I’ve been posting at least one and often two podcasts per week as part of my day job as Editor MobileAppsToday.com and MobileDevicesToday.com. The vast majority of these podcasts are recorded Skype conversations saved as AIFF files, volume leveled using the freeware Levelator, and the processed using the Open Source Audacity audio editor to add the intro music and a commercial before mixing it down to an MP3 file.
This all worked reasonably well except for one minor and annoying issue. The podcast length reported in the iTunes feed was always incorrect. iTunes always reported the podcast being about twice as long as it actually was.
I ran into another problem with my most recent podcast (#16 with Frank McPherson). My podcasting host service limits the size of MP3 files to 30MB. This seems pretty reasonable. However, Frank and I found a lot to talk about in podcast 16 and it went a bit over an hour long. When I processed the first MP3 file, it was over 30MB large. Since I didn’t want to edit the discussion to a shorter period, I took a look at Audacity MP3 saving options and noted that I had been saving my files using the Stereo option. I reasoned that using the Joint Stereo option might reduce the complexity of the audio file and let the MP3 encoder reduce the file size a bit more.
This, as it turns out, was correct. My file dropped from over 30MB to just a bit over 20MB. The added bonus was that changing this audio option also fixed the podcast time length problem over on iTunes. So, starting with podcasts 15 (W3c’s Deborah Dahl) and 16 (Frank McPherson), my podcast lengths are reported correctly in iTunes.