A primer to the technology and terminology behind video distribution via the Internet
Even before the Apostle Paul’s evangelical travels throughout the Roman Empire, ministries have been searching for ways to extend their reach to greater and greater numbers of people. It’s not surprising, then, that some of the most exciting new technologies involve ways to distribute video much faster and cheaper than ever before via the Internet. Often, these technologies are rolled up into the term IPTV, or Internet Protocol Television. Basically, this term means video that uses the way data is transmitted over the Internet as the means of transmitting video to the viewer instead of traditional over-the-air broadcast, satellite or cable technologies.
In industry terms, however, the term IPTV has come to mean something more specific, which has caused some confusion – particularly when someone who wants to employ the technology is trying to communicate their needs to technical professionals. Even the underlying technologies have terms that are often confused with one another – even by industry professionals. This makes it important to both understand what the terms mean to professionals and to understand the slightly differing technologies involved in distributing multimedia content via Internet Protocol. While these technologies can certainly transmit audio content as well, this article will specifically address video distribution.
There are three basic concepts to understand. The first is what is meant by “IP” and why it is distinguished from the more traditional transmission technologies. The second is based primarily on how, where and with what device the viewer receives and watches the video content. The third is specific to the way the content is being transmitted and digested by the user. Each of these has its own specific characteristics, as well as strengths and benefits. Understanding each will enable a better understanding of the right platform and technology to achieve a specific goal.
Defining IPTV and Other Internet Video
Obviously, everyone knows what TV is, but what does the IP in IPTV stand for and why is it different from broadcast or cable television distribution?
IP simply stands for “Internet Protocol”, which is the standard platform for data to be distributed over a network of connected computers and routers. So why isn’t all online video called IPTV? The specific term IPTV has come to be defined as the delivery of content via Internet Protocol to a traditional television. Until recently, the only way to do this was to use some sort of set-top box (like a cable converter box) to connect to the network and convert the content signal into something the television could display. There are several companies that have developed set-top box solutions to do this. They are most often closed networks, however, so the only content that is available on a television is content that is a part of a network put together by that company. A user would not be able to watch any video content on the Internet from their television with this solution- just the content that is made available by that IPTV company. One unique example of this type of solution is actually the XBox gaming console made by Microsoft. While it was made as a video game platform, it also works like an IPTV set-top box. It connects to content made available by Microsoft for watching with the XBox.
Recently, however, television manufacturers have begun making televisions with network connections and software installed that can access the Internet to get other video content. These use something called RSS, (Really Simple Syndication), to find content. With an RSS reader built into the television, any video content, such as video blogs, can be accessed by the television so long as the video is distributed in an RSS feed. The development of this technology is in its infancy, however, and very few people have such televisions or know how to use them in this way.
When the content is distributed over the Internet and watched on a computer screen as opposed to a television, then the technology is not called IPTV. There is not a universally accepted name for this type of technology, but sometimes this is just called online video or Internet TV. The main difference here is that the content is typically open and accessible by any computer connected to the Internet. It may be free content or paid content by subscription (pay-per-view).
A third type of video content distributed by Internet Protocol is mobile video (sometimes called Mobile TV). This is separated from online video because it normally requires the content to be distributed (or redistributed) by a cellular carrier. There is a current effort in the cellular industry to open up the networks that cell phones use to connect to the Internet to allow for any online content to be accessible from cell phones. For now, a cell phone user (that is, not a Pocket PC) on a specific cellular carrier’s network can usually only access the video content that is on that network.
To Stream or Not To Stream
It is important to understand the differences between these three types of distribution technologies – IPTV, Internet TV and mobile video – because each has strengths and weaknesses to consider when determining how one wants to distribute video content via the Internet. There is an additional choice to be made, however, which is just as important, and it involves how the content is sent to these types of technologies. Most often, video content is either streamed or downloaded. Again, which technological solution is deployed depends on the specific needs of the project, and how it is consumed by the end users who will watch the videos. To complicate things, there is a technology called progressive downloading that is similar to streaming, and there is an ongoing debate within the industry whether progressive downloading should be called streaming. The technology is different between the two, however, so they are distinguished as separate technologies for the purposes of this article.
Streaming is a technology that employs a special type of web server that is set up to stream video content from an encoder. An encoder is software running on the server that sends the content over the network at a specified rate (or speed) of data transfer. This rate is called the bit rate.
