内容

• 特性
• 信号
• 方法
• 详细描述

Video QML 类型

用于展示指定视频的方便类型。 更多...

import 语句：	import QtMultimedia
继承：	Item

• 所有成员列表，包括继承成员

特性

• bufferProgress : real
• duration : int
• error : enumeration
• errorString : string
• fillMode : enumeration
• hasAudio : bool
• hasVideo : bool
• metaData : mediaMetaData
• muted : bool
• orientation : int
• playbackRate : real
• playbackState : enumeration
• position : int
• seekable : bool
• source : url
• volume : real

信号

• paused ()
• playing ()
• stopped ()

方法

• pause ()
• play ()
• seek ( offset )
• stop ()

详细描述

视频 is a convenience type combining the functionality of a MediaPlayer 和 VideoOutput into one. It provides simple video playback functionality without having to declare multiple types.

The following is sample code to implement video playback in a scene.

Video {
    id: video
    width : 800
    height : 600
    source: "video.avi"
    MouseArea {
        anchors.fill: parent
        onClicked: {
            video.play()
        }
    }
    focus: true
    Keys.onSpacePressed: video.playbackState == MediaPlayer.PlayingState ? video.pause() : video.play()
    Keys.onLeftPressed: video.seek(video.position - 5000)
    Keys.onRightPressed: video.seek(video.position + 5000)
}
					

The source file, video.avi , plays when you click the parent of MouseArea . The video plays in an area of 800 by 600 pixels, and its id property has the value video .

Notice that because signals for the Keys have been defined pressing the:

• Spacebar toggles the pause button.
• Left Arrow moves the current position in the video to 5 seconds previously.
• Right Arrow advances the current position in the video by 5 seconds.

Video supports un-transformed, stretched, and uniformly scaled video presentation. For a description of stretched uniformly scaled presentation, see the fillMode property description.

另请参阅 MediaPlayer and VideoOutput .

特性文档编制

bufferProgress : real

This property holds how much of the data buffer is currently filled, from 0.0 (empty) to 1.0 (full).

duration : int

This property holds the duration of the media in milliseconds.

If the media doesn't have a fixed duration (a live stream for example) this will be 0.

error : enumeration

This property holds the error state of the video. It can be one of:

• MediaPlayer . NoError - there is no current error.
• MediaPlayer .ResourceError - the video cannot be played due to a problem allocating resources.
• MediaPlayer .FormatError - the video format is not supported.
• MediaPlayer .NetworkError - the video cannot be played due to network issues.
• MediaPlayer .AccessDenied - the video cannot be played due to insufficient permissions.
• MediaPlayer .ServiceMissing - the video cannot be played because the media service could not be instantiated.

errorString : string

This property holds a string describing the current error condition in more detail.

fillMode : enumeration

Set this property to define how the video is scaled to fit the target area.

• VideoOutput .Stretch - the video is scaled to fit
• VideoOutput .PreserveAspectFit - the video is scaled uniformly to fit without cropping
• VideoOutput .PreserveAspectCrop - the video is scaled uniformly to fill, cropping if necessary

Because this type is for convenience in QML, it does not support enumerations directly, so enumerations from VideoOutput are used to access the available fill modes.

The default fill mode is preserveAspectFit.

hasAudio : bool

This property holds whether the current media has audio content.

hasVideo : bool

This property holds whether the current media has video content.

metaData : mediaMetaData

This property holds the meta data for the current media.

见 MediaPlayer.metaData for details about each meta data key.

另请参阅 mediaMetaData .

muted : bool

This property holds whether the audio output is muted.

orientation : int

The orientation of the 视频 in degrees. Only multiples of 90 degrees is supported, that is 0, 90, 180, 270, 360, etc.

playbackRate : real

This property holds the rate at which video is played at as a multiple of the normal rate.

playbackState : enumeration

This read only property indicates the playback state of the media.

• MediaPlayer .PlayingState - the media is playing
• MediaPlayer .PausedState - the media is paused
• MediaPlayer .StoppedState - the media is stopped

The default state is MediaPlayer .StoppedState.

position : int

This property holds the current playback position in milliseconds.

To change this position, use the seek() 方法。

另请参阅 seek() .

seekable : bool

This property holds whether the playback position of the video can be changed.

If true, calling the seek() method will cause playback to seek to the new position.

source : url

This property holds the source URL of the media.

volume : real

This property holds the audio volume.

The volume is scaled linearly from 0.0 (无声) 到 1.0 (full volume). Values outside this range will be clamped.

默认音量为 1.0 .

UI volume controls should usually be scaled nonlinearly. For example, using a logarithmic scale will produce linear changes in perceived loudness, which is what a user would normally expect from a volume control. See QAudio::convertVolume() 了解更多细节。

信号文档编制

paused ()

This signal is emitted when playback is paused.

注意： 相应处理程序是 onPaused .

playing ()

This signal is emitted when playback is started or continued.

注意： 相应处理程序是 onPlaying .

stopped ()

This signal is emitted when playback is stopped.

注意： 相应处理程序是 onStopped .

方法文档编制

pause ()

Pauses playback of the media.

play ()

Starts playback of the media.

seek ( offset )

若 seekable property is true, seeks the current playback position to offset .

Seeking may be asynchronous, so the position property may not be updated immediately.

另请参阅 seekable and position .

stop ()

Stops playback of the media.