The MediaStream Recording API, sometimes simply referred to as the Media Recording API or the MediaRecorder API, is closely affiliated with the Media Capture and Streams API and the WebRTC API. The MediaStream Recording API makes it possible to capture the data generated by a MediaStream or HTMLMediaElement object for analysis, processing, or saving to disk. It's also surprisingly easy to work with.
The MediaStream Recording API is comprised of a single interface, MediaRecorder, which does all the work of taking the data from a MediaStream and delivering it to you for processing. The data is delivered by a series of dataavailable events, already in the format you specify when creating the MediaRecorder. The process of recording a stream is simple:
MediaStream or HTMLMediaElement (in the form of an <audio> or <video> element) to serve as the source of the media data.MediaRecorder.ondataavailable to an event handler for the dataavailable event; this will be called whenever data is available for you.MediaRecorder object, specifying the source stream and any desired options (such as the container's MIME type or the desired bit rates of its tracks.MediaRecorder.start() to begin recording.dataavailable event handler gets called every time there's data ready for you to do with as you will; the event has a data attribute whose value is a Blob that contains the media data. You can force a dataavailable event to occur, thereby delivering the latest sound to you so you can filter it, save it, or whatever.MediaRecorder.stop().Individual Blobs containing slices of the recorded media will not necessarily be individually playable. The media needs to be reassembled before playback.
If anything goes wrong during recording, an error event is sent to the MediaRecorder. You can listen for error events by setting up a onerror event handler.
You can also use the properties of the MediaRecorder object to determine the state of the recording process, and its pause() and resume() methods to pause and resume recording of the source media.
If you need or want to check to see if a specific MIME type is supported, that's possible as well. Just call MediaRecorder.isTypeSupported().
To learn more about using the MediaStream Recording API, see Using the MediaStream Recording API, which shows how to use the API to record audio clips. A second article, Recording a media element, describes how to receive a stream from an <audio> or <video> element and use the captured stream (in this case, recording it and saving it to a local disk).
BlobEventBlob form using a BlobEvent of type dataavailable.MediaRecorderMediaRecorderErrorEventerror property is a DOMException that specifies that error occurred.| Specification | Status | Comment |
|---|---|---|
| MediaStream Recording | Working Draft | Initial definition |
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Microsoft Edge | Opera | Safari (WebKit) |
|---|---|---|---|---|---|---|
| Basic support | 47.0 | 25.0 (25.0) | No support | ? | No support | No support |
| Feature | Android | Android Webview | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android |
|---|---|---|---|---|---|---|---|---|
| Basic support | No support | 47.0 | 25.0 (25.0) | 1.3[1] | No support | No support | No support | 47.0 |
[1] The initial Firefox OS implementation only supported audio recording.
[2] To use MediaRecorder in Chrome 47 and 48, enable experimental Web Platform features from the chrome://flags page.
[3] Audio recording works in Chrome 49 and above; Chrome 47 and 48 only support video recording.
navigator.mediaDevices.getUserMedia()
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https://developer.mozilla.org/en-US/docs/Web/API/MediaStream_Recording_API