HTMLMediaElement
The HTMLMediaElement
interface adds to HTMLElement
the properties and methods needed to support basic media-related capabilities that are common to audio and video. The HTMLVideoElement
(en-US) and HTMLAudioElement
(en-US) elements both inherit this interface.
屬性
這個介面從HTMLElement
、Element
、Node
,和EventTarget
繼承了屬性
HTMLMediaElement.audioTracks
(en-US)-
AudioTrackList
(en-US) 會列出包含在該媒體元素內部的AudioTrack
(en-US)物件。 HTMLMediaElement.autoplay
(en-US)-
是一個布林值,表達了 HTML 中是否有
autoplay
(en-US)屬性;意即;表明是否只要在媒體可以播放且不中斷的時候,能夠自動播放。備註: 在網站上自動播放音訊(或是有音訊的影片),可能是惱人的使用者體驗;因此,應該盡可能地避免。如果你必須要有自動播放的功能,你應該讓它是可選擇的(讓使用者特地去啟動)。 However, this can be useful when creating media elements whose source will be set at a later time, under user control.
HTMLMediaElement.buffered
(en-US) Read only-
回傳一個
TimeRanges
(en-US)物件,表示媒體當下buffered
屬性被瀏覽器存取時的緩存(如果有的話)區間。 HTMLMediaElement.controller
(en-US)-
Is a
MediaController
object that represents the media controller assigned to the element, ornull
if none is assigned. HTMLMediaElement.controls
(en-US)-
Is a
Boolean
that reflects thecontrols
(en-US) HTML attribute, indicating whether user interface items for controlling the resource should be displayed. HTMLMediaElement.controlsList
(en-US) Read only-
Returns a
DOMTokenList
that helps the user agent select what controls to show on the media element whenever the user agent shows its own set of controls. TheDOMTokenList
takes one or more of three possible values:nodownload
,nofullscreen
, andnoremoteplayback
. HTMLMediaElement.crossOrigin
(en-US)-
Is a
DOMString
indicating the CORS setting (en-US) for this media element. HTMLMediaElement.currentSrc
(en-US) Read only-
Returns a
DOMString
with the absolute URL of the chosen media resource. HTMLMediaElement.currentTime
(en-US)-
Is a
double
indicating the current playback time in seconds. Setting this value seeks the media to the new time. HTMLMediaElement.defaultMuted
(en-US)-
Is a
Boolean
that reflects themuted
(en-US) HTML attribute, which indicates whether the media element's audio output should be muted by default. HTMLMediaElement.defaultPlaybackRate
(en-US)-
Is a
double
indicating the default playback rate for the media. HTMLMediaElement.disableRemotePlayback
(en-US)-
Is a
Boolean
that sets or returns the remote playback state, indicating whether the media element is allowed to have a remote playback UI. HTMLMediaElement.duration
(en-US) Read only-
Returns a
double
indicating the length of the media in seconds, or 0 if no media data is available. HTMLMediaElement.ended
(en-US) Read only-
Returns a
Boolean
that indicates whether the media element has finished playing. HTMLMediaElement.error
(en-US) Read only-
Returns a
MediaError
(en-US) object for the most recent error, ornull
if there has not been an error. HTMLMediaElement.loop
(en-US)-
Is a
Boolean
that reflects theloop
(en-US) HTML attribute, which indicates whether the media element should start over when it reaches the end. HTMLMediaElement.mediaGroup
(en-US)-
Is a
DOMString
that reflects themediagroup
(en-US) HTML attribute, which indicates the name of the group of elements it belongs to. A group of media elements shares a commonMediaController
. HTMLMediaElement.mediaKeys
(en-US) Read only 實驗性質-
Returns a
MediaKeys
(en-US) object ornull
. MediaKeys is a set of keys that an associated HTMLMediaElement can use for decryption of media data during playback. HTMLMediaElement.mozAudioCaptured
Read only 非標準-
Returns a
Boolean
. Related to audio stream capture. HTMLMediaElement.mozFragmentEnd
非標準-
Is a
double
that provides access to the fragment end time if the media element has a fragment URI forcurrentSrc
, otherwise it is equal to the media duration. HTMLMediaElement.mozFrameBufferLength
非標準 已棄用-
Is a
unsigned long
