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Podcasting


There are differences between podcasts and web delivery of audio and video files, here is an example of both: Sample.


Technically, a podcast is only an RSS feed with enclosures, these can be audio, video or PDF files. Here is a link to a podcasting workflow chart.




Link to Apple podcasting specs


From archives:

What is Podcasting?

Podcasting is a method of publishing programs via the Internet, allowing users to subscribe to a collection of audio and video files, called a feed or channel. Any files added to the channel are automatically downloaded to the user's personal computer, using podcast aggregator software like iTunes. These files, or episodes, can then be listened to later, at the user's convenience.

The goal of podcasts is to allow users to keep up to date with a range of different audio and video sources. The client software, like iTunes, maintains a list of content sources and periodically and automatically checks them for new file releases.

Another benefit of podcasting is that listeners can sync the content of iTunes, or their podcast client, to their iPod or other portable media player, and take the files with them to listen to, whenever they want.

Technically, a podcast is only an RSS feed with enclosures, these can be audio, video or PDF files. Here is a link to a podcasting workflow chart.

There are differences between podcasts and web delivery of audio and video files, here is an example of both: Sample.

A good source of educational podcasts is Open Culture, there are many links in the "Podcast Library" sidebar, and in the blog entries.

How to subscribe to a podcast:

  1. A direct link in a web page automatically opens up iTunes, and allows you to subscribe. This uses the itpc URL link.
  2. In iTunes, use Advanced>Subscribe to Podcast. Each podcast has a unique URL (web address) For example, subscribe to http://video.conncoll.edu/podcast/podcast.xml, in iTunes
  3. In iTunes U
  4. in the iTunes Store, under Podcasts

Podcast clients

A podcast requires an RSS file, written in the xml language, that can be subscribed to with a podcast aggregator, and usually includes more than one episode or item. The RSS specs allows an item to have an "enclosure", which is a way of attaching multimedia content to RSS feeds. So, an RSS file with enclosures is called a podcast. The enclosures are not really embedded, they are just URL pointers to external files on a web server.

Depending on the format, the same media file can be used both in a web page, as a "click to hear", and in an associated podcast.

Media formats that can be used in podcasts are:

audio: mp3, mpeg4 (extensions mp4, m4v, m4a), QuickTime (mov)
video: mpeg4 (extensions mp4, m4v), QuickTime (mov)
So, you can put a Flash file it in a web page, but not yet in a podcast.

Podcast clients are also called podcast aggregators. The aggregator provides a consolidated view of the content in a single browser display or desktop application. Such applications are also referred to as RSS readers, feed readers, feed aggregators, news readers or search aggregators. Aggregators with podcasting capabilites can automatically download media files, such as MP3 recordings. In some cases, these can be automatically loaded onto portable media players (like iPods) when they are connected to a computer.

Any RSS reader can subscribe to and read the RSS file itself. However, not all readers can detect, or know what to do with, the enclosures.

Some aggregators allow you to view and hear the episodes in a podcast, but do not automatically download them to your computer.

These are the basic categories:

Browsers- Modern web browsers can decode the xml in the RSS feed, and show the enclosures. Need to test subscriptions. They do not automatically download the episode, nor organize them in a podcast after download.

Web-Based Aggregators

  1. Bloglines-shows mp3 in player, not mov, link to "enclosure", no download button (save as?)
  2. Google Reader-shows mp3 in a player, but not mov, showes link to mov, no download button (save as?) (Mac-S,F)
  3. Newsgator

Customizable Web-Based Portals and Home Pages

  1. My Yahoo-shows links to mp3 and mov files (Mac, S, F)
  2. iGoogle-does not show enclosures (Mac-Safari 2 and Firefox 2)
  3. Netvibes-does not show mov, player for mp3, download button for mp3 (Mac-S,F)
  4. PageFlakes-the built-in RSS reader does not show enclosures. But the main page does, with buttons to play in PageFlakes, or in external page. mov does not play in PageFlakes, mp3 does.

Software Aggregators- iTunes, Juice. These are not web-based, but applications on your computer.

