Podcast Unwrapped
In recent years the term Podcast has been uttered from pulpits and platforms in worship facilities around the world to promote the media available on the church's website. What does Podcast really mean? How can it help your church? Let's unwrap the term, build a technical context around it, and determine its best uses in your church.
Brief history of Podcasting
Weblogs-known today as blogs-started as textual daily or periodic online publications of a topic, and sometimes a rant. When technology arrived that permitted mp3 files to be created and uploaded easily to a central location, and just as easily downloaded and listened to by another party, this form of recording and distributing audio became a popular alternative for many bloggers. Audio-blogging was born.
On October 23, 2001, Apple introduced the iPod, which made it easier to download your favorite audio blog or "show" and listen to it on the beach, in the car, jogging or while doing chores around the house. The downside to this technology was that you had to continually go to the Web or blog site to see if there was new content available for download.
Two technologies emerged in the late 1990s that lead to the syndication of Web content. The first was eXtensible Markup Language (XML) and then a key derivative work called Really Simple Syndication (RSS).
In 2004, Dave Winer, one of the creators of RSS, and MTV VJ Adam Curry worked together to create and popularize what is known today as Podcasting. Podcasting is the syndication or automatic downloading of a show or audio blog that you subscribe to. The audio blogs are created and distributed to subscribers so they can listen to them when available. The term Podcasting was taken from the idea of broadcasting syndicated content to iPods for playback at a later time. Listening to or viewing a program after it was created or originally aired is often referred to as time shifting.
The difficulty today is that the term Podcasting becomes synonymous with viewing time shifted or video on demand content over the Internet. In other words, if I can go to the Internet and listen to or view digital media on a church website, this is commonly considered Podcasting, but this is not the case.
Streaming Definitions
To further unwrap the generic use of Podcasting with the listening to or viewing digital content on or from the Internet, we need to take a closer look at three key media technologies: streaming, downloads, and progressive downloads.
All three of these technologies are defined in contrast to real time delivery. Real time delivery just means you are viewing an event as it happens; however, the event doesn't have to be live. When thinking about an event that is real time but not live, consider your favorite network television show. It is shot and edited weeks if not months before its premiere on the network. When it is played for the first time on the network it is viewed in real time but it isn't actually live.
A real time or live stream is not saved to local memory or storage. In a live production you have a video camera capturing images of the scene at an approximate rate of 30 images or frames a second. For live viewing on the Internet you have to convert the video frame into a data packet; this process is called encoding. If a frame or packet is missed, it is gone. From the perspective of the Internet viewer, if a frame or packet is missing or dropped you will get black video until a good frame or packet can come through. This sometimes occurs on the user end if your local connection can't keep up with the live stream of packets.
Streaming
Streaming media is a real-time signal transmitted through the Internet in data packets. In its simplest form it is a camera connected to an encoder that turns the video signal into data packets to be transmitted over the Internet. A computer or digital media device takes the data packets and decodes them into a video you can view using a media player. Typically you can't pause, fast forward, or rewind a live stream because it is happening in real time.
One thing to note here is that Progressive Downloads can also have smaller bandwidth because you don't have to provide real-time video for all of the users concurrently. Instead, the downloading will just take longer for each user to download as the number of concurrent users goes up.
This is not the case with real-time streams, because you need to supply the bandwidth for all of the connected users. For example, if you have 150 viewers using a bitrate of 220k for one hour it would require 13.84GB bandwidth. There aren't many locations that can provide this amount of bandwidth directly from their facility; therefore, you will need a Content Delivery Network (CDN) service to provide the bandwidth for all the people streaming a live event.
Download-
the Heart of the Podcast
Let's continue with the Podcast discussion for a moment. As mentioned at the beginning of this article, the core of a Podcast is an mp3 or similar file format that is completely downloaded to your computer or portable device. Once it is downloaded, the file plays from the player's local memory or storage. The file has to be completely downloaded before it becomes playable on your media device or computer's media player.
Progressive Downloads
The most widely used technology on the Internet today is Progressive Downloads. YouTube videos, Netflix shows and other media that you view over the Internet are technically Progressive Downloads, although they appear to be in real time. It would be difficult to have the success of media on the Internet without progressive downloads because of the various bandwidths available where the media is actually consumed.
Progressive downloads provide a benefit over downloads because you don't have to download the whole file before you can view it. The encoded speed vs. the file transfer determines the performance of a progressive download. This is often referred to as the "progress bar race" in your media player. If the transfer is slower than the encoder, you will experience several stops and starts of your video. If you have large download bandwidth, you will experience what appears to be real-time streaming.
Putting it All Back Together
Digital technology has provided wonderful tools for effective communication, but it has also brought us a number of challenges. There are more and more platforms to deliver our message, too. This expands the number of technologies we have to understand. From a communication standpoint we need to determine when and how we want to engage our audience, which requires more planning and execution time.
Blogs are exceptional for interactive communication using text, audio and video. The front end of blogs requires knowledge in XML, Cascading Style Sheets (CSS), and dynamic web technologies. The benefit is providing interactive communication for a richer dialog.
Webcasts use live streaming technology, plus you can add Instant Message (IM) technology along with other user feedback tools like polling/voting about topics for live interactive programming.
Podcasting provides a number of avenues for communication, for example daily devotionals, bible study series or a children's radio show to listen to on the way to school.
Traditional live broadcasting of a worship service or other special programming can be done with live streaming technology as long as you have a good encoder, bandwidth, and-depending on the number of viewers a Content Delivery Network (CDN).
All the tools we have available to us today take planning and collaboration between the technology suppliers and the content creators to provide a production value that is meaningful to the intended audience.
In the next issue of Church Production we will not only go deeper into various technologies discussed in this issue, but we'll also provide some tips and tricks for increasing production quality when using them.
