If you've been following along, you've seen several posts on podcasting right here on UTM. These three posts (1, 2, and 3) all came up at the end of January/beginning of February, and since then we've been working on Audio Hijack Pro 2.5, which came out last week.

This new version features some important features to help users creating podcasts, so I thought I'd go in to some depth on the two major new features useful to podcasters (and others): the Application Mixer plugin and the Silence Input audio device.

Application Mixer
The Application Mixer plugin simplified: Audio Hijack-in-a-plugin inside Audio Hijack Pro (or Nicecast). AppMixer pulls audio from the specified source and mixes it in to the hijacked audio stream. The plugin can be found in the Effects tab, as a 4FX plugin. Add it to your Effects patch, and you'll see this:

The Application area allows you to set the source from which the plugin will pull audio. The Crossfade area adjusts the level of audio being piped in (as you can see, it defaults to 50/50). The two shiny arrow buttons will product a nice auto-fade, so if you click the Source button, the slider will gradually fade out the Application audio. Finally, the Hijack button adjusts whether audio is pulled from the Application at all.

Using AppMixer is simple, just set a source and click Hijack. Any audio from that application will then be mixed into the main session hijacking. For example, if you're recording audio from your microphone, you can mix audio from iTunes into the stream. Or you can use it to log both halves of a Skype or iChat conversation, as described in the Recording Voice Chat Audio Hijack Pro's manual. There are a lot of great uses for AppMixer.

In terms of podcast creation, there are three major uses we've seen already. Number 1, AppMixer can be used to add a call-in segment to a podcast, with listeners "calling in" over Skype or iChat (see the "Recording Voice Chat" page of AH Pro's manual for more info). Number 2, you can mix music in to your podcasts. Talk for a section and record your microphone's input, then fade over to Application in AppMixer, and play a hit new single in iTunes. Number 3, AppMixer makes it easy to drop in sound effects, by hijacking an app like QuickTime Player. All this adds up to much better podcasts with much less work.

Silence Input
Also new in Audio Hijack Pro 2.5 is the Silence Input Audio Device. This can be found in the Input tab of a session, when the session is set to Audio Device, as seen below. You might also note that we added a Silence Output, which can be helpful when pulling audio from Skype, among other instances.

At first, Silence Input might not seem to make much sense. Why would you want to record silence? When coupled with the AppMixer plugin from above, Silence Input starts to make more sense. In the above examples, a microphone was the input source. But if you want to make a more complicated setup, the Silence Input can be very helpful.

Such a setup would start with the Input tab set to Audio Device, and the Input set as Silence Input. This creates a silenc audio stream, upon which other audio can be overlaid. All audio in such a setup will come from DSP effects in the Effects tab. VoiceOver can be used for microphone or other audio device input, AppMixer can help pull audio from applications, and some plugins (such as Synths) can even create audio themselves.

Audio Hijack Pro has been used by many to record podcasts for months now. However, with these two new features, much richer podcasts can now be created without much in the way of additional work. Podcasts made with Audio Hijack Pro can now be much more than simple microphone recording, and that's a definite step forward. Hopefully, these new updates will assist in the creation of all sorts of new and exciting content.