Jan 3, 2009

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.

1 comment:

Unknown said...

Hi,

Just would like to share an article on audio encoding optimization for podcasting. No need to think what bit rate to choose the batch file will automatically encode your podcast with the best bit rate to preserve the best quality and smallest file size. The approach was tested on MP3, Nero AAC and OGG.

This paper will give you understanding on how one can achieve better compression ratio by bit rate optimization. The key point is that our approach describes a fully automated manner of choosing the bit rate that will preserve the audio quality you define. Read this paper through and find out how to save on size when encoding your podcasts, save on bandwidth when transmitting your audio streams in the network, make more audio tracks fit your memory stick when grabbed from a CD, or store more audio books on your mobile device. This paper will tell you how to save up to 50% on audio file size and up to 50% on the bit rate you encode your audio with still having a descent sound quality.

Read full text of how to encode audio with lowest bit rate at highest quality in this blog post: http://blog.sevana.fi/optimize-bitrate-and-size-preserving-high-audio-quality-in-tracks-podcasts-tunes-with-aqua-wideband/