that indicates the number of samples that will be returned in the framebuffer of eachMozAudioAvailable
event. This number is a total for all channels, and by default is set to be the number of channels * 1024 (e.g., 2 channels * 1024 samples = 2048 total).ThemozFrameBufferLength
property can be set to a new value for lower latency, larger amounts of data, etc. The size given must be a number between 512 and 16384. Using any other size results in an exception being thrown. The best time to set a new length is after the loadedmetadata (en-US) event fires, when the audio info is known, but before the audio has started orMozAudioAvailable
events have begun firing. HTMLMediaElement.mozSampleRate
Read only 非標準 已棄用-
Returns a
double
representing the number of samples per second that will be played. For example, 44100 samples per second is the sample rate used by CD audio. HTMLMediaElement.muted
(en-US)-
Is a
Boolean
that determines whether audio is muted.true
if the audio is muted andfalse
otherwise. HTMLMediaElement.networkState
(en-US) Read only-
Returns a
unsigned short
(enumeration) indicating the current state of fetching the media over the network. HTMLMediaElement.paused
(en-US) Read only-
Returns a
Boolean
that indicates whether the media element is paused. HTMLMediaElement.playbackRate
(en-US)-
Is a
double
that indicates the rate at which the media is being played back. HTMLMediaElement.played
Read only-
Returns a
TimeRanges
(en-US) object that contains the ranges of the media source that the browser has played, if any. HTMLMediaElement.preload
-
Is a
DOMString
that reflects thepreload
(en-US) HTML attribute, indicating what data should be preloaded, if any. Possible values are:none
,metadata
,auto
. HTMLMediaElement.preservesPitch
(en-US) 非標準-
Is a
Boolean
that determines if the pitch of the sound will be preserved. If set tofalse
, the pitch will adjust to the speed of the audio. This is implemented with prefixes in Firefox (mozPreservesPitch
) and WebKit (webkitPreservesPitch
). HTMLMediaElement.readyState
Read only-
Returns a
unsigned short
(enumeration) indicating the readiness state of the media. HTMLMediaElement.seekable
(en-US) Read only-
Returns a
TimeRanges
(en-US) object that contains the time ranges that the user is able to seek to, if any. HTMLMediaElement.seeking
Read only-
Returns a
Boolean
that indicates whether the media is in the process of seeking to a new position. HTMLMediaElement.sinkId
(en-US) Read only 實驗性質-
Returns a
DOMString
that is the unique ID of the audio device delivering output, or an empty string if it is using the user agent default. This ID should be one of theMediaDeviceInfo.deviceid
values returned fromMediaDevices.enumerateDevices()
,id-multimedia
, orid-communications
. HTMLMediaElement.src
(en-US)-
Is a
DOMString
that reflects thesrc
(en-US) HTML attribute, which contains the URL of a media resource to use. HTMLMediaElement.srcObject
(en-US)-
Is a
MediaStream
(en-US) representing the media to play or that has played in the currentHTMLMediaElement
, ornull
if not assigned. HTMLMediaElement.textTracks
(en-US) Read only-
Returns the list of
TextTrack
(en-US) objects contained in the element. HTMLMediaElement.videoTracks
(en-US) Read only-
Returns the list of
VideoTrack
(en-US) objects contained in the element.備註: Gecko supports only single track playback, and the parsing of tracks' metadata is only available for media with the Ogg container format.
HTMLMediaElement.volume
(en-US)-
Is a
double
indicating the audio volume, from 0.0 (silent) to 1.0 (loudest).
Event handlers
HTMLMediaElement.onencrypted
(en-US)-
Sets the
EventHandler
(en-US) called when the media is encrypted. HTMLMediaElement.onwaitingforkey
(en-US)-
Sets the
EventHandler
(en-US) called when playback is blocked while waiting for an encryption key.
