内容

• 公共类型
• 公共函数
• 静态公共成员
• 详细描述

QVideoFrame 类

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

头：	#include <QVideoFrame>
Since:	Qt 4.6

• 所有成员列表，包括继承成员

公共类型

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

公共函数

	QVideoFrame ()
	QVideoFrame (QAbstractVideoBuffer * buffer , const QSize & size , PixelFormat format )
	QVideoFrame (int bytes , const QSize & size , int bytesPerLine , PixelFormat format )
	QVideoFrame (const QImage & image )
	QVideoFrame (const QVideoFrame & other )
	~QVideoFrame ()
uchar *	bits ()
const uchar *	bits () const
int	bytesPerLine () 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
PixelFormat	pixelFormat () const
void	setEndTime (qint64 time )
void	setFieldType (FieldType field )
void	setStartTime (qint64 time )
QSize	size () const
qint64	startTime () const
void	unmap ()
int	width () const
QVideoFrame &	operator= (const QVideoFrame & other )

静态公共成员

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

详细描述

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 ()。返回值对于 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 。 QVideoFrame may be constructed from any buffer type by subclassing the QAbstractVideoBuffer 类。

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

成员类型文档编制

enum QVideoFrame:: FieldType

指定隔行扫描视频帧所属的字段。

常量	值	描述
QVideoFrame::ProgressiveFrame	0	帧非隔行扫描。
QVideoFrame::TopField	1	帧包含 top 字段。
QVideoFrame::BottomField	2	框架包含 bottom 字段。
QVideoFrame::InterlacedFrame	3	帧包含合并的 top 和 bottom 字段。

enum QVideoFrame:: PixelFormat

枚举视频数据类型。

常量	值	描述
QVideoFrame::Format_Invalid	0	帧无效。
QVideoFrame::Format_ARGB32	1	使用 32 位 ARGB 格式 (0xAARRGGBB) 存储帧。这相当于 QImage::Format_ARGB32 .
QVideoFrame::Format_ARGB32_Premultiplied	2	使用预乘 32 位 ARGB 格式 (0xAARRGGBB) 存储帧。这相当于 QImage::Format_ARGB32_Premultiplied .
QVideoFrame::Format_RGB32	3	使用 32 位 RGB 格式 (0xffRRGGBB) 存储帧。这相当于 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	帧使用 16 位 BGR 格式 (5-6-5) 存储。
QVideoFrame::Format_BGR555	13	帧使用 16 位 BGR 格式 (5-5-5) 存储。
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	使用 8 位灰度格式存储帧。
QVideoFrame::Format_Y16	29	使用 16 位线性灰度格式存储帧。小端在前。
QVideoFrame::Format_User	1000	用户定义像素格式的起始值。

成员函数文档编制

QVideoFrame:: QVideoFrame ()

构造 null 视频帧。

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

构造视频帧从 buffer of the given pixel format and size (以像素为单位)。

注意： 这不会递增视频缓冲的引用计数。

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

构造视频帧采用给定像素 format and size (以像素为单位)。

The bytesPerLine (步幅) 是每扫描行的长度 (以字节为单位)，和 bytes 是必须为帧分配的总字节数。

QVideoFrame:: QVideoFrame (const QImage & image )

构造视频帧从 image .

注意： 这会构造无效视频帧，若不存在等价图像格式的帧类型。

另请参阅 pixelFormatFromImageFormat ().

QVideoFrame:: QVideoFrame (const QVideoFrame & other )

构造副本为 other .

QVideoFrame:: ~QVideoFrame ()

销毁视频帧。

uchar * QVideoFrame:: bits ()

返回指向帧数据缓冲起始的指针。

此值才有效当帧数据为 mapped .

另请参阅 map (), mappedBytes ()，和 bytesPerLine ().

const uchar * QVideoFrame:: bits () const

返回指向帧数据缓冲起始的指针。

此值才有效当帧数据为 mapped .

另请参阅 map (), mappedBytes ()，和 bytesPerLine ().

int QVideoFrame:: bytesPerLine () const

返回扫描行字节数。

注意： 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.