A podcast client should:

  1. Allow you to subscribe to the podcast RSS feed.
  2. Automatically check for new episodes (items), and flag them, at user-defined intervals.
  3. Support as many podcasting file types as possible, regarding detecting them and playback ability
    1. audio: mp3, mpeg4 (extensions mp4, m4v, m4a), QuickTime (mov)
    2. video: mpeg4 (extensions mp4, m4v), QuickTime (mov)
  1. Download the new files in the background, so you can listen/view them later.
  2. Allows you to manage your podcasts. Keeps all the files in one subheading. Delete certain files.

Additional features found in iTunes

  1. Allows you to see and directly subscribe to many podcasts in the iTunes Store
  2. Supports PDF files in podcasts

Creating Simple Audio Podcasts

There are three steps to creating a podcast: 1) Recording, 2) Compressing, and 3) Uploading. These steps, detailed below, use a microphone connected directly to a computer. The procedures provide quality adequate for many purposes. If you need better quality, you have to use a better mic, or a different recording device, and a quiet location. Please see us for advice.


1. Recording

There are two main approaches to recording: using QuickTime Player Pro, or using Audacity.

Record using QuickTime Player Pro

The following instructions are for recording one voice, on a PC or Mac. You need a Plantronics Headset, which includes a microphone, and QuickTime 7 Pro on a computer. QT 7 Pro is available in the Advanced Technology Lab, the Digital Curriculum Center, the Neff Lab, and the PC Electronic Classroom. Plantronics headsets can be checked out at the Shain Circulation Desk or at the DCC. QT Player Pro is also available from Apple for $30.

With a PC (Windows)

  1. Connect the headset to the USB connection in the front of the PC
  2. The PC should automatically recognize the headset. Wait until all the dialog boxes in the lower right go away.
  3. Push the Mute button on the headset control so the red light goes off, this unmutes the mic. Note the volume control for the earphones. For now, leave it alone.
  4. Open QuickTime Player Pro, go to Edit>Preferences>Player Preferences>Audio Recording.
  5. Click on Microphone: "Choose". This will open the Sounds Control Panel.
  6. In the Audio tab, select the Plantronics Headset in both Sound playback and Sound recording as the default device.
  7. Click on the Sound Recording Volume button. Drag the slider all the way to the top. Close this window.
  8. In the Voice tab, select the Plantronics Headset in both Voice playback and Voice recording as the default device. The other default settings should be fine. The "Test hardware" button may help resolve technical problems. Close the control panel.
  9. In QT Preferences select Format: Uncompressed Audio (.mov). Select Apply. Close the control panel with the OK button.
  10. In QuickTime Player, go to File>New Audio Recording. Place the mic about 1” away from your mouth, off to one side and not directly in front of your mouth. When you speak, the level meter should register about half-way to two-thirds of the way. If it is "in the red" a lot, go back to the Sound Recording Volume slider, and drag it down a bit.
  11. Click the red recording button to start recording. Click it again to stop.
  12. The file will automatically be named. To rename it, close the file, and rename it on the desktop. Do not rename open files.
  13. For very simple editing in QT Player Pro, you can select portions of the audio, with the in/out selectors below the timeline, and use the Edit>Cut, Copy and Paste commands.
  14. If you disconnect the Plantronics mic while QT Player is open, the player may crash. Quit the player before you disconnect the mic.
  15. For the next step, go to "Compressing the Audio File", below.

With a Mac (OSX)

