简单的回答,

你不能

如果他们正在看你的视频，他们已经有了

你可以让他们慢下来，但不能阻止他们。

+1简单和跨浏览器的方式: 你也可以用css z-index和不透明度把透明的图片放在视频上。 这样用户将在上下文菜单中看到“另存图片为”而不是“保存视频”。

如果你正在寻找一个完整的解决方案/插件，我发现这个非常有用 https://github.com/mediaelement/mediaelement

作为客户端开发人员，我推荐使用blob URL， blob URL是一个引用二进制对象的客户端URL

<video id="id" width="320" height="240"  type='video/mp4' controls  > </video>

在HTML中，让你的视频src为空， 在JS中使用AJAX获取视频文件，确保响应类型是blob

window.onload = function() {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', 'mov_bbb.mp4', true);
    xhr.responseType = 'blob'; //important
    xhr.onload = function(e) {
        if (this.status == 200) {
            console.log("loaded");
            var blob = this.response;
            var video = document.getElementById('id');
            video.oncanplaythrough = function() {
                console.log("Can play through video without stopping");
                URL.revokeObjectURL(this.src);
            };
            video.src = URL.createObjectURL(blob);
            video.load();
        }
    };
    xhr.send();
}

注意:大文件不建议使用此方法

EDIT

使用跨源阻塞和头标记检查来防止直接下载。 如果视频是通过API传递的;使用不同的http方法(PUT / POST)来代替'GET'

简单回答:像youtube那样加密链接，不知道怎么做，不如问问youtube/谷歌他们是怎么做的。(以防你想直奔主题。)

I would like to point out to anyone that this is possible because youtube does it and if they can so can any other website and it isn't from the browser either because I tested it on a couple browsers such as microsoft edge and internet explorer and so there is a way to disable it and seen that people still say it...I tries looking for an answer because if youtube can than there has to be a way and the only way to see how they do it is if someone looked into the scripts of youtube which I am doing now. I also checked to see if it was a custom context menu as well and it isn't because the context menu is over flowing the inspect element and I mean like it is over it and I looked and it never creates a new class and also it is impossible to actually access inspect element with javascript so it can't be. You can tell when it double right-click a youtube video that it pops up the context menu for chrome. Besides...youtube wouldn't add that function in. I am doing research and looking through the source of youtube so I will be back if I find the answer...if anyone says you can't than, well they didn't do research like I have. The only way to download youtube videos is through a video download.

Okay...I did research and my research stays that you can disable it except there is no javascript to it...you have to be able to encrypt the links to the video for you to be able to disable it because I think any browser won't show it if it can't find it and when I opened a youtube video link it showed as this "blob:https://www.youtube.com/e5c4808e-297e-451f-80da-3e838caa1275" without quotes so it is encrypting it so it cannot be saved...you need to know php for that but like the answer you picked out of making it harder, youtube makes it the hardest of heavy encrypting it, you need to be an advance php programmer but if you don't know that than take the person you picked as best answer of making it hard to download it...but if you know php than heavy encrypt the video link so it only is able to be read on yours...I don't know how to explain how they do it but they did and there is a way. The way youtube Encrypts there videos is quite smart so if you want to know how to than just ask youtube/google of how they do it...hope this helps for you although you already picked a best answer. So encrypting the link is best in short terms.

PHP将html5视频标记和一个会话一起发送，其中键是一个随机字符串，值是文件名。

ini_set('session.use_cookies',1);
session_start();
$ogv=uniqid(); 
$_SESSION[$ogv]='myVideo.ogv';
$webm=uniqid(); 
$_SESSION[$webm]='myVideo.webm';
echo '<video autoplay="autoplay">'
    .'<source src="video.php?video='.$ogv.' type="video/ogg">'
    .'<source src="video.php?video='.$webm.' type="video/webm">'
    .'</video>'; 

现在PHP被要求发送视频。PHP恢复文件名;删除会话并立即发送视频。此外，所有“无缓存”和mime类型的头必须存在。

ini_set('session.use_cookies',1);
session_start();
$file='myhiddenvideos/'.$_SESSION[$_GET['video']];
$_SESSION=array();
$params = session_get_cookie_params();
setcookie(session_name(),'', time()-42000,$params["path"],$params["domain"],
                                         $params["secure"], $params["httponly"]);
if(!file_exists($file) or $file==='' or !is_readable($file)){
  header('HTTP/1.1 404 File not found',true);
  exit;
  }
readfile($file);
exit:

现在，如果用户复制url在一个新的选项卡或使用上下文菜单，他将没有运气。