Video QML 类型

用于展示指定视频的方便类型。更多...

import 语句：	import QtMultimedia 5.15
继承：	Item

所有成员列表，包括继承成员

特性

audioRole : enumeration
autoLoad : bool
autoPlay : bool
availability : enumeration
bufferProgress : real
customAudioRole : string
duration : int
error : enumeration
errorString : string
fillMode : enumeration
flushMode : enumeration
hasAudio : bool
hasVideo : bool
loops : int
metaData : object
muted : bool
notifyInterval : int
orientation : int
playbackRate : real
playbackState : enumeration
playlist : Playlist
position : int
seekable : bool
source : url
status : enumeration
volume : real

信号

paused ()
playing ()
stopped ()

方法

pause ()
play ()
seek ( offset )
stop ()
supportedAudioRoles ()

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.

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)
}

视频 supports untransformed, 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

audioRole : enumeration

This property holds the role of the audio stream. It can be set to specify the type of audio being played, allowing the system to make appropriate decisions when it comes to volume, routing or post-processing.

The audio role must be set before setting the source property.

Supported values can be retrieved with supportedAudioRoles() .

The value can be one of:

MediaPlayer .UnknownRole - the role is unknown or undefined.
MediaPlayer .MusicRole - music.
MediaPlayer .VideoRole - soundtrack from a movie or a video.
MediaPlayer .VoiceCommunicationRole - voice communications, such as telephony.
MediaPlayer .AlarmRole - alarm.
MediaPlayer .NotificationRole - notification, such as an incoming e-mail or a chat request.
MediaPlayer .RingtoneRole - ringtone.
MediaPlayer .AccessibilityRole - for accessibility, such as with a screen reader.
MediaPlayer .SonificationRole - sonification, such as with user interface sounds.
MediaPlayer .GameRole - game audio.
MediaPlayer .CustomRole - The role is specified by customAudioRole .

customAudioRole is cleared when this property is set to anything other than CustomRole.

该特性在 Qt 5.6 引入。

autoLoad : bool

This property indicates if loading of media should begin immediately.

Defaults to true, if false media will not be loaded until playback is started.

autoPlay : bool

This property determines whether the media should begin playback automatically.

Setting to true also sets autoLoad to true 。默认为 false .

availability : enumeration

Returns the availability state of the video instance.

This is one of:

值	描述
MediaPlayer .Available	The video player is available to use.
MediaPlayer .Busy	The video player is usually available, but some other process is utilizing the hardware necessary to play media.
MediaPlayer .Unavailable	There are no supported video playback facilities.
MediaPlayer .ResourceMissing	There is one or more resources missing, so the video player cannot be used. It may be possible to try again at a later time.

bufferProgress : real

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

customAudioRole : string

This property holds the role of the audio stream when the backend supports audio roles unknown to Qt. It can be set to specify the type of audio being played, allowing the system to make appropriate decisions when it comes to volume, routing or post-processing.

The audio role must be set before setting the source property.

audioRole is set to CustomRole when this property is set.

该特性在 Qt 5.11 引入。

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.

flushMode : enumeration

Set this property to define what 视频 should show when playback is finished or stopped.

VideoOutput .EmptyFrame - clears video output.
VideoOutput .FirstFrame - shows the first valid frame.
VideoOutput .LastFrame - shows the last valid frame.

The default flush mode is EmptyFrame.

该特性在 Qt 5.15 引入。

hasAudio : bool

This property holds whether the current media has audio content.

hasVideo : bool

This property holds whether the current media has video content.

loops : int

This property holds the number of times the media is played. A value of 0 or 1 means the media will be played only once; set to MediaPlayer.Infinite to enable infinite looping.

The value can be changed while the media is playing, in which case it will update the remaining loops to the new value.

默认为 1 .

该特性在 Qt 5.9 引入。

metaData : 对象

This property holds the meta data for the current media.

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

另请参阅 QMediaMetaData .

muted : bool

This property holds whether the audio output is muted.

notifyInterval : int

The interval at which notifiable properties will update.

The notifiable properties are position and bufferProgress .

The interval is expressed in milliseconds, the default value is 1000.

该特性在 Qt 5.9 引入。

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.

playlist : Playlist

This property holds the playlist used by the media player.

Setting the playlist property resets the source to an empty string.

该特性在 Qt 5.6 引入。

位置 : 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.

Setting the source property clears the current playlist ，若有的话。

status : enumeration

This property holds the status of media loading. It can be one of:

MediaPlayer .NoMedia - no media has been set.
MediaPlayer .Loading - the media is currently being loaded.
MediaPlayer .Loaded - the media has been loaded.
MediaPlayer .Buffering - the media is buffering data.
MediaPlayer .Stalled - playback has been interrupted while the media is buffering data.
MediaPlayer .Buffered - the media has buffered data.
MediaPlayer .EndOfMedia - the media has played to the end.
MediaPlayer .InvalidMedia - the media cannot be played.
MediaPlayer .UnknownStatus - the status of the media cannot be determined.

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 QtMultimedia.convertVolume() 了解更多细节。

信号文档编制

paused ()

This signal is emitted when playback is paused.

相应处理程序是 onPaused .

注意： 相应处理程序是 onPaused .

playing ()

This signal is emitted when playback is started or continued.

相应处理程序是 onPlaying .

注意： 相应处理程序是 onPlaying .

stopped ()

This signal is emitted when playback is stopped.

相应处理程序是 onStopped .

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.

supportedAudioRoles ()

返回支持的音频角色列表。

If setting the audio role is not supported, an empty list is returned.

This method was introduced in Qt 5.6.

另请参阅 audioRole .