Media Capabilities API

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 determining 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 say MediaRecorder.isTypeSupported() or HTMLMediaElement.canPlayType(), which only address general browser support, not performance. The API also provides abilities to access display property information such as supported color gamut, dynamic range abilities, and real-time feedback about the playback.

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.

Media capabilities information enables websites to enable adaptive streaming to alter the quality of content based on actual user-perceived quality, and react to a pick of CPU/GPU usage in real time.

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.

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.

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}`);
    });
}

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