Oct 27, 2008

Encoding Tools

You should understand clearly by now that your podcast must be encoded in a format that is suitable for Web distribution. To do this, either you must use a standalone encoding application or export directly from your audio-editing or video-editing software. If you want to be a real podcasting hot shot, you may want to encode an enhanced podcast or offer video podcasts for various portable media players. If so, you'll probably want to invest in a multi-format encoding solution. In addition to enabling you to encode a single file into a number of different formats, they let you tweak all the encoding settings so you can get the highest possible quality encoding.

Your decision about which encoding software to use will be based on a number of factors:

  • Are you encoding audio or video podcasts (or both)?

  • If you're producing audio podcasts, do you want maximum compatibility across media players, or would you rather produce a cutting edge podcast with features that may not work on all players?

  • If you're producing video podcasts, how many formats do you want to produce?

    Podcasting purists consider podcasts to be MP3 files. But video podcasts are becoming increasingly popular, and there are serious cross-compatibility issues with video podcasts. Portable media players support different codecs, and some people may not have the required player software installed to watch your video podcast on their computer.

    We'll talk about these issues a little later in the chapter. To begin with, let's start with the simplest case. We'll assume that you're producing an audio podcast, and for maximum compatibility you're using the granddaddy of all podcast formats, the MP3 file.
  • Oct 7, 2008

    File Formats : MP3, QuickTime, Windows Media, RealMedia, Audible

    Knowing about codecs is important, because the codec determines the final quality of the podcast. However, you also have the problem of file formats. The file format dictates how the audio and video information is packaged. Some codecs can fit into a number of different file formats. The problem is that most proprietary systems such as QuickTime, Windows Media, and Real use proprietary file formats to hold the encoded audio and/or video information. File formats are highly guarded trade secrets and the main cause why files are not interoperable between players. However, the file formats also enable the proprietary systems to offer additional functionality. These are the most common file formats you'll encounter:

  • MP3: MP3 is actually a codec, not a file format. The file format is actually MPEG. (MP3 stands for MPEG II, Layer 3.) MPEG files are almost universally playable and the reason most folks use MP3 to encode and distribute their podcasts.

  • QuickTime: The QuickTime file format is the earliest multimedia file format and the basis of the MPEG 4 file format. QuickTime files also are almost universally playable, though the codecs inside may not be.

  • Windows Media: The Microsoft standard, Windows Media obviously plays back on any PC and a large number of portable media devices, but not the iPod.

  • RealMedia: RealNetworks' file format, this requires the RealPlayer. It is supported on many cell phones.

  • Audible: The Audible file format was designed specifically for audio books, and consequently supports saved playback position, chapter marks, book marks, and other desirable features. Because it has been around for quite some time, it has lots of support in proprietary players and portable media players.

  • As mentioned earlier, your choice of codec and file format depend on what audience you're trying to reach and what features you want to use. For most folks, MP3 works well for audio because it plays on virtually every computer system and portable audio player. It doesn't support book marks or chapters, but most podcasts are short enough that they don't require that functionality.

    For video, most folks are using QuickTime, again because of the near-universal support and because of the iPod, of course. However, some people are starting to experiment with other formats to see what they can do with the advanced functionalities they offer. Always offer the MP3 and QuickTime versions. If you want to play around with the advanced formats, offer them in addition to your standard podcast versions.