Posted By Paul Kafasis on September 19th, 2005

We’ve been working on this for a bit, but everything finally got nailed down today. We’re happy to announce that Rogue Amoeba will be taking part in DrunkenBlog’s Evening At Adler, with CEO Paul Kafasis representing us. If you haven’t heard, DrunkenBlog is hosting a talk among several Mac developers. We’ll be talking about all sorts of topics, and it should be fun and fascinating.

Date: October 21, 2005

Time: 6:30 pm

Location: Adler Planetarium, Chicago, Illinois

If you don’t know DrunkenBlog, you should give it a read. For full details on the Evening At Adler, see this post. If you’re in the Chicago area, I hope you’ll join us – it’s sure to be a blast.

Posted By Paul Kafasis on September 12th, 2005

Not long ago, a user named Jonathan emailed us asking how to record audio from the voice chat application Skype, using Audio Hijack Pro. For those elite few who’ve read the manual (found under the Help menu) we detail how to record from Skype and other voice chat programs (such as iChat), enabling users to record any conversations they have. This is often used for things such as interviews or calls to relatives.

This intrepid user, however, was looking to do something a bit more complex. Specifically, he wanted to record each half of the conversation onto a separate channel. If you’re not aware, a stereo audio file contains two channels, a left channel and a right channel. In music, these channels are usually blended or mirrored, but they occasionally contain unique information.

Here, Jonathan was hoping to have the audio from Alan (the local user) on the right channel and audio from Bob (his remote conversation partner) on the left channel. When this recording is listened to with headphones, all of Alan’s audio would be heard in the right ear and Bob’s in the left.But how to make such a recording? It’s a little tricky, but we worked it out and the folowing screenshots show how to do it.

For this setup, the source in the Input tab is set to the Audio Device that Skype is using for input. This must match what’s found for the Audio Input in Skype’s Audio preferences. The output is set to Silence, to avoid echoes. The real magic occurs in the Effects area.

The top row of plugins shown below handles audio from the local microphone, Alan’s audio. In order, these plugins are PassThru, a second PassThru