The delivery of a positive web video experience starts with understanding how a video moves from the web server to the user's browser. To understand this concept we visit an old sawmill.
- [Instructor] Before we start encoding video, it is really important for you to understand how video gets from here to there, in this case, from the web server to your browser. Though I could get all technical, let's try something different, and visit the site of an old saw mill, to help you understand the process. Thus, the waterfall. Where we are is Walter's Falls, just outside of Owen Sound, Ontario. It is the site of an old saw mill, feed mill, and wooden mill, that was founded over 160 years ago.
So what, you may ask, does a waterfall have anything to do with web video? In a word, everything. We will start the explanation with this pond behind the falls. The Doghead River flows into this pond, but it is large, simply because, there is a dam that I'm standing on, that controls the flow of water to the waterfall. Think of the water in this pond, as the data for your web video, and the pond itself, as your web server.
When a user opens the page containing your video, that data flows to your browser, much like the water in this mill race, that flows to the edge of the waterfall. This mill race is your internet connection, and I usually refer to it as the pipe, because, data flows like this water into your browser. You will notice, the mill race widens quite a bit, once the water or data leaves it. When the water leaves the mill race, it encounters the edge of the waterfall, and pools behind it.
When the water fills the pool, over it goes. That pool is the browsers cache. With video, that cache needs enough data to start playing the video. With that pool, it needs enough water in it to start going over the falls. As long as the flow rate of the water from the mill race into the pool is constant, the water goes over the falls at a constant rate. When creating web video, you need to keep an eye on the pipe, or in this example, the amount of water flowing into the pool behind the waterfall.
Here's why. Let's now say that the mill owner reduces the flow of water from the mill race to a trickle. The water level in the pool drains, and the waterfall stops flowing, until there is enough water in the pool, to start flowing again. The volume of the water in the pool lowers, the pool level goes down, the waterfall stops. The pool fills, the waterfall starts, and so on, and so on. That is exactly what happens, when a video starts and stops.
The browser cache empties, the video stops, the cache refills with the video data, and on, and on. And what does the viewer do? Exactly what you would most likely do, move to another site, because you have had a very bad experience. This nasty situation is avoided, when the video is encoded. And that is the subject of the next exercise, as we explore the Adobe Media Encoder.
- Key video formats used to publish on the web
- Encoding video that's optimized for online delivery
- HTML5 native video embedding and interaction
- Styling video components with CSS
- Captioning video
- Preparing video for social media
- Using Dynamic Link