MediaCapabilitiesInfo - Web APIs 编辑

The MediaCapabilitiesInfo interface of the Media Capabilities API is made available when the promise returned by the MediaCapabilities.encodingInfo() or MediaCapabilities.decodingInfo() methods of the MediaCapabilities interface fulfills, providing information as to whether the media type is supported, and whether encoding or decoding such media would be smooth and power efficient.

Properties

The MediaCapabilitiesInfo interface contains three Boolean attribues:

• supported: Given the properties defined in the MediaConfiguration, can the specified piece of media content be encoded (if MediaEncodingConfiguration is set) or decode (if MediaDecodingConfiguration is set) at all? If yes, supported is true. Otherwise, it is false.
• smooth: Given the properties defined in the MediaConfiguration, will the playback of the specified piece of media be high quality? Will it be smooth?  If supported is true, and playback will be smooth, smooth is true, Otherwise, is it false.
• powerEfficient: Given the properties defined in the MediaConfiguration, will the playback of the specified piece of media be power efficient? If supported is true, and playback will be power efficient, powerEfficient is true, Otherwise, is it false.

Browsers will report a supported media configuration as smooth and powerEfficient until stats on this device have been recorded. All supported audio codecs are reported to be power efficient.

Example

// MediaConfiguration to be tested
const mediaConfig = {
    type : 'file',
    audio : {
        contentType : "audio/ogg",
        channels : 2,
        bitrate : 132700,
        samplerate : 5200
     },
};

// check support and performance
navigator.mediaCapabilities.decodingInfo(mediaConfig).then(result => { // result contains the media capabilities information
    console.log('This configuration is ' +
        (result.supported ? '' : 'not ') + 'supported, ' +             // Can the media, as configured, be decoded by the user agent
        (result.smooth ? '' : 'not ') + 'smooth, and ' +               // is it smooth?
        (result.powerEfficient ? '' : 'not ') + 'power efficient.')    // is it power efficient?
});

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• MediaConfiguration
• MediaCapabilities.encodingInfo()
• MediaCapabilities.decodingInfo()