Media Capture and Streams API (Media Stream)

媒體捕獲和流API,通常被稱為媒體流 API或者乾脆MediaStream API,是關係到一個 API的 WebRTC提供流式音頻和視頻數據的支持。它提供了用於處理流及其組成軌道的接口和方法,與數據格式關聯的約束,異步使用數據時的成功和錯誤回調以及在此過程中觸發的事件。

概念和用法

該 API 基於MediaStream對象的操作,該對象代表與音頻或視頻相關的數據流。請參閱「獲取視頻」中的示例。

A MediaStream consists of zero or more MediaStreamTrack objects, representing various audio or video tracks. Each MediaStreamTrack may have one or more channels. The channel represents the smallest unit of a media stream, such as an audio signal associated with a given speaker, like left or right in a stereo audio track.

MediaStream objects have a single input and a single output. A MediaStream object generated by getUserMedia() is called local, and has as its source input one of the user's cameras or microphones. A non-local MediaStream may be representing to a media element, like <video> or <audio>, a stream originating over the network, and obtained via the WebRTC RTCPeerConnection API, or a stream created using the Web Audio API MediaStreamAudioSourceNode.

The output of the MediaStream object is linked to a consumer. It can be a media elements, like <audio> or <video>, the WebRTC RTCPeerConnection API or a Web Audio API MediaStreamAudioSourceNode.

Interfaces

In these reference articles, you'll find the fundamental information you'll need to know about each of the interfaces that make up the Media Capture and Streams API.

Early versions of the Media Capture and Streams API specification included separate AudioStreamTrack and VideoStreamTrack interfaces—each based upon MediaStreamTrack—which represented streams of those types. These no longer exist, and you should update any existing code to instead use MediaStreamTrack directly.

Events

Guides and tutorials

The articles below provide additional guidance and how-to information that will help you learn to use the API, and how to perform specific tasks that you may wish to handle.

Browser compatibility

api.MediaStream

BCD tables only load in the browser

api.MediaStreamTrack

BCD tables only load in the browser

api.MediaDevices

BCD tables only load in the browser

api.MediaDeviceInfo

BCD tables only load in the browser

api.InputDeviceInfo

BCD tables only load in the browser

api.CanvasCaptureMediaStreamTrack

BCD tables only load in the browser

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