  1. Connect the headset to the USB connection in the front of the Mac.
  2. Push the Mute button on the headset control so the red light goes off, this unmutes the mic. Note the volume control for the earphones. For now, leave it alone.
  3. In the Apple Menu in the upper left, select System Preferences. Select the Sound control panel.
  4. In the Output tab, select the Plantronics Headset. In the Input tab, select the Plantronics Headset, and slide the Input Volume control all the way to the right.
  5. Open QuickTime Player Pro, go to QuickTime Player>Preferences.
  6. In the Recording tab, select the Plantronics Headset in Microphone.
  7. In Quality, select Device Native. Save files to desktop. Close the control panel.
  8. In QuickTime Player, go to File>New Audio Recording. Place the mic about 1” away from your mouth, off to one side and not directly in front of your mouth. When you speak, the level meter should register about half-way to two-thirds of the way. If it is "in the red" a lot, go back to the Sound control panel, and lower the Input volume a bit.
  9. Click the red recording button to start recording. Click it again to stop.
  10. The file will automatically be named. To rename it, close the file, and rename it on the desktop. Do not rename open files.
  11. For very simple editing in QT Player Pro, you can select portions of the audio, with the in/out selectors below the timeline, and use the Edit>Cut, Copy and Paste commands.
  12. When you are done recording, disconnect the Plantronics headset, and restore the Sound control panel to Output>Line Out.
  13. For the next step, go to "Compressing the Audio File", below.


Record Using Audacity

If you need more editing power than QT Player Pro can provide, Audacity is a good choice for simple editing. It is a free PC/Mac/Linux audio recorder and editor. It is not yet installed on any IS computers, but can be installed on your own computer. It is available for download here. The Audacity windows look the same on the PC and the Mac.

Preparing to record on a PC

  1. Connect the headset to the USB connection in the front of the PC
  2. The PC should automatically recognize the headset. Wait until all the dialog boxes in the lower right go away.
  3. Push the Mute button on the headset control so the red light goes off, this unmutes the mic. Note the volume control for the earphones. For now, leave it alone.
  4. Right-click the speaker icon in the lower right of the screen, and select "Adjust Audio Properties". This control can also be found in Control Panels>Sounds and Audio Devices.
  5. In the Audio tab, select the Plantronics Headset in both Sound playback and Sound recording as the default device.
  6. Click on the Sound Recording Volume button. Drag the slider all the way to the top. Close this window.
  7. In the Voice tab, select the Plantronics Headset in both Voice playback and Voice recording as the default device. The other default settings should be fine. The "Test hardware" button may help resolve technical problems.
  8. Open Audacity. In Edit>Preferences>Audio I/O, select Plantronics Headset for Playback and Recording Device. Select Channels: 1 (Mono). Your PC screen should now look like this:



Preparing to record on a Mac

  1. Connect the headset to the USB connection in the front of the Mac
  2. Push the Mute button on the headset control so the red light goes off, this unmutes the mic. Note the volume control for the earphones. For now, leave it alone.
  3. In the Apple Menu in the upper left, select System Preferences. Select the Sound control panel.
  4. In the Output tab, select the Plantronics Headset. In the Input tab, select the Plantronics Headset, and slide the Input Volume control all the way to the right.
  5. Open Audacity. In Audacity>Preferences, Audio I/O, select Plantronics Headset for Playback and Recording Device. Select Channels: 1 (Mono). Your Mac screen should now look like this:


Recording in Audacity

1. Keep the mic element about an inch from your mouth, and off to one side.

2. Above the Mic icon in the upper right is the audio input level meter. In the drop-down arrow, select "Monitor Input". Start speaking, the level meter should be close to the Zero point, without tapping it too often.

3. To start recording, push the red button. A new audio track will be automatically created. When the cursor starts to move, start speaking.

4. You will see the waveform of your recording. Ideally, it should be between half and full height on the 0 to 1 vertical volume scale on the left.

5. Here is an example of adequate recording levels:


6. To pause the recording, press the Pause (blue vertical bars) button. To start recording again, on the same track, press the Pause button again. To end the recording on this track, press the Stop button (yellow square).

7. If you stop a recording, and start a new one, a new audio track will be automatically created under the first one. Audio tracks can be deleted by clicking on the close box (X) in each track's upper left.

8. The Audacity Microphone volume control works on the Mac, but not on the PC. You must control the recording volume on the PC through the Control Panel.

Basic Editing in Audacity

Audacity is a powerful audio editor, extensive documentation can be found here.

