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  2. Qt 5.9.9
  3. Qt Multimedia
  4. QML 类型
  5. 音频 QML 类型

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音频 QML 类型

把音频回放添加到场景。 更多...

import 语句： import QtMultimedia 5.8

特性

信号

方法

详细描述 

Text {
    text: "Click Me!";
    font.pointSize: 24;
    width: 150; height: 50;
    Audio {
        id: playMusic
        source: "music.wav"
    }
    MouseArea {
        id: playArea
        anchors.fill: parent
        onPressed:  { playMusic.play() }
    }
}

另请参阅 Video .

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.

可以检索支持的值，采用 supportedAudioRoles() .

值可以是之一：

  • UnknownRole - the role is unknown or undefined.
  • MusicRole - 音乐。
  • VideoRole - soundtrack from a movie or a video.
  • VoiceCommunicationRole - voice communications, such as telephony.
  • AlarmRole - 闹钟。
  • NotificationRole - notification, such as an incoming e-mail or a chat request.
  • RingtoneRole - 铃声。
  • AccessibilityRole - for accessibility, such as with a screen reader.
  • SonificationRole - sonification, such as with user interface sounds.
  • GameRole- 游戏音频。

该 QML 特性在 Qt 5.6 引入。

autoLoad : bool

This property indicates if loading of media should begin immediately.

默认为 true 。若 false , the media will not be loaded until playback is started.

autoPlay : bool

This property controls whether the media will begin to play on start up.

默认为 false 。若设为 true ，值 autoLoad 将覆写成 true .

availability : enumeration

Returns the availability state of the media player.

This is one of:

值 描述
Available The media player is available to use.
Busy The media player is usually available, but some other process is utilizing the hardware necessary to play media.
Unavailable There are no supported media playback facilities.
ResourceMissing There is one or more resources missing, so the media 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 (空) 到 1.0 (完整)。

Playback can start or resume only when the buffer is entirely filled, in which case the status is Audio.Buffered or Audio.Buffering 。值低于 1.0 隐含状态 Audio.Stalled .

另请参阅 status .

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 audio. It can be one of:

值 描述
NoError 当前没有错误。
ResourceError The audio cannot be played due to a problem allocating resources.
FormatError 音频格式不支持。
NetworkError The audio cannot be played due to network issues.
AccessDenied The audio cannot be played due to insufficient permissions.
ServiceMissing The audio 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.

hasAudio : bool

此特性保持媒体是否包含音频。

hasVideo : bool

此特性保持媒体是否包含视频。

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 Audio.Infinite 以启用无限循环。

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 .

mediaObject : variant

此特性保持本机媒体对象。

It can be used to get a pointer to a QMediaPlayer object in order to integrate with C++ code. 

QObject *qmlAudio; // The QML Audio object
QMediaPlayer *player = qvariant_cast<QMediaPlayer *>(qmlAudio->property("mediaObject"));

注意： This property is not accessible from QML.

