Concepts

There are a myriad of video and audio codecs. Different browsers support different media types and new media types are always being developed. With the Media Capabilities API, developers can ensure each user is getting the best bitrate and storage savings for their browser, device, and OS capabilities.

Whether a device uses hardware or software decoding impacts how smooth and power efficient the video decoding is and how efficient the playback will be. The Media Capabilities API enables developers to determine which codecs are supported and how performant a media file will be both in terms of smoothness and power efficiency.

The Media Capabilities API provide more powerful features than other APIs such as MediaRecorder.isTypeSupported() or HTMLMediaElement.canPlayType(), which only address general browser support, not performance.

To test support, smoothness, and power efficiency for encoding and decoding video or audio content, you use the MediaCapabilities interface's encodingInfo() and decodingInfo() methods.

Interfaces

MediaCapabilities

Provides information about the decoding abilities of the device, system and browser based on codecs, profile, resolution, and bitrates. The information can be used to serve optimal media streams to the user and determine if playback should be smooth and power efficient.

Extensions to other interfaces

Navigator.mediaCapabilities Read only

A MediaCapabilities object that can expose information about the decoding and encoding capabilities for a given media format and output capabilities.

WorkerNavigator.mediaCapabilities Read only

A MediaCapabilities object that can expose information about the decoding and encoding capabilities for a given media format and output capabilities.

Examples

Detect audio file support and expected performance

This example defines an audio configuration then checks to see if the user agent supports decoding that media configuration, and whether it will perform well in terms of smoothness and power efficiency.

if ("mediaCapabilities" in navigator) {
  const audioFileConfiguration = {
    type: "file",
    audio: {
      contentType: "audio/mp3",
      channels: 2,
      bitrate: 132700,
      samplerate: 5200,
    },
  };

  navigator.mediaCapabilities
    .decodingInfo(audioFileConfiguration)
    .then((result) => {
      console.log(
        `This configuration is ${result.supported ? "" : "not "}supported,`,
      );
      console.log(`${result.smooth ? "" : "not "}smooth, and`);
      console.log(`${result.powerEfficient ? "" : "not "}power efficient.`);
    })
    .catch(() => {
      console.log(`decodingInfo error: ${contentType}`);
    });
}

Specifications

Browser compatibility

See also

• HTMLMediaElement's method canPlayType()
• MediaSource's method isTypeSupported()
• Using the Media Capabilities API