Thursday, December 5, 2013

Communications and Security: YouTube

Source: http://www.rudyhuyn.com/blog/wp-content/uploads/2013/05/YouTube1.png



My focus for this post will be about communications and networking, primarily, YouTube. YouTube is a video streaming site that started in 2005. In the beginning, YouTube was a rather "dumb" streaming service that would simply send the video data in one big chunk, so there was no detection of slow internet speeds or error correction of lost data. You would essentially just download the whole video and play it.

Now however, YouTube's goal is to be able to give the user a seamless viewing experience by never having the rotating wheel, meaning that the video is buffering, appear. In order to do that, YouTube now sends the video in pieces, allowing the stream to decide during its transmission, "Hey, the video isn't able to keep due to the internet", or "Hey, the video is transferring very fast, I can up the quality", and so on.

When you upload a video to YouTube, it actually breaks those files up and creates different resolutions of it. I was shocked by this because that's a lot of data to store! If you send in a 1080p resolution video, it now has to store a 720p, 480p, 360p, and 240p versions of it too. On top of that, they also store different file formats of it so that it can be used on many different platforms: MP4, 3GPP, WMV, etc. In each of those versions, they then chop it up even more, as mentioned earlier, into a couple seconds long. This is how they are able to gather all the different factors that can make your stream out of whack, analyze it, and then send out the correct quality video to your bandwidth capabilities.

Here's a great video that goes a little more in depth on how YouTube works: http://www.youtube.com/watch?v=OqQk7kLuaK4


If you've read past articles of mine, you'd recognize this channel. I really enjoy the content they put out since it's all related to computers so if you like the video, you should subscribe to them!

3 comments:

  1. Hello, Steve. I really like your post on Youtube! Actually, one of my projects deals with adaptive media streaming, so I found your post very fun to read. Youtube's service is a very good model for adaptive streaming, as it will collect client information and then make decisions on streaming parameters. This method takes a lot of storage space, though.
    I like the fact that you conveyed the main idea in really simple words which makes the whole post easy to read, but it would be better if more technical references are included.
    Good post overall!

    ReplyDelete
  2. Hi Steve,
    So your topic is about video communication, or network file sharing, right? Good introduction about algorithms in YouTube video sharing.
    In you post, you have raise the example of how YouTube share video files past, and also you compare it to the current algorithm, this would make me figure out the advantages/outcomes the new "piece" method brings and obviously this would make your post easy to understand. It's a nice post.
    I still think that if it's better if you change your title and make it clearer. Although there might be some requirements in title, security should not appear becaues I don't think you talked about it. But anyway it's a very good blog!

    ReplyDelete
  3. Hello Steve,

    Great post. I have not really thought about how Youtube works even though I use it regularly. I also loved the source you used. They certainly explain the subject well and I will look further to the other videos that they posted. It is quite interesting how they store different versions of the same video, different file formats and resolutions, and how they chop up the data to make it more “digestible”.

    ReplyDelete