Intro to PodcastingGreat Lakes Broadcasting Conference

14 March 2006

Harold Beer - WKARGreat Lakes Broadcasting Conference

14 March 2006

Podcast• a portmanteau

• coined from iPod and broadcasting in 2004• New Oxford American Dictionary - word of the year

2005• Defined: a digital recording of a radio broadcast or

similar program, made available on the Internet for downloading to a personal audio player

got content?

Elements of a podcast

• Metadata – information about information• ID3 tags – best-known ‘standard’• Song title, artist, album, and so on; But what about

radio programs, or news features?

• Audio file Usually mp3, but could be Windows Media, Ogg-

Vorbis – precluded by convention and the embedded base of mp3 players

• RSS – Really Simple Syndication• Not just for audio• Uses XML

Elements of a podcast

• XML eXtensible Markup Language simultaneously

human- and machine-readable format, easily constructed

• SubscriptionNot like a print subscription, but an instruction to

check to see if new content is available and download it, if it is

WKAR – podcast implementation

• June 2005• Anger can be positive

Deconstructing NPRWe can get together next week, but we'll need Harold in on it. He's not in 'til Monday, so we can't set a date yet.For discussion:The podcasts indexed by The NPR/PRI/APM demonstration project (our page http://wkar.org/podcast/) follow a format with these elements:

Music tag/theme"This is..." program name and descriptionsponsor support messageProgram as airedthanks for listening mssgsponsor/support messagemusic tag/theme

except the GLRC podcasts do not have a sponsor message

item 1/7 is the same for all podcasts in this group, whether they are from PRI, NPR, GLRC, etc.

Automated capture

• Regular, recurring events must be automated• Shell scripts and cron (one minute granularity)• Upcut problem: takes a while to start up mp3

encoder• Solved by: starting a minute early and sleeping for 58

seconds until starting the capture would happen at exactly the correct time.

• ID3 tags• Title – Episode Title or summary of content• Artist – Producer/Host and copyright holder• Album – Title of Series or show name

Automated capture

• ID3 Tags• Just like MPS: HD Radio• Tag metadata drawn from mySQL database using

PHP script, utilizing the same data we use for our streaming file archives.

Automated packaging - mp3cat

1. audio ‘signature’

2. title announcement

3. funding credit

4. program

5. thank you for listening

6. funding credit

7. audio ‘signature’

Automated RSS file creation

• Metadata - using PHP, draw from mySQL database, and create RSS file.

• RSS file is key - provides metadata to feed readers (iTunes, Juice, et al)

Are you being served?• Podcasts are a download, usually from a web

(http) server. RSS files are XML files and can be delivered by the same server.

• 550 MHz Celeron, 192 MB RAM, 250 GB HD• LAME process only uses 37% of processor to

encode 64 - 160 kbps mp3’s• concatenation and tagging can use all of the

processor, but can play nice if needed• can saturate 100Mbps Ethernet

Content possibilities• Locally produced programs to which we hold

the copyrights (e.g. Off The Record, Quizbusters)

• Educational purposes - IVS supports classroom activities, ancillary information

What does it look like?

What does it look like?

What does it look like?

What does it look like?

More information• This presentation at:

• http://msu.edu/~beer/

More information• Useful tools -

• lame - mp3 encoder• perl - scripting language• PHP - scripting language• mp3cat - mp3 concatenator• mySQL - database

• Useful websites:• feedvalidator.com - RSS validation• id3.org - id3 tag HQ• blogs.law.harvard.edu/tech/rss - rss spec. page

Special thanks to Bill Richards, WKAR Webmaster