What Happens When You Press Play? Video Infrastructure 101
Millions of people each day watch videos across social media, streaming providers, and websites. Current estimates say that five billion videos are watched on YouTube every day (source).
But how often do we stop to understand all the underlying technology needed to get a single video to play on demand? Today, we’re going to explore what happens when you press play.
Trying to Watch a Single Video
Imagine watching a YouTube video in a browser, a task that billions of people do every day. The average consumer can provide a short list of services that need to communicate in order to get that video to play (your browser, website, internet service provide). In reality, the stack is much, much deeper.
A cloud service like YouTube is not actually a single “website.” While we may all reach YouTube through a single URL, there are thousands of individual servers that work together to store its video libraries. When you press play on a video, you are sending a signal to YouTube, who then fetches that video from one of its servers or from a content delivery network (CDN) that has that video file cached.
Let’s dive deeper into these three distinct parts:
- Client: What you own and control
- Server: What the service manages
- Content Delivery Network (CDN): A local cache of the content
Client
Each client looks very different. For instance, a person may watch YouTube videos vertically on their Android phones with no sound at the same time someone else may expect 4K streams on an 80” OLED TV. In both cases, a service must understand the request (I want to watch Video A), and also who is making the request (the resolution, screen orientation, connection quality, and more).
Think of how many combinations there are of device, operating system, browser, and signal strength! Streaming providers must evaluate these parameters and balance providing high-quality videos with the fast load times that consumers expect.
Server
The “server” or “backend” refers to the infrastructure that allows the correct video to be retrieved and played. For example, YouTube (which is owned by Google) runs on the Google Cloud Platform. There are thousands of individual servers that work together to receive and fulfill requests that users make (e.g., client makes a request to the server and the server responds to that request).
In another example, Netflix has adopted Amazon Web Services (AWS) as their cloud infrastructure provider. Every time you navigate through Netflix’s menus or search, you are interacting with Netflix via Amazon Web Services.
CDN
The content delivery network, or CDN, is the last crucial piece of the puzzle. Today, video has proliferated into every part of our lives: We have videos in the background of websites, we can send videos and GIFs between friends, and modern smartphones are powerful enough to watch (and record!) 4K video.
And when you press play on a video, the CDN fires into action to provide seamless video playback.
A content delivery network is a global mesh of servers and databases that work together to deliver content. Instead of connecting to a single server (say, in New York), a CDN replicates the same video files across hundreds of servers across the world.
This replication does a few things: First, the CDN places the files physically close to you. Instead of connecting to a server thousands of miles away, you can connect to one nearby, thus cutting down the latency. Second, the CDN creates copies of these files so that all of the world’s traffic is not being sent to a single server.
By routing requests to nearby servers, CDNs allow companies to reach much more scale while providing a better experience to the end customer.
Conclusion
When you press play on a video, you are kicking off a very detailed sequence of events. We touched on three main pieces: client, server, and content delivery network. There are also many more nuanced pieces — like how videos are compressed for storage and transfer, or how a browser decodes a video file into audio and images.
So far, we have discussed a centralized video infrastructure. In other words, the server and CDN components are controlled by a handful of vendors. VideoCoin imagines a decentralized future.
The company plans to open up the market by allowing anyone with spare resources — bandwidth, compute, or storage — to receive payment in exchange for their work in the VideoCoin Network. The VideoCoin Network would dramatically reduce cost and allow for the next generation of video companies to built on top of its platform.
Come join our conversation on Telegram: https://t.me/videocoin