metaData 组

metaData.title : variant

metaData.subTitle : variant

metaData.author : variant

metaData.comment : variant

metaData.description : variant

metaData.category : variant

metaData.genre : variant

metaData.year : variant

metaData.date : variant

metaData.userRating : variant

metaData.keywords : variant

metaData.language : variant

metaData.publisher : variant

metaData.copyright : variant

metaData.parentalRating : variant

metaData.ratingOrganization : variant

metaData.size : variant

metaData.mediaType : variant

metaData.audioBitRate : variant

metaData.audioCodec : variant

metaData.averageLevel : variant

metaData.channelCount : variant

metaData.peakValue : variant

metaData.sampleRate : variant

metaData.albumTitle : variant

metaData.albumArtist : variant

metaData.contributingArtist : variant

metaData.composer : variant

metaData.conductor : variant

metaData.lyrics : variant

metaData.mood : variant

metaData.trackNumber : variant

metaData.trackCount : variant

metaData.coverArtUrlSmall : variant

metaData.coverArtUrlLarge : variant

metaData.resolution : variant

metaData.pixelAspectRatio : variant

metaData.videoFrameRate : variant

metaData.videoBitRate : variant

metaData.videoCodec : variant

metaData.posterUrl : variant

metaData.chapterNumber : variant

metaData.director : variant

metaData.leadPerformer : variant

metaData.writer : variant

这些特性保持用于当前媒体的元数据。

  • metaData.title - 媒体标题。
  • metaData.subTitle - 媒体子标题。
  • metaData.author - 媒体作者。
  • metaData.comment - 关于媒体的用户评论。
  • metaData.description - 媒体描述。
  • metaData.category - 媒体类别。
  • metaData.genre - 媒体流派。
  • metaData.year - 媒体发行年份。
  • metaData.date - 媒体日期。
  • metaData.userRating - a user rating of the media in the range of 0 to 100.
  • metaData.keywords - a list of keywords describing the media.
  • metaData.language - the language of the media, as an ISO 639-2 code.
  • metaData.publisher - 媒体出版商。
  • metaData.copyright - the media's copyright notice.
  • metaData.parentalRating - the parental rating of the media.
  • metaData.ratingOrganization - the name of the rating organization responsible for the parental rating of the media.
  • metaData.size - 媒体的大小 (以字节为单位)。
  • metaData.mediaType - 媒体类型。
  • metaData.audioBitRate - the bit rate of the media's audio stream in bits per second.
  • metaData.audioCodec - the encoding of the media audio stream.
  • metaData.averageLevel - the average volume level of the media.
  • metaData.channelCount - the number of channels in the media's audio stream.
  • metaData.peakValue - the peak volume of media's audio stream.
  • metaData.sampleRate - the sample rate of the media's audio stream in hertz.
  • metaData.albumTitle - the title of the album the media belongs to.
  • metaData.albumArtist - the name of the principal artist of the album the media belongs to.
  • metaData.contributingArtist - the names of artists contributing to the media.
  • metaData.composer - the composer of the media.
  • metaData.conductor - the conductor of the media.
  • metaData.lyrics - 媒体歌词。
  • metaData.mood - the mood of the media.
  • metaData.trackNumber - the track number of the media.
  • metaData.trackCount - the number of tracks on the album containing the media.
  • metaData.coverArtUrlSmall - the URL of a small cover art image.
  • metaData.coverArtUrlLarge - the URL of a large cover art image.
  • metaData.resolution - the dimension of an image or video.
  • metaData.pixelAspectRatio - the pixel aspect ratio of an image or video.
  • metaData.videoFrameRate - the frame rate of the media's video stream.
  • metaData.videoBitRate - the bit rate of the media's video stream in bits per second.
  • metaData.videoCodec - the encoding of the media's video stream.
  • metaData.posterUrl - the URL of a poster image.
  • metaData.chapterNumber - the chapter number of the media.
  • metaData.director - the director of the media.
  • metaData.leadPerformer - the lead performer in the media.
  • metaData.writer - 媒体作家。

另请参阅 QMediaMetaData .

muted : bool

此特性保持音频输出是否静音。

默认为 false。

notifyInterval : int

The interval at which notifiable properties will update.

须申报特性是 position and bufferProgress .

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

This QML property was introduced in Qt 5.9.

playbackRate : real

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

默认为 1.0。

playbackState : enumeration

This property holds the state of media playback. It can be one of:

  • PlayingState - 媒体目前正播放。
  • PausedState - 媒体回放已挂起。
  • StoppedState - 媒体回放尚未开始。

playlist : Playlist

此特性保持用于媒体播放器的播放列表。

设置播放列表特性重置 source 成空字符串。

该 QML 特性在 Qt 5.6 引入。

position : int

此特性保持当前的回放位置 (以毫秒为单位)。

要改变此位置，使用 seek() 方法。

另请参阅 seek() .

seekable : bool

This property holds whether position of the audio can be changed.

若 true，调用 seek() method will cause playback to seek to the new position.

source : url

此特性保持媒体的源 URL (统一资源定位符)。

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:

  • NoMedia - 尚未设置媒体。
  • Loading - the media is currently being loaded.
  • Loaded - the media has been loaded.
  • Buffering - the media is buffering data.
  • Stalled - playback has been interrupted while the media is buffering data.
  • Buffered - the media has buffered data.
  • EndOfMedia - the media has played to the end.
  • InvalidMedia - the media cannot be played.
  • UnknownStatus - the status of the media is unknown.

volume : real

此特性保持音频音量。

按线性比例缩放的音量是从 0.0 (无声) 到 1.0 (全音量)。将钳制超出此范围的值。

默认音量为 1.0 .

通常，UI 音量控件应按非线性比例缩放。例如，使用对数比例缩放将产生感知响度的线性变化，这通常是用户期望的音量控制。见 QtMultimedia.convertVolume() 了解更多细节。


信号文档编制

error ( error , errorString )

此信号发射，当 error 出现。 errorString parameter may contain more detailed information about the error.

相应处理程序是 onError .

paused ()

此信号发射，当暂停回放时。

相应处理程序是 onPaused .

playbackStateChanged ()

此信号被发射当 playbackState 特性变更。

相应处理程序是 onPlaybackStateChanged .

playing ()

This signal is emitted when playback is started or resumed.

相应处理程序是 onPlaying .

stopped ()

此信号发射，当停止回放时。

相应处理程序是 onStopped .


方法文档编制

pause ()

暂停媒体回放。

设置 playbackState property to PausedState.

play ()

开始媒体回放。

设置 playbackState property to PlayingState.

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 ()

停止媒体回放。

设置 playbackState 特性成 StoppedState。

list < int > supportedAudioRoles ()

返回支持的音频角色列表。

若不支持设置的音频角色，返回空列表。

This QML method was introduced in Qt 5.6.

另请参阅 audioRole .