"How do I record my system's audio when I make a video?" We hear that question a lot, and if there was a simple answer I'd be shouting it from the rooftops (which I'm sure no one in the TechSmith office park would appreciate). There's actually more to this question than meets the eye (cue robot transformation noises).
By default, Jing for Windows uses your system's specified recording device. (Mac users, I haven't forgotten you. I wrote a post for the Mac that uses Soundflower.) The default recording device is usually the input microphone, whether you have a microphone or not. We designed Jing with quick and simple communication in mind, so it made perfect sense to us to record voice narration with our videos.
If you decide you'd rather have system audio, here are a couple of options. I want to be clear here: Jing can only record from one input source at a time. This means if you want to record system audio, you can't record voice narration on that video. Also, not all sound cards have an internal sound mixer to record (in fact, the laptop I'm working on right now doesn't have one). With those caveats in place, here's how to change your system's default recording input.
Changing your system's default recording input
On Windows XP, go to your Control Panel and open Sounds and Audio Devices. On the Audio tab, click Volume in the Sound recording section. This brings up the Recording Control. This is where things can get tricky.
If you're lucky, there's a input here labeled something like "Stereo Mix", "Mono Mix", "Mixer", or "Wave In". It could be called something else too; unfortunately there isn't much of a standard among different sound cards when it comes to what to call this. If you don't see one of these (or something vaguely similar), go to Options > Properties and if it is there, make sure it is checked. If it's not there, your sound card probably doesn't have an internal audio output that it can record from.
Use a patch cable with your line in and line out jacks
All hope isn't lost though. If you're serious about recording your system audio, I've got one more idea you can try, courtesy of Mike Curtis, my cube neighbor and fellow Jing Project blog contributor. This one might require a little investment though. If you happen to have a short cable around with two male "mini" stereo ends you can plug one end into your computer's "line out" jack and the other into it's "line in" jack. I happen to have one I use to plug my iPod into my car's auxillary stereo input that I bought for five dollars or so at a local Radio Shack. Not all computers have line in and line out jacks, but yours might. This creates a loop from your line out signal (which should be your system audio) to your line in (which you can set to be the recording source by using the method I described above).
A word of caution--be careful to use your line in jack and not your microphone jack. Your microphone jack is designed to take a much weaker signal than your line in jack. Not only are many microphone inputs mono only, but the difference in signal level creates distortion as the audio signal clips. It doesn't sound pretty, and I think it's safe to say your viewers probably won't want to hear it. :)
Hopefully one of these solutions helps you record system audio with your Jing videos. Remember, if you change your recording input in the Recording Control, you'll need to turn it back to your microphone to get voice narration with your videos.