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index.md
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---
title: "HTMLMediaElement: srcObject property"
short-title: srcObject
slug: Web/API/HTMLMediaElement/srcObject
page-type: web-api-instance-property
browser-compat: api.HTMLMediaElement.srcObject
---
{{APIRef("HTML DOM")}}
The **`srcObject`** property of the
{{domxref("HTMLMediaElement")}} interface sets or returns the object which serves as
the source of the media associated with the {{domxref("HTMLMediaElement")}}.
The object can be a {{domxref("MediaStream")}}, a {{domxref("MediaSource")}}, a
{{domxref("Blob")}}, or a {{domxref("File")}} (which inherits from `Blob`).
> **Note:** As of March 2020, only Safari has full support for `srcObject`, i.e. using `MediaSource`, `MediaStream`, `Blob`, and `File` objects as values. Other browsers support `MediaStream` objects; until they catch up, consider falling back to creating a URL with {{domxref("URL.createObjectURL_static", "URL.createObjectURL()")}} and assigning it to {{domxref("HTMLMediaElement.src")}} (see below for an example). In addition, as of version 108 Chromium supports attaching a dedicated worker `MediaSource` object by assigning that object's {{domxref("MediaSourceHandle")}} instance (transferred from the worker) to `srcObject`.
## Value
A {{domxref('MediaStream')}}, {{domxref('MediaSource')}}, {{domxref('Blob')}}, or
{{domxref('File')}} object (though see the compatibility table for what is actually
supported).
## Usage notes
Older versions of the Media Source specification required using
{{domxref("URL.createObjectURL_static", "URL.createObjectURL()")}} to create an object URL then
setting {{domxref("HTMLMediaElement.src", "src")}} to that URL. Now you can just set
`srcObject` to the {{domxref("MediaStream")}} directly.
## Examples
### Basic example
In this example, a {{domxref("MediaStream")}} from a camera is assigned to a
newly-created {{HTMLElement("video")}} element.
```js
const mediaStream = await navigator.mediaDevices.getUserMedia({ video: true });
const video = document.createElement("video");
video.srcObject = mediaStream;
```
In this example, a new {{domxref('MediaSource')}} is assigned to a newly-created
{{HTMLElement("video")}} element.
```js
const mediaSource = new MediaSource();
const video = document.createElement("video");
video.srcObject = mediaSource;
```
### Supporting fallback to the src property
The examples below support older browser versions that require you to create an object
URL and assign it to `src` if `srcObject` isn't supported.
First, a {{domxref("MediaStream")}} from a camera is assigned to a newly-created
{{HTMLElement("video")}} element, with fallback for older browsers.
```js
const mediaStream = await navigator.mediaDevices.getUserMedia({ video: true });
const video = document.createElement("video");
if ("srcObject" in video) {
video.srcObject = mediaStream;
} else {
// Avoid using this in new browsers, as it is going away.
video.src = URL.createObjectURL(mediaStream);
}
```
Second, a new {{domxref('MediaSource')}} is assigned to a newly-created
{{HTMLElement("video")}} element, with fallback for older browsers and browsers that
don't yet support assignment of {{domxref('MediaSource')}} directly.
```js
const mediaSource = new MediaSource();
const video = document.createElement("video");
// Older browsers may not have srcObject
if ("srcObject" in video) {
try {
video.srcObject = mediaSource;
} catch (err) {
if (err.name !== "TypeError") {
throw err;
}
// Even if they do, they may only support MediaStream
video.src = URL.createObjectURL(mediaSource);
}
} else {
video.src = URL.createObjectURL(mediaSource);
}
```
### Constructing a `MediaSource` in a worker and passing it to the main thread to play
The {{domxref("MediaSource.handle")}} property can be accessed inside a dedicated worker and the resulting {{domxref("MediaSourceHandle")}} object is then transferred over to the thread that created the worker (in this case the main thread) via a {{domxref("DedicatedWorkerGlobalScope.postMessage()", "postMessage()")}} call:
```js
// Inside dedicated worker
let mediaSource = new MediaSource();
let handle = mediaSource.handle;
// Transfer the handle to the context that created the worker
postMessage({ arg: handle }, [handle]);
mediaSource.addEventListener("sourceopen", () => {
// Await sourceopen on MediaSource before creating SourceBuffers
// and populating them with fetched media — MediaSource won't
// accept creation of SourceBuffers until it is attached to the
// HTMLMediaElement and its readyState is "open"
});
```
Over in the main thread, we receive the handle via a {{domxref("Worker.message_event", "message")}} event handler, attach it to a {{htmlelement("video")}} via its {{domxref("HTMLMediaElement.srcObject")}} property, and {{domxref("HTMLMediaElement.play()", "play")}} the video:
```js
worker.addEventListener("message", (msg) => {
let mediaSourceHandle = msg.data.arg;
video.srcObject = mediaSourceHandle;
video.play();
});
```
> **Note:** {{domxref("MediaSourceHandle")}}s cannot be successfully transferred into or via a shared worker or service worker.
## Specifications
{{Specifications}}
## Browser compatibility
{{Compat}}