I've been a huge fan of Rogue Amoeba products for years. They offer clever audio solutions for OS X. Rogue Amoeba's new Intermission (US$15) utility fills a role on my Mac that I never even knew I needed.
Intermission enables you to pause, rewind and skip through live audio streams. This lets you take control of any audio you listen to, regardless of application. It just works, always passively listening and ready for you to take charge.
Let's say you're listening to Spotify or Pandora, and you hear a great song. You can immediately rewind and play the song again. Intermission automatically buffers that audio for you.
Or, say you're listening to a live stream. I do this all the time here at TUAW for product announcements and financial results calls. Intermission lets you immediately skip back and review what someone just said.
This is perfect for anyone who listens to live audio from their Mac -- whether it's a sports broadcast, a talk show or a teleconference. I even tested Intermission with Skype. As long as you don't need to do person-to-person interaction, you can pause the audio, hit the restroom and pick up where you left off listening. It's brilliant.
My favorite use was when I tested Intermission with Rogue Amoeba's free LineIn utility and a headset. LineIn allows you to pass audio from the default system input to the default system output. I warn you this solution is completely impractical, but it showcases some of the coolness of the app.
Normally Intermission doesn't listen to audio entering your Mac, only to audio being transmitted and played back. LineIn re-routes audio from input to output, so you can control that audio stream with the Intermission app. With LineIn and a headset, you can attend class or listen to talks at a conference and use Intermission to automatically buffer whatever you're listening to. It basically enables you to buffer real life. Did your attention stray? You can "TiVo" back five seconds and replay whatever he or she last said.
To make this work, you have to listen through the computer, which means setting up your microphone directionally to listen out and using good earphones to avoid any feedback issues as well as cut out the overlap between the live talk and what you're hearing through the head set, but it is possible (I tested it!) and it does work.
Unfortunately, I was unable to get in touch with Rogue Amoeba while writing this review, so I'm unsure as to how long the buffer records. I suspect you can't start playing Pandora the night before in order to build up a long enough feed that you can skip songs whenever you like. Also, Intermission does not offer any record-to-file features that I could find.
For $15, I think most people will find Intermission an excellent value -- especially anyone who regularly attends internet-based conference calls and training sessions, anyone who loves listening to sports and anyone who enjoys talk radio over the net. It's a really clever app that stood up well to all my testing and tweaking.
Because of its functionality, Rogue Amoeba cannot sell Intermission through the Apple App Store. You can purchase a copy instead at the Rogue Amoeba storefront. A demo version is available for download, with a menu option for registering your product. The demo version overlays noise after 10 minutes of buffered playback.
Update: Rogue Amoeba replies, "The buffer is three hours (we do note that on the site). It writes to disk in raw audio, so that's a couple gigs of space -- we'll see what happens in the future, as far as increasing that (if we compress the audio, we can record for a lot longer, obviously), without taking up more space -- but compressed audio is harder to seek through."