The Basic Tools are:



You can drag back and forth in the timeline using the windowing tools. Basic Audacity editing:

1. Select a region of silence before and after the recording with the Selection Tool. Delete it with the Delete key.

2. Select a pause or audio you don't want in the middle of the recording with the Selection Tool. Delete it.

3. If you have two recordings on two different audio tracks, copy and paste one selection from another. Then delete the track that is not needed. When you are done, you should have only one audio track.

4. If the audio track volume is too low, make a selection of the low portions and go to Effect>Amplify. Set the New Peak Amplitude at -2 dB.

To export your final file, go to File>Export as wav. Give your file a short name, unix friendly (only letters, numbers, underlines, dashes), with the wav extension. Make sure you know where you are saving the file!

For the next step, go to "Compressing the Audio File", below. This compesses the file using iTunes. Audacity can also compress directly to mp3 using the LAME library. This needs to be download from the Audacity web site, and installed separately.


2. Compressing

Compressing the Audio File

Using the above procedures, the audio is recorded as uncompressed. It needs to be reduced in size, or compressed, for delivery. It is possible to record audio immediately in a compressed format, but later editing is harder, its is also harder to control the amount of final compression. We have special software to record compressed audio directly if you need to do so. Audio that is already compressed should not be recompressed again, there is a potential large loss of quality.

Deciding on audio compression: mp3 or mp4?

When compressing, you need to decide whether to compress to mp3 or mp4 (also called AAC). mp3 is available on more devices, mp4 will generally sound better at the same file size and data rate. mp3 will play on all portable players, including iPods. mp4 plays on iPods, but not all portable players. mp4 files can be used in enhanced podcasts, described later, mp3 files cannot. mp3 and mp4 files can be used in the same podcast. Either format will play fine on a computer, both formats are supported at Connecticut College.

There are many ways to compress audio files, the directions below use the iTunes "compression engine".

How to compress to mp4 (AAC)

  1. Open iTunes, select Music Library on the left.
  2. Go to iTunes Preferences (PC: Edit>Preferences, Mac: iTunes>Preferences)
  3. Click on Advanced>Importing
  4. Select Import Using: AAC Encoder, Setting: Spoken Podcast, Click OK.
  5. Drag your uncompressed audio file into the iTunes song list, or go to File>Add to Library, and add the file. If you sort by Date Added, it will be at the top. You can change the column views in iTunes>View>View Options. You can drag columns back and forth.
  6. Select your file, and go to Advanced>Convert Selection to AAC. The new mp4 file will now be at the top. Drag the file from iTunes to your desktop. It will have the m4a extension.
  7. Reset your iTunes default Importing settings (AAC, High Quality).

How to compress to mp3

  1. Open iTunes, select Music Library on the left.
  2. Go to iTunes Preferences (PC: Edit>Preferences, Mac: iTunes>Preferences)
  3. Click on Advanced>Importing
  4. Select Import Using: MP3 Encoder, Setting: Custom, Stereo Bit Rate 64 kpbs, Sample Rate: 32 kHz, Channels: Mono, check off any boxes below. Click OK.
  5. Drag your uncompressed audio file into the iTunes song list, or go to File>Add to Library, and add the file. If you sort by Date Added, it will be at the top. You can change the column views in iTunes>View>View Options. You can drag columns back and forth.
  6. Select your file, and go to Advanced>Convert Selection to MP3. The new mp3 file will now be at the top. Drag the file from iTunes to your desktop. It will have the mp3 extension.
  7. Reset your iTunes default Importing settings (AAC, High Quality).


3. Uploading

Uploading the recording to a podcast

If you already have a podcast, follow the directions for Uploading to your Podcast.

If you do not have a podcast, and you need one for instructional support, please contact Frank Fulchiero to set one up.



Using an iPod for Recording

You may find it easier to use an iPod with mic, which we can lend you, for simple recordings or field recordings. The directions are here. These include instructions for compressing the audio to mp4.

Notes

  1. We have wireless lavalier mics available, these allow you to move around while speaking and can record to either a computer or an iPod.
  2. While presenting on your computer, you can record both your narration and the computer screen, using additonal software. This is called a Screencast.
  3. These portable recording devices are available to borrow: iPod with microphone, analog cassette recorder, Digital Audio Tape recorder, and MiniDisc. We also have a telephone interface to allow recording both sides of a telephone conversation.
  4. Please contact us for any assistance, or specialized applications.