Obsolete attributes
These attributes are obsolete and should not be used, even if a browser still supports them.
HTMLMediaElement.initialTime
Read only 非標準 已棄用-
Returns a
double
that indicates the initial playback position in seconds. HTMLMediaElement.mozChannels
Read only 非標準 已棄用-
Returns a
double
representing the number of channels in the audio resource (e.g.,2
for stereo).
Obsolete event handlers
HTMLMediaElement.onmozinterruptbegin
非標準 已棄用-
Sets the event handler called when the media element is interrupted because of the Audio Channel manager. This was Firefox-specific, having been implemented for Firefox OS, and was removed in Firefox 55.
HTMLMediaElement.onmozinterruptend
非標準 已棄用-
Sets the
EventHandler
(en-US) called when the interruption is concluded. This was Firefox-specific, having been implemented for Firefox OS, and was removed in Firefox 55.
Methods
This interface also inherits methods from its ancestors HTMLElement
, Element
, Node
, and EventTarget
.
HTMLMediaElement.addTextTrack()
-
Adds a text track (such as a track for subtitles) to a media element.
HTMLMediaElement.captureStream()
(en-US) 實驗性質-
Returns
MediaStream
(en-US), captures a stream of the media content. HTMLMediaElement.canPlayType()
(en-US)-
Determines whether the specified media type can be played back.
HTMLMediaElement.fastSeek()
(en-US)-
Directly seeks to the given time.
HTMLMediaElement.load()
(en-US)-
Resets the media element and restarts the media resource. Any pending events are discarded. How much media data is fetched is still affected by the
preload
attribute. This method can be useful for releasing resources after anysrc
attribute andsource
element descendants have been removed. Otherwise, it is usually unnecessary to use this method, unless required to rescansource
element children after dynamic changes. HTMLMediaElement.mozCaptureStream()
非標準-
[enter description]
HTMLMediaElement.mozCaptureStreamUntilEnded()
非標準-
[enter description]
HTMLMediaElement.mozGetMetadata()
非標準-
Returns
Object
, which contains properties that represent metadata from the playing media resource as{key: value}
pairs. A separate copy of the data is returned each time the method is called. This method must be called after the loadedmetadata (en-US) event fires. HTMLMediaElement.pause()
(en-US)-
Pauses the media playback.
HTMLMediaElement.play()
(en-US)-
Begins playback of the media.
HTMLMediaElement.seekToNextFrame()
(en-US) 非標準 實驗性質-
Seeks to the next frame in the media. This non-standard, experimental method makes it possible to manually drive reading and rendering of media at a custom speed, or to move through the media frame-by-frame to perform filtering or other operations.
HTMLMediaElement.setMediaKeys()
(en-US) 實驗性質-
Returns
Promise
. Sets theMediaKeys
(en-US) keys to use when decrypting media during playback. HTMLMediaElement.setSinkId()
(en-US) 實驗性質-
Sets the ID of the audio device to use for output and returns a
Promise
. This only works when the application is authorized to use the specified device.
Obsolete methods
These methods are obsolete and should not be used, even if a browser still supports them.
HTMLMediaElement.mozLoadFrom()
非標準 已棄用-
This method, available only in Mozilla's implementation, loads data from another media element. This works similarly to
load()
except that instead of running the normal resource selection algorithm, the source is simply set to theother
element'scurrentSrc
. This is optimized so this element gets access to all of theother
element's cached and buffered data; in fact, the two elements share downloaded data, so data downloaded by either element is available to both.
Specifications
Specification |
---|
HTML Standard # htmlmediaelement |
Browser compatibility
BCD tables only load in the browser
See also
- References
<video>
(en-US) and<audio>
(en-US) HTML elements.HTMLVideoElement
(en-US) andHTMLAudioElement
(en-US) interfaces, derived fromHTMLMediaElement
.
- Articles