Creating a course audio lecturecast (podcast) with Podcast Generator

Podcast Generator is an open source content management solution specifically customized for podcasting. Since it's open source, it's free but you need to have access to a webserver supporting PHP scripts to use it. It permits users to upload audio files directly using a web browser, and share them as podcasts within a created RSS feed / web feed to which others can subscribe. I've been wanting to give it a try for a couple of years, since I learned about it, and this semester's "Computers in the Classroom" course I'm teaching at the University of North Texas has provided a great opportunity to use it. The website and lecturecast channel I've created for my students this semester is available on cicpodcasts.speedofcreativity.org. In this post, I'll briefly review the steps I took to create this site and start sharing (mostly) unedited audio recordings from our classes this term.

Last semester I taught "Technology 4 Teachers" at the University of Central Oklahoma, and was able to create video lecturecasts using Ustream.tv, Blip.tv, and other tools. See my post from January 2010, "Lecturecasting on a Shoestring with a Macbook, Ustream, CamTwist, MPEG Streamclip and Blip.tv" for more about that process. This semester, it's not practical for me to video record my own classes, but it's very easy to use a battery operated digital audio recorder for this purpose. I am using my (now discontinued) Sony UX-71 recorder for these recordings, but other models for $50 US and under can work too.

My audio recorder is set to record at a relatively high bit rate of 128 kbps. I could reduce this, but I'd rather not take a chance of making a recording at a low quality setting so I have kept it at that default. It's NOT good to publish mp3 audio online for a lecturecast with that high level of quality, however, because the file size is too big. This would make download times longer for students, and also (if this is a concern) consume more of your monthly bandwidth quota with your web host. My 1.5 hour class recording is about 29 MB in size, uncompressed as it is recorded by my device.

There are several ways to compress an audio file and reduce its file size. iTunes can do this, and you can add podcast show art as well as other ID3 tag information if you use it. Audacity can compress files too, as can QuickTime Pro. I'm using the free, cross-platform program Switch to make these audio compressions, however, because it's free, fast and easy. I've found it's possible to reduce the bit rate to 16 kbps with Switch and still have passable audio quality.

This REALLY cuts down the file size, from almost 30 MB to just under 10 MB.

The speed of the conversion will depend not only on your original file size and settings, but also the speed of your computer. My three year old Macbook Pro does this conversion in less than two minutes.

After you have compressed mp3 files ready to upload, you need a website to use to publish your podcasts. I considered using iPadio, and actually uploaded our first class lecturecast to drop.io, but when I couldn't remember my drop.io guest password today (yes, I was silly and didn't write it down somewhere when I created it) I decided to try a custom website using Podcast Generator.

My current web host (SiteGround) provides CPanel access to create new sub-domains. This is what I wanted to use for my site, so instead of something like "www.speedofcreativity.org/cicpodcasts" for the address, it would be "cicpodcasts.speedofcreativity.org". Functionally this doesn't make a difference, I just think sub-domains look cool and more professional. They may be easier for others to remember too. See my video podcast from September 2008, "Setting up a SubDomain with cPanel" if you'd like more guidance on this process. Other web hosts (like Bluehost) should have a similar procedure if they support CPanel.

After I had the subdomain created, I expected I'd need to create a new MySQL database and user account to configure Podcast Generator. I was pleasantly surprised to learn that was NOT the case! After uploading all the unzipped Podcast Generator files to my webhost using FTP (I use Cyberduck - free) I pointed my Chrome browser to the subdomain's web address. Podcast generator displayed a wizard which took me through five setup pages, and I was done! This was even easier to do than setup a custom WordPress installation!

Logged in as the administrator, with the login credentials I created with the setup wizard, I'm able to directly upload and tag new podcast episodes. I love how Podcast Generator includes a direct link in the right sidebar to subscribe to the podcast with iTunes. I'm not sure if many of my students will find these lecturecasts helpful, but we did have three absences on Wednesday so I'm guessing they could help.

I first learned about Podcast Generator a couple of years ago, when I started collecting articles for my dissertation on "coursecasting." It's fantastic open source web tools like Podcast Generator are available. MANY thanks to the developer team, led by Alberto Betella!

I hope it will become more common for college courses to be lecturecasted, at least for student use. As an instructor, it helps me to know my students who miss a class or want to review something we discussed in class have this as an available resource. It takes very little time to post a recorded audio file after class, especially once the Podcast Generator site is created. I realize many faculty would be intimidated by the technical requirements of doing this, but technical support staff at universities can certainly help out. The transparency afforded by this kind of public lecturecasting may be more intimidating to some than the process itself, however. As an advocate for OER, however, I think we should embrace the potential opportunities here.

The only disadvantage of the lecturecasting process I've described here, which I can readily identify at this point, is Switch doesn't allow for any editing of meta data. I think that may be why my two lecturecasts have an automatically generated label of "2-9-2010" on their entries. I'm not sure.

A final note: When creating podcasts, take care to avoid the "chipmunk effect" which can happen if you choose a "sample rate" for your export settings that is NOT compatible with the Flash format. See my post, "Avoiding the Chipmunk Effect in Podcasts" for more on that topic. See my October 2009 post, "How I create and publish podcasts" for more about my "normal" processes for creating and publishing podcasts.

The method I've described here, to use "no-edit" recordings of class lectures and Podcast Generator, is MUCH easier and faster. If you have suggestions or alternatives to the methods outlined here or on those other posts, I'd love to hear them! I'd also like to know of other college instructors who are publishing their own lecturecasts, and institutions which are publishing lecturecasts openly for public as well as student access. Expensive, commercial coursecasting solutions are available, and they CAN streamline this process in some cases. I think the functionality provided for FREE by Podcast Generator sets a high bar for function and usability, however, which I'd recommend using as a benchmark if you're in the market for a commercial solution.

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