Step-by-Step Encoding Examples | Podcast

Now it's time to actually encode some files. This section demonstrates audio and video encoding using stand-alone encoders, editing platforms, and even iTunes. If your editing application isn't demonstrated, don't worry: It probably works much the same way. Let's start with iTunes, which really isn't an encoder, but it can do the job.

Tip You should always archive the high-quality version of your file so that you can re-edit or re-encode it later.

Encoding MP3 audio using iTunes
iTunes automatically encodes all imported audio. When you insert a CD and iTunes offers to import it, the audio bits are pulled straight off the CD and encoded into whatever format has been specified. The default setting is to encode using AAC. However, iTunes will also convert music in MP3 if you prefer, and will convert any file into an MP3 file. All you have to do is import the file into iTunes, and then convert it to MP3.

Setting MP3 encoding defaults
To use iTunes as an MP3 encoder, you have to set the default encoding to MP3. Follow these steps to set iTunes to import using the MP3 codec:

1. Open iTunes, and open the Preferences window by choosing Preferences from the iTunes menu (the Edit menu on a PC). You also can open this window using the keyboard shortcut Command+, (Ctrl+, on a PC).

2. Click the Advanced icon/tab, and select the Importing tab.

3. Select MP3 encoder from the Import Using drop-down menu.

4. Select your bit rate from the Setting menu. By default, the lowest setting offered is 128 kbps stereo. For most podcasts, this is a perfectly fine setting. If, however, you want to economize on your bit rate, you can adjust the settings by selecting Custom from the Setting drop-down menu.

5. Select a bit rate from the Stereo Bit Rate drop-down menu.

6. You can select a sample rate or leave this set to Auto. If your podcast ends up sounding a little crunchy or distorted, you can try lowering the sample rate to get better fidelity.

7. If you want a mono podcast, select Mono from the Channels drop-down menu.

Note If you select Mono encoding, the bit rate will be half of what you specified in the Stereo Bit Rate drop-down menu.

8. Click OK to close the Custom Settings menu, and then click OK to close the Preferences window. iTunes will now import files using the MP3 settings specified.

Importing and Encoding
To encode using iTunes, you must first import the file, and then convert the imported file. Importing couldn't be simpler:

1. From the File menu, choose Import.

2. Browse to find the file you want to encode, and click Choose (Open on PCs). The file is imported and is listed in your music library.

3. Find the file in your music library. Click it to select it, and then from the Advanced menu, choose Convert to MP3.

That's all there is to it! iTunes encodes it using the settings specified on the Importing tab of the Advanced menu. The iTunes music folder is easy enough to find, but if you want to encode to a specific location, you can change this setting in the General tab of the Advanced settings window.

Caution Be careful when you change your iTunes music folder; otherwise, you'll end up with your music library in two different folders. It's probably a good idea to change the music folder back to the default after you've finished your encoding.

MP3 Encoding Tools

If you're producing an audio podcast, you're probably best producing it in the MP3 format. Although it isn't the best audio codec available, it is by far the most compatible and plays on virtually any computer or portable media device. It may not have all the bells and whistles of other formats, but your audience is far less likely to have technical issues, which means you'll get fewer negative comments on your blog.

Virtually any editing platform you're working on should have built-in MP3 encoding capabilities, but on the off chance that it doesn't, a number of standalone MP3 encoding applications can get the job done; one such application is shown in Figure 1.

iTunes: iTunes isn't really an encoding application, but it converts audio files to mp3 on import if you choose to do so in your preferences.

LAME-based encoders: Despite the ironic origin of the name (Lame Ain't an MP3 Encoder), LAME is an open source MP3 encoding library that is used in almost all free MP3 encoding applications. There are probably hundreds of these available; google "MP3 encoder" and see for yourself.


Figure 1: WinLAME is one of many free MP3 encoders available.

Subscribing to Your First Podcast in iTunes

iTunes' interface is basically the same in Macintosh and Windows, though here we're going to walk through the subscription process in the Mac version. Again, let's assume that you've got an RSS reader that typically handles your RSS subscriptions, so we've copied the URL of the XML file used by CNET's Buzz Out Loud podcast RSS feed. Now, open iTunes and click the Advanced menu, where the second option is Subscribe to Podcast.

1 - Select the Subscribe to Podcast… option in the Advanced menu, which opens a dialog box where you paste the URL of the podcast RSS feed of the program. When you click OK in this dialog box, iTunes queries the server and retrieves a list of available shows. It downloads only the last podcast immediately, leaving the rest for your review and, if you like, downloading. iTunes also continues to check the server on a regular schedule for new shows, downloading new programs as they are released.

2 - iTunes doesn't display lots of information about each show, so you can Ctrl+click (with a one-button mouse) or right-click (with a three-button mouse) the title and select Show Description to read show notes, which include guest lists, topics discussed, and songs played on the program.

3 - If you select Get Info, you get a much more complete view of the metadata for the podcast and individual shows, including the show logo, encoding format, bit rate, sample rate, and so forth. Click the Info pane in the Get Info dialog box to see the show notes.

4 - To play a podcast, double-click the title in the iTunes library.