内容

• 特性
• 信号
• 方法
• 详细描述

Audio QML Type

Add audio playback to a scene. 更多...

import 语句：

import QtMultimedia 5.8

• 所有成员列表，包括继承成员

特性

• audioRole : enumeration
• autoLoad : bool
• autoPlay : bool
• availability : enumeration
• bufferProgress : real
• duration : int
• error : enumeration
• errorString : string
• hasAudio : bool
• hasVideo : bool
• loops : int
• mediaObject : variant
• metaData
  • 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
• muted : bool
• notifyInterval : int
• playbackRate : real
• playbackState : enumeration
• playlist : Playlist
• position : int
• seekable : bool
• source : url
• status : enumeration
• volume : real

信号

• error ( error , errorString )
• paused ()
• playbackStateChanged ()
• playing ()
• stopped ()

方法

• pause ()
• play ()
• seek ( offset )
• stop ()
• list<int> supportedAudioRoles ()

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 视频 .

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:

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

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 , the value of autoLoad will be overwritten to 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 . A value lower than 1.0 implies that the status is 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	There is no current error.
ResourceError	The audio cannot be played due to a problem allocating resources.
FormatError	The audio format is not supported.
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

This property holds whether the media contains audio.

hasVideo : bool

This property holds whether the media contains video.

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 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 .

mediaObject : variant

This property holds the native media object.

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 group
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

These properties hold the meta data for the current media.

• metaData.title - the title of the media.
• metaData.subTitle - the sub-title of the media.
• metaData.author - the author of the media.
• metaData.comment - a user comment about the media.
• metaData.description - a description of the media.
• metaData.category - the category of the media.
• metaData.genre - the genre of the media.
• metaData.year - the year of release of the media.
• metaData.date - the date of the media.
• 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 - the publisher of the media.
• 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 - the size of the media in bytes.
• metaData.mediaType - the type of the media.
• 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 - the lyrics to the media.
• 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 - the writer of the media.

另请参阅 QMediaMetaData .

muted : bool

This property holds whether the audio output is muted.

Defaults to false.

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.

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.

Defaults to 1.0.

playbackState : enumeration

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

• PlayingState - the media is currently playing.
• PausedState - playback of the media has been suspended.
• StoppedState - playback of the media is yet to begin.

playlist : Playlist

This property holds the playlist used by the media player.

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

该 QML 特性在 Qt 5.6 引入。

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 position of the audio 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:

• NoMedia - no media has been set.
• 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

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

error ( error , errorString )

此信号被发射当 error has occurred. The errorString parameter may contain more detailed information about the error.

相应处理程序是 onError .

paused ()

This signal is emitted when playback is paused.

相应处理程序是 onPaused .

playbackStateChanged ()

此信号被发射当 playbackState property is altered.

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 ()

This signal is emitted when playback is stopped.

相应处理程序是 onStopped .

方法文档编制

pause ()

Pauses playback of the media.

设置 playbackState property to PausedState.

play ()

Starts playback of the media.

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 ()

Stops playback of the media.

设置 playbackState property to StoppedState.

list < int > 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 QML method was introduced in Qt 5.6.

另请参阅 audioRole .