Streaming media online has come a long, long way in the past decade or so.
Remember the old days of staring at a little loading bar for minutes before ever hearing or seeing the media you wanted to play? Well (thankfully) those days of lengthy ?buffering? are over. In fact, you probably haven?t seen the word buffering very much over the last few years. Or at least, it?s probably not on your screen for very long.
These days the audio and video we access over the Internet comes to us at a rapid rate. We have the ability to watch anything from short clips to full movies, and we can listen to anything from the local radio stations we know and love?to the online radio stations that tailor the music we stream to match our own, unique tastes.
Thanks to quick streaming audio and video, many of us spend hours a day exploring media online. Our computing devices give us access to anything from popular bits of media to extremely obscure audio and video.
But how exactly does that media get to us? And what makes it so fast these days?
Well, streaming audio and video may seem complicated (or even magical to those of us that remember the early days); but in fact, there are just a few steps needed to take media from a video or audio file, to a web server, to a media server, to your device, and then straight to your eyes and ears?all in seconds.
This post will explain how your streaming media gets from here to there, and it will even give you some tips for getting your own media out there on the vast world wide web.
Streaming Media: The Basics
Streaming audio and video works in much of the same way as good, old-fashioned information exchanging:
For example, when you watch and listen to a concert in person, the visual and auditory signals you pick up on have to be read by your brain and decoded. Although to us this seems to happen instantly, we see what we see and hear what we hear all because of a process involving waves of information that quickly travel to our brain to let us know what?s going on. Thus is the case with streaming media.
In the real life case, sound waves and visuals are intercepted by receptors (yours eyes and ears). Then the information your senses pick up on travels to your brain, gets decoded, and the experience of being at a concert is realized.
In the case of streaming media, the video and audio data you access on your device is always stored on a media server?just like the website you find it on is stored on a web server.
To experience streaming media, the device you?re using?much like your brain?needs to have the receptors to decode that data with. In order to decode streaming media, your device must have a plugin for your web browser (or a stand-alone player).
Media players are file readers that serve to decode and display the data you request, and each player supports a different type of file format. The four main players are:
– Adobe Flash player for .flv and .swf (animation) files
– Quick Time (for Apple) plays .mov files
– RealNetworks Real Media plays .rm files
– Windows Media (for Microsoft) plays .wma (Windows Media Audio), .wmv (Windows Media Video) and .asf (Advanced Streaming Format)
A lot of times these players cannot decode the types of files that are built specifically for their counterparts. So sites you access may pick a player for you, prompt you to download one you don?t have, or they might give you an option of which player you?d like to access their media on.
The Ingredients for Streaming Media
So far we?ve explained the basic ingredients for streaming media:
On one end you need a web server used for storing the website, which when prompted sends a message to a streaming media server requesting a specific media file that exists on that website. On the other end you need a device with which to access that server and a receptor (media player software) that can decode the file.
The ingredient in the middle is?of course?the Internet access gained through underground Internet cables that are necessary to transmit the information from a server?s datacenter to your location.
Next, we?ll explain how streaming files get produced so that users all around the world can experience them through the streaming process.
The Evolution of Streaming Files
Streaming files need to be stored on a server and accessed instantly, so they?re pretty small and compact.
On the contrary, the best quality streaming files usually begin their run as very large, high quality files. These ?raw files? are analog recordings or digital files that have not yet been compressed or distorted.
Once the compression process starts, bad quality files only get worse. If your video is blurry or of low quality?or your audio is hard to hear?once you compress the file these qualities will be much worse. That?s why it?s so important to start with a very high grade, large file before compressing it down to streaming media. One tip is that you can reduce a file?s size before lowering its quality, yielding a better end product:
Reduce the Picture Size:
Most streaming videos aren?t meant to be played on a big screen. Instead, they play in a smaller window on a device. Usually if you stretch a streaming video, you?ll instantly see a drop in quality. For example, if you view a homemade video on YouTube, the picture is way fuzzier and of much lower quality if you select full screen mode as opposed to the smaller window.
Reduce the Frame Rate:
Lowering the frame rate can increase the quality of your streaming media. All videos are really just multiple frames (or pictures) moving at a rapid rate to convey action. If you slow down the frame rate of your online video, or remove excess frames, you?ll have fewer frames and less data needed to recreate the video.
You?ll Need Codec Software:
Codec, or compression/decompression software, takes the steps needed to discard unneeded data in order to make the file more compact.
Codecs vary in type and different codecs yield specific types of files that work in tandem with specific streaming media players. Some codecs help you create files that that stream at various bitrates, this means they work for slower connections (like those using dial-up modems with lower bitrates) as well as reliable broadband connections that?with the help of lots of bandwidth?can handle high bitrate files.
After a media file has been edited, it?s compressed and encoded. Next, that file is uploaded to a server.
From Server to Screen
Streaming servers deliver the compressed data and files to your computer with the help of a web server. The process, in its simplest form, goes a little like this:
– First you access a web page, which is stored on a web server in a datacenter
– Then you click the file you want to play/use on that site
– Next, the web server sends a message to a streaming server, notifying it of the file you?ve requested
– The streaming server then sends the file directly to you, without going back through the web server
Like most things in computing, the information makes its way to you governed by a set of protocols.
Protocols determine how data is transmitted between various computing devices and over networks. Well-known types of protocols include:
– TCP/IP: Transfer Control Protocol
– HTTP: Hypertext Transfer Protocol
– FTP: File Transfer Protocol
– SMTP: Simple Mail Transfer Protocol
Protocols used to stream audio and video include:
– RTP: Real-time Transfer Protocol
– RTSP: Real-time Streaming Protocol
– RTCP: Real-time Transport Control Protocol
The protocols above are used as an added layer to general protocols in order to stream data in real-time to where it needs to go.
After explaining the basics, hopefully your understanding of how streaming audio and video work is a little clearer.
Luckily we don?t have to think about what goes on behind the scenes when we stream audio and video online. But hopefully this post gave you some insight as to how the streaming media you access gets from A to B so quickly.