Is Any Way That Is Safe to Display Videos in a Browser

How to serve videos in a website somewhat securely

Long story short, there is no simple solution.

I will say straight up that if there was a way to stop people from downloading videos, every video website would be doing it.

I have thought of a few ways, listed out below, of what you could do to make it not worthwhile for the student/viewer to download the videos.

obscure the URL
change the URL frequently
restrict the number of downloads per IP address/subnet
make them view it in a custom-built "custom-served" video player
use a video streaming service already available

Each are discussed in greater detail below.

Obscuring the URL

You could obscure the URLs like so:

http://mylearningmanagementsystem.com.au/e12d8cd38f00f204e9801998ecc8427e/video.flv

You could calculate a hash of the name of the file itself (or salt and hash, the above is just an example) and use that in a URL.

This could be achieved in such a way that they would be obscure enough, but still bookmarkable and user-friendly for the viewers.

If you wanted to go one step further, you could have video broken up into parts - this is discussed in the custom built section.

Change the URL frequently

With some code, you could set the videos to change URLs every Sunday night at 11.59pm for your timezone. However, any page that you link to would have to be either automatically or manually updated, and that is a hassle in itself (how do you test the code/what if it falls over and you don't realise/things like that).

Even if you get all of that working, any user that bookmarked the page would suffer from link rot.

Restricting the number of downloads per IP address/subnet

With some funky server-side code, you could limit the number of times a video can be downloaded to an IP address (or depending on the user case, a subnet of the IP).

This is not my strong point, but you could look at articles on Dynamic IP Restrictions. The below is an excerpt from the website

Dynamically blocking of requests from IP address based on either of the following criteria:

The number of concurrent requests.

The number of requests over a period of time.

There is also the possibility of doing the same with Drupal.

Make them view it in a custom-built "custom-served" video player

You can go the extra mile and make your own video-management system (which it seems like you are), and serve the videos from your own server (which is what I meant by custom-served) but some programs that have attempted this were flawed like Sony's CD management software or were punishing honest users, like Apple iTunes' FairPlay DRM software.

If you do end up going the route of giving users a program/web service to watch videos and restrict them to an password/encryption key, you could annoy the customers who paid for your content in good faith. This is essentially what all copyright protection systems tried and utterly failed with, because either the program wasn't secured well enough or people simply stopped using it because it was awkward to work with.

When you serve the videos to the users, you could break them up and separate them by chapters, as in the first chapter is one video, the second is another, and so on (like below):

http://mylearningmanagementsystem.com.au/video_title/chapter_01/video.flv
http://mylearningmanagementsystem.com.au/video_title/chapter_02/video.flv
http://mylearningmanagementsystem.com.au/video_title/chapter_03/video.flv

... and you could combine that with the hashing idea in the first section (Obscuring the URL):

http://mylearningmanagementsystem.com.au/e12d8cd38f00f204/8fd3611c40e74c3d/video.flv
http://mylearningmanagementsystem.com.au/e12d8cd38f00f204/92d7f54d09c80436/video.flv
http://mylearningmanagementsystem.com.au/e12d8cd38f00f204/27bd98792bea3103/video.flv

This could have its downsides though:

low internet users who pause the video at the start to let it load, will experience issues (less common a problem now, as the internet is now much faster and easier to access)
if one video is missing, the whole video will be unplayable
how will you manage each link? Will each video name have the same hash or a different hash?
will you have to manually break up each video?

The key point here is that this does make a lot of unnecessary work for you. The next option would be to use a video streaming service that is already available.

Use a video streaming service already available

There are plenty of options out there to host and share your video. YouTube and Vimeo are two of these options. I will explain why I prefer the latter.

Password protection
If you wanted to share the videos only with a specific number of paying people, you can protect your videos with a password on Vimeo. AFAIK, YouTube does not offer this service - it only allows you to select members to view the video.
Not only that, but you can add a bunch of videos to an album (in Vimeo), and password-protect the album, so you only have to change the password for the album.
Keep in mind that you may run into increased support messages like "But is this the current password or the one for last week?"
Set embed settings
You can make the video unable to embed on any page, so that users would have to go to Vimeo directly, type in the password (if you set one above), and view it inside their web browser. AFAIK, you can embed any video from YouTube that you can view.

You will have to keep in mind that a quick Google search revealed that there are heaps of online sites that allow you to download videos from these video-hosting websites. There are even browser addons for Firefox and Chrome.

If your business depended on your videos for monetising purposes and you wanted to go one step further, there are paid streaming services that specialise on content distribution with proper access right management and content protection. One of these services is Brightcove. Excerpts from Brightcove follow:

Brightcove Video Cloud securely delivers the highest quality on-demand and live video experiences to reach your audience—no matter where they are. We simplify delivery to an increasingly complex ecosystem of devices and standards across the web, mobile and connected TVs

... and ...

Protect your valuable content

Ensure your video is safe. Use RTMPe stream encryption and SWF verification to prevent video stream ripping and content theft and ensure that your video stream plays back only in your authorized players.

Fine-grained Access Control

Pinpoint exactly when and where your content is displayed to comply with content licensing restrictions, global launch roll-out schedules or secure behind-the-firewall delivery. The user-friendly graphical interface allows you to restrict access by date, domain, geography, player or IP address. For even greater control restrict access to sensitive materials by IP address range and ensure content is accessible only from within approved networks.

At the end of the day...

If you can view it, you can download it, no matter how much you obscure it.

If there was a way to stop people from downloading videos, every video website would be doing it.

If you had unlimited resources, you could combine all of the techniques listed above to make it not worth anyone's time. But, after all the effort you put in, a viewer could always set up one of many screen capture programs to record all the videos onto their hard drive.

It's up to you, and how vigilant you want to be with your videos. Remember that the effort and time you spend making it harder to rip a video, is proportional to making it harder for regular paying customers to get and use the content as well.

More information:

How can I make a video not downloadable?
Vimeo privacy settings
Video streaming service | Online Streaming Video | Brightcove

Supporting videos in all browsers?

Just use a single video tag and multiple source tags. The browser will choose the proper source.

Ex:

<video autoplay loop class="fillWidth">
    <source src="vid.mp4" type="video/mp4" width="1024" height="768" />
    <source src="vid.ogv" type="video/ogv" width="1024" height="768" />
    <source src="vid.webm" type="video/webm" width="1024" height="768" />
    Your browser does not support the video tag. I suggest you upgrade your browser.
</video>

What is the best way to save video if I am building a site like youtube?

A lot depends on the size and the location of your audience, but in very general terms separating the metadata (name, genre, actors etc information) from the actual video is a good approach.

The metadata typically is stored in a searchable storage like a traditional database, ElasticSearch, etc.

If your site is small and your users local to you and likely to connect over good speed connections then you might get away with simply hosting the videos themselves in a file systems on your server.

For any sort of large scale service, you will actually want to use a CDN and a streaming server.

The CDN essentially takes care of making sure that users in different locations get similar performance by storing copies of your video near the 'edge' of the network.

The streaming server is the 'origin' or the source for the CDN - it will generally support one or more streaming protocols (as different devices or browsers work best with different protocols) and you will most likely want it to support adaptive bit rate streaming, which essentially provides multiple copies of each video encoded in different bit rates, to cater for different network conditions.

It might be worth your while looking at some example streaming servers to get a feel for whether you need to go that way - some popular examples are:

https://www.wowza.com
http://www.videolan.org/vlc/streaming.html