Edit in JSFiddle

(function localFileVideoPlayerInit(win) {
    var URL = win.URL || win.webkitURL,
        displayMessage = (function displayMessageInit() {
            var node = document.querySelector('#message');

            return function displayMessage(message, isError) {
                node.innerHTML = message;
                node.className = isError ? 'error' : 'info';
            };
        }()),
        playSelectedFile = function playSelectedFileInit(event) {
            var file = this.files[0];

            var type = file.type;

            var videoNode = document.querySelector('video');

            var canPlay = videoNode.canPlayType(type);

            canPlay = (canPlay === '' ? 'no' : canPlay);

            var message = 'Can play type "' + type + '": ' + canPlay;

            var isError = canPlay === 'no';

            displayMessage(message, isError);

            if (isError) {
                return;
            }

            var fileURL = URL.createObjectURL(file);

            videoNode.src = fileURL;
        },
        inputNode = document.querySelector('input');
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
    if (!URL) {
        displayMessage('Your browser is not ' + 
           '<a href="http://caniuse.com/bloburls">supported</a>!', true);
        
        return;
    }                
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
    inputNode.addEventListener('change', playSelectedFile, false);
}(window));

<h1>HTML5 local video file player example</h1>
<div id="message"></div>
<input type="file" accept="video/*"/>
<video controls autoplay></video>

video, input {
    display: block;
}

input {
    width: 100%;       
}

.info {
    background-color: aqua;            
}

.error {
    background-color: red;
    color: white;
}