.
QVideoFrame::Format_AdobeDng	32	The frame is stored using raw Adobe Digital Negative (DNG) format.
QVideoFrame::Format_User	1000	Start value for user defined pixel formats.

 

 

 

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