Technical history of podcasting

Roots: Files, software, hardware and bandwidth

Podcasting is more than a subscription-based Web broadcast that automatically detects and downloads new files. Today, for more than 500 thousand creators across the globe, it’s an art, a career and a passion.

Although podcasting has burgeoned in the 21st century, its origins date back to the early 90s. The genesis of podcasting lies in the introduction of digital files known as MP3s. The MP3 format, which originated in 1991, allowed audio to be compressed into a much smaller file while maintaining sound quality. (Mp3 History)

The small file size of the MP3 without sacrificing audio quality was a significant breakthrough. A typical audio recording can be converted into a number of sized mp3 files depending on audio quality. The worst sound quality results in the smallest possible mp3 while the best quality results in a file that is still 10 times smaller than the original uncompressed recording. A typical MP3 is compressed at a 10:1 ration, resulting in a 5 MB file for every 5 minutes of audio.

The MP3 format did not become widespread until 1997 when the Windows application WinAmp was released. Created by Justin Frankel, the founder of Nullsoft, WinAmp made it easy for music enthusiasts to exchange and listen to audio on computers. The small size of MP3 files enabled widespread distribution via file sharing applications such as Napster and on wide-area networks such as university dormitory networks.

The popularity of MP3s took off in 1998 when Eiger Labs released the first portable MP3 player called the MPMan. This first MP3 player was flash-memory based and could store 32MB of MP3 files. 32 MB of storage resulted in roughly 32 minutes of good quality audio.

Dial-up access does not offer the bandwidth to download large mp3 files in a timely manor. As broadband Internet access became mainstream, larger files such as mp3s could be downloaded within minutes, rather than hours.

Broadband entered the mainstream in 2001, when it began to grow at a faster rate than dial-up Internet access. In addition, Apple Computer Inc. launched the most recognizable media player, iPod, alongside its iTunes application, allowing iPod users the ability to purchase and download music from the iTunes Music Store. By the end of 2001, all of the pieces of the puzzle were available; they just needed to be put in place.

Syndication: Putting it all together

Syndication is the heart and soul of podcasting. Though syndication is not the only way in which podcasts are consumed, it is the method that facilitated the transfer of small audio files seamlessly over the Internet for use on computers and other portable audio devices.

Syndication gives podcasters the ability to share content over the Internet in a subscribe-able manor. Typical syndication involves the podcaster to write content in segments called posts on web blogs. The podcaster will attach media to these posts so they can be syndicated to the podcaster’s subscribed audience. Subscribers will receive the latest posts with the attached media.

Syndication of podcasts is achieved by RSS – Real Simple Syndication – feeds. A feed is an XML-formatted file that specifies information about a podcast or blog, and RSS is the most common specification of XML used. In 1999, Netscape developed RSS version 0.90 for use on the website. Most of the syndication work that followed came from Dave Winer, who pioneered the development of weblogs, syndication (RSS), podcasting, outlining, and web content management software that influenced the development of Userland Radio. In December of 2000, Winer took RSS feeds one step further when he drafted the RSS 0.92 specification.

“Keep in mind this was 2000, before the world-wide leap in the number of Broadband Internet connections,” notes Todd Cochrane, President and CEO of RawVoice Inc. “Winer’s analogy was that it was taking longer to download video than it was to play it, and many times the video was poor quality and you really did not know what you were going to get.”

The RSS 0.92 specification allowed for associating media files within the RSS feed. In September of 2002, Winer drafted the RSS 2.0 specification, adding support for namespaces. Namespaces allowed additional information to be added to feeds without requiring changes to the original specification. The addition paved the way for the RSS feed format to be easily extended and adopted by many in the industry. The most notable namespace found in RSS 2.0 feeds is the iTunes namespace.

In October 2003, the first demonstration of the potential for syndicating audio through RSS was made during the BloggerCon held at Harvard University. Kevin Marks, a long time blogger and key developer of the Technorati blogging search engine, demonstrated a script that downloaded RSS enclosures. Following the conference, Adam Curry, a former MTV VJ turned podcaster who hosts the Daily Source Code podcast and founded PodShow Inc., offered his blog readers a script called RSStoiPod that moved MP3 files from the Userland Radio website to the iTunes application. The RSStoiPod script was later open sourced and called iPodder.

“Curry’s simple Apple script lit a fire for the development of podcasting that is in full swing today,” Cochrane says.

The iPodder script influenced many developers and by fall 2004 the first graphical application called iPodderX (now known as Transistr) was released. Soon after, another application called iSpider was quickly renamed iPodder (now known as Juice) and distributed under an open source license.

In June 2005, Apple released iTunes version 4.9, which included podcast subscription support, a podcast directory listing within the iTunes Music Store and tools to edit MP3 attributes. Apple also marketed its GarageBand application as a tool to assist podcasters in creating content, and later in the year released iPods capable of playing video podcasts.

By September 2005, Google search results found more than 100 million hits on the word podcast. By the year’s end, podcast was chosen “word of the year” by the New Oxford American Dictionary.