此值才有效当帧数据为 mapped .

另请参阅 bits (), map ()，和 mappedBytes ().

qint64 QVideoFrame:: endTime () const

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

另请参阅 setEndTime ().

FieldType QVideoFrame:: fieldType () const

返回隔行扫描视频帧所属的字段。

若不是隔行扫描视频，这会返回 WholeFrame。

另请参阅 setFieldType ().

QVariant QVideoFrame:: handle () const

返回视频帧缓冲的特定类型句柄。

For an OpenGL texture this would be the texture ID.

另请参阅 QAbstractVideoBuffer::handle ().

QAbstractVideoBuffer::HandleType QVideoFrame:: handleType () const

返回视频帧的句柄类型。

int QVideoFrame:: height () const

返回视频帧的高度。

[static] QImage::Format QVideoFrame:: imageFormatFromPixelFormat ( PixelFormat format )

返回图像格式等效视频帧像素 format 。若没有等效格式 QImage::Format_Invalid 被返回取而代之。

bool QVideoFrame:: isMapped () const

标识目前是否把视频帧内容，映射到系统内存。

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.

另请参阅 mapMode () 和 QAbstractVideoBuffer::MapMode .

bool QVideoFrame:: isReadable () const

标识视频帧映射内容，是否是从帧读取当映射时。

这是方便校验函数若 MapMode 包含 QAbstractVideoBuffer::WriteOnly 标志。

返回 true 若从视频帧读取映射内存内容，和 false 否则。

另请参阅 mapMode () 和 QAbstractVideoBuffer::MapMode .

bool QVideoFrame:: isValid () const

标识视频帧是否有效。

无效帧没有关联它的视频缓冲。

返回 true 若帧有效，和 false 若帧无效。

bool QVideoFrame:: isWritable () const

标识视频帧的映射内容是否会持久化，当取消帧映射时。

这是方便校验函数若 MapMode 包含 QAbstractVideoBuffer::WriteOnly 标志。

返回 true 若将更新视频帧当取消映射时，否则返回 false。

注意： 更改以只读方式映射帧数据的结果未定义。从属缓冲实现，改变可能持久化，或更糟更改共享缓冲。

另请参阅 mapMode () 和 QAbstractVideoBuffer::MapMode .

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

Maps the contents of a video frame to memory.

映射 mode 指示映射内存内容是否应读取自和/或写入帧。若映射模式包括 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.

当映射时，可以直接访问视频帧内容透过指针返回通过 bits () 函数。

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 和 false 否则。

另请参阅 unmap (), mapMode ()，和 bits ().

QAbstractVideoBuffer::MapMode QVideoFrame:: mapMode () const

返回将视频帧映射到系统内存中的模式。

另请参阅 map () 和 QAbstractVideoBuffer::MapMode .

int QVideoFrame:: mappedBytes () const

返回由映射帧数据所占据的字节数。

此值才有效当帧数据为 mapped .

另请参阅 map ().

PixelFormat QVideoFrame:: pixelFormat () const

返回视频帧的颜色格式。

[static] PixelFormat QVideoFrame:: pixelFormatFromImageFormat ( QImage::Format format )

Returns an video pixel format equivalent to an image format 。若不存在等价格式，返回 QVideoFrame::InvalidType 代替。

void QVideoFrame:: setEndTime ( qint64 time )

设置呈现 time when a frame should stop being displayed.

另请参阅 endTime ().

void QVideoFrame:: setFieldType ( FieldType field )

设置 field 属于隔行扫描视频帧。

另请参阅 fieldType ().

void QVideoFrame:: setStartTime ( qint64 time )

设置呈现 time when the frame should be displayed.

另请参阅 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.

另请参阅 setStartTime ().

void QVideoFrame:: unmap ()

释放内存映射通过 map () 函数。

若 MapMode 包括 QAbstractVideoBuffer::WriteOnly 标志，则这会把映射内存当前内容坚持到视频帧。

另请参阅 map ().

int QVideoFrame:: width () const

返回视频帧的宽度。

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

赋值内容对于 other to a video frame.