For example, if a video is encoded at 200 kilobits per second (or 200 kbps), then a streaming video server will send that video to the user at that speed – 200 kbps – and the user will not actually be storing any of that information on their own computer. There is, however, a buffer which will temporarily save some of the data on the user’s computer so as to ensure that the signal is not interrupted if the connection to the server is not 100% consistent. The bit rate is important because it directly affects the quality of the video. The faster the bit rate, the higher the quality of the video will be for the person watching it. As a point of comparison, DVD-quality video is 5 Mbps (megabits per second), while a Blu-ray Disc quality is 54 Mbps – much faster than almost any typical Internet connection available to most users.
Downloading (or progressive downloading) works differently than streaming, in that it typically does not require a server to serve the content to the user. Instead, the media player software that is on the user’s computer simply converts a file that resides on the web server, and pulls the entire file down to the user’s computer. This usually allows the user to save the file to their computer and watch it later, or simply watch it and not save it. If the user watches the video from the web server without saving it, it is called a progressive download. It is called that because as the player begins playing the video, the file is being downloaded and saved temporarily on the user’s computer. The difference between this and streaming with a buffer is that the content is not being sent to the user’s computer at a specific rate. Rather, it is being sent as fast as possible according to the networks both the server and the end user are on, and the maximum amount of connectivity (or bandwidth) available to each of them.
The speed at which the content is sent is the main and most important difference between streaming and progressive downloading. This is important because it affects both the quality of the experience to the person watching the video, and the amount of bandwidth that is used to deliver the video to that person. If the person watching the video has a solid and reliable high-speed Internet connection (such as cable or DSL of at least a 1 Mbps download speed), then most streamed content of 300Kbps or lower will be delivered smoothly and without interruption to the user, as long as the network being used to deliver the video has enough available bandwidth. If the bandwidth is reduced at either the network or the user’s end however, the video may “buffer” or pause while the data catches up. A progressive download, on the other hand, shoves more data to the end user as fast as possible, and has a better chance of staying ahead of where they are in the video.
The other consideration is, using progressive download as the means of distribution is not as efficient and can be more costly. This is especially true if the video is long, and the average person watching does not watch the whole thing. If a person watches only the first 10 minutes of a 30-minute video, they will have downloaded a lot more than ten minutes (perhaps the whole file) with a progressive download, while streaming would have only delivered what was watched. Therefore, more bandwidth was used by the server. As bandwidth is a commodity and networks charge according to what was used, the progressive download may have been as much as three times more expensive than if it had been streamed.
There are, however, technologies that can be employed to cut down on bandwidth consumption for both streaming and downloading. These are called peer-to-peer or peering technologies. They will actually use the user’s available upstream bandwidth (the part that sends out to the Internet) to pass on part of the content to another user. Since it is using the user’s bandwidth as opposed to the network’s, there is no additional cost to the content distributor for that bandwidth.
The final consideration between streaming and progressive downloading is whether the content is live. Live content must be streamed, as there is no existing file for the user to download. Live streaming requires an encoder at the content source, and delivers the content as it is being encoded to the network in real time. The only delay is the existing latency of the network being used. This latency can be anywhere from a few seconds to a minute or more depending on the network.
Choosing the Best Technology
Whether the content is delivered over IPTV, Internet TV or mobile TV, and whether it is streamed or made available for download, depends on the application. Here are a few examples of applications and suggestions for the best option to use.
A congregation wants to distribute its service to another location where many people will be watching together, such as another church or auditorium.
Stream the content from an encoder at the source over an IPTV network. On the other end, a set-top box would receive the content and send it to TV screens, or a large-screen projector. IPTV is a particularly good solution for secure distribution from one source to one receiver.
An evangelist wants to reach a diverse audience around the world in real time and solicit feedback (from phone calls or email or online chat) from the audience.
Stream the content from an encoder at the source over Internet TV. Set up a website where people can “tune in”, watch the content and call, email or chat with the host. The content can also be made available over a mobile carrier’s network for people to tune in on their cell phones. Streaming will enable live distribution to the widest possible audience online and around the world.
A church has a number of great sermons, concerts and other content recorded, and they want to make it available to a wide audience.
Make the content available online for download and viewing with progressive downloading by putting it up on a website where people can watch or download the content freely. If the content is sold or some sort of registration is desired, an e-commerce solution (similar to iTunes) could be employed, or the downloads could be placed behind a log-in form to collect more information about those that are downloading the content.
The most important thing to consider when exploring new media distribution options is: what is the desired goal for making the content available? If the goal is to generate sustainable revenue, reach a wider audience, share the content with specific audiences, or all of the above, determine which technology and platform is best to deliver that goal. One unifying characteristic of these options is that they are all responsible for helping to democratize media and make content more efficiently and effectively distributable than ever before.