Pedagogical Information and Resources

Educause May 2007 overview

University of Wisconsin, some good podcasting production information.

Informative earlier article in American Federation of Teachers by Jean-Claude Bradley, who co-ordinates new technologies at the College of Arts and Sciences at Drexel University. A Quote:

"The arrival of this technology is forcing some teachers to re-evaluate their role as educators. If the recorded lecture is available online, why go to class? This concern is voiced in much of the dialogue taking place online over this topic (see, for example this article).

One approach to deal with attendance is to only give partial material so that the students still will have to come to class for the full benefit. But if an archived lecture is just as effective as a live one in transmitting the basic subject matter, that can be an opportunity to shift the role of the teacher to a higher, more interactive level. Lectures can be assigned and class time can be spent integrating knowledge through conversation and creative assignments that deal with real world applications of the subject matter. We have only begun to see what this technology will make possible for the future of education."

Here are some of Jean-Claude's more recent general observations

Often, podcasts are combined with weblogs (blogs), wikis, screencasts, and other new technologies for the purpose of teaching and learning.

Connecticut College Podcasts

We currently host 16 podcasts:

Featured in the iTunes Store

Instructional Technology Team Podcast
Bioluminescence - Marc Zimmer Podcast
(note, the above two are direct links to the iTunes Store. If they do not work, follow the directions below for adding the podcast manually to iTunes)


Web Links

David Dorfman's "underground"
Healthy Lifestyle Initiative (2 podcasts)


Manual Subscriptions - In iTunes, go to Advanced>Subscribe to Podcast, and enter these URLs:

http://video.conncoll.edu/d/at/podcast.xml for the Arts and Technology Symposium
http://video.conncoll.edu/podcast/podcast.xml for the Instructional Technology Team podcast. We need to add the second episode to the iTunes version.
http://video.conncoll.edu/f/mzim/podcast.xml for Mark Zimmer's podcast
(Note, the direct links may also work in certain browsers, like Safari on the Mac. In IE7 on the PC, the media will play, but only after it has completely downloaded.)


Our academic podcast server admin page is at http://video.conncoll.edu/weblog/

Password Protected Podcasts:

Two podcasts for Michael Reder, FYS105

Podcast for Robert Gay, SOC414

Three podcast for Hisae Kobayashi , Japanese 202, Japanese 102, Japanese 201

Podcast for David Kyuman Kim, Religion 401

Podcast for Tek-wah King and Yu Liu, Chinese 101

Other institutions' podcasting web sites

Interesting Educational Podcasts

  • Open Culture, Links to hundreds of educational podcasts. A great resource!

Video Podcasts

The specifications for video podcasts have recently changed.

The new ones are listed here

To see a sample of excellent podcasts that also look great with Apple TV, check out the

Apple TV Podcast Showcase

Washington Post Video Podcasts, be sure to check out the HDTV one!

Apple TV is a device that wirelessly receives iTunes content, and displays it on a televison.

Podcast Specifications and Metadata

If you want to post your podcast to the iTunes store, you have to follow these specifications:

http://www.apple.com/itunes/store/podcaststechspecs.html

The above page includes a link for submitting podcasts to the iTunes store.

Our academic podcast server does not, at this time, generate tags for the iTunes store. To do this, you either have to hand-code the RSS file, or use software like FeedForAll to automatically generate the code.

For more information on using metadata in iTunes and in podcasts, go to our iTunes Metadata page (link to be entered)

id3 Tags in iTunes (this is an older article)

International and Foreign Language Podcasts and Podcasting

Marisa, on April 7 '07, pointed out a nice new link on Foreign Language Podcasting

Techniques and Tips

Software, Tools and Services

  • The Levelator (PC/Mac) levels out volume changes in simple voice recordings
  • Ubercaster (Mac), Podcast recorder, editor and producer
  • Loudblog is an easy-to-use Content Management System (CMS) for publishing media content on the web.
  • Podcaster creates podcasts with iTune Store tags, and enhanced podcasts.
  • FeedForAll (PC/Mac), one of the more mature and better commercial tools
  • Feeder (Mac), a tool for OSX to create and publish RSS and podcast feeds.
  • ProfCast (Mac), a versatile, powerful, yet very simple to use tool for recording presentations including PowerPoint and/or Keynote slides for creating enhanced podcasts.
  • VODcaster (PC/Mac), A Tool for Publishing Audio and Video Podcasts
  • HappyFish (PC) RSS and podcast client, can download enclosures
  • Juice (PC/Mac) podcast client

Conferences

  • PodcasterCon 2006 and 2007, with wiki and blog. They used a wiki to write up pre-conference details, ongoing conference content, and post-conference information.

"Dave Warlick promised an "un-conference" and that is exactly what he delivered during his afternoon session on podcasting in education.

He first briefly demonstrated a few examples of educational podcasts. Then he asked who had audio recording capability and divided up the "audience" into 6 groups that each recorded their conversation. Each group was tasked to generate 3 answers to questions relating to educational podcasting. My group talked about the issues related to ownership of content.

Dave then asked someone to take notes into a wiki as he and Steve Dembo got every group's ideas over a microphone. The rest of the 2 hour session was spent collecting additional information from anyone on any part of the topic. Here is the resulting wiki page"

Some PodcasterCon Video

Articles and General Reference

  • Podcasting News, If you are going to check only one site, this is one of the most comprehensive.

Podcast Search Sites

Receiving Podcasts without iTunes

For some reason, some folks may not want to use iTunes as a client. Here is other computer-based software that may work:

Juice may work, need to test it.

NOTE: We need to investigate what portable devices, besides iPods, can sync to podcasts.

Advanced

Extending RSS 2.0 with Namespaces

Putting more information in your RSS feeds

TSI 2007 Presentation and Tutorial

Click the above title to see this. Takes about 1 hr and 15 min to implement.

Podcast Server

We now have a Podcast Server, at http://video.conncoll.edu/weblog/

If you would like to create a podcast for the purpose of instructional support, please contact Frank Fulchiero for an account

Admin Configuration

To start a podcast:

  1. In video.conncoll.edu, Workgroup Server, create a new faculty account, put them in "faculty" group.
  2. Create a new student account, do not put in any groups
  3. Log into podcast server, create a new podcast by entering the faculty account name
  4. Upload a test file
  5. In Settings, change name of podcast, description, and add as readers the faculty and the student accounts.
  6. In Tomcat/blojsom_root/webapps/ROOT/WEB-INF/blogname/blog.properties, change
    1. blog.comments.enabled=false
    2. blog.trackbacks.enabled=false
    3. blog.entries.displayed=, change to desired, default is 15

To delete a podcast:

  1. take out the user file in Tomcat/blojsom-root/webapps/ROOT/WEB-INF/
  2. take out the user file in Tomcat/blojsom-root/webapps/ROOT/blojsom_resources/meta/
  3. Overall podcast properties in WEB-INF/default/blog.properties, take out user name

To change appearance of weblog go to Library/Tomcat/blojsom_root/webapps/ROOT/WEB-INF/templates/html.vm

Change with a text editor like TextWrangler. Make a backup before changing anything. Before running software updates, copy the html.vm file to the desktop, it may be overwritten.

Use <!-- xxxxx --> to comment out code, instead of deleting it

Permissions: tomcat/blojsome-root/webapps/root/blojsom-resources/images owner: appserver rw, appserveradmin rw, others none

Archives

Podcasting-TSI08  (Also see above instructions)

Our own Simple Podcasting Primer, older but has good RSS code information

Podcasting Equipment and Studios (July 2006, needs to be updated)

RSS Information-This section needs to be updated.

Mac RSS readers

Desktop PC, Mac and web-based RSS readers

State of the Aggregator

RSS feed manager

secure RSS syndication

RSS for Educators guide (pdf)


Podcasting Equipment and Studios