recordrtc/dev/isMediaRecorderCompatible.js

RecordRTC is a server-less (entire client-side) JavaScript library can be used to record WebRTC audio/video media streams. It supports cross-browser audio/video recording.

function isMediaRecorderCompatible() {
    var isOpera = !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0;
    var isChrome = !!window.chrome && !isOpera;
    var isFirefox = typeof window.InstallTrigger !== 'undefined';

    if (isFirefox) {
        return true;
    }

    var nVer = navigator.appVersion;
    var nAgt = navigator.userAgent;
    var fullVersion = '' + parseFloat(navigator.appVersion);
    var majorVersion = parseInt(navigator.appVersion, 10);
    var nameOffset, verOffset, ix;

    if (isChrome || isOpera) {
        verOffset = nAgt.indexOf('Chrome');
        fullVersion = nAgt.substring(verOffset + 7);
    }

    // trim the fullVersion string at semicolon/space if present
    if ((ix = fullVersion.indexOf(';')) !== -1) {
        fullVersion = fullVersion.substring(0, ix);
    }

    if ((ix = fullVersion.indexOf(' ')) !== -1) {
        fullVersion = fullVersion.substring(0, ix);
    }

    majorVersion = parseInt('' + fullVersion, 10);

    if (isNaN(majorVersion)) {
        fullVersion = '' + parseFloat(navigator.appVersion);
        majorVersion = parseInt(navigator.appVersion, 10);
    }

    return majorVersion >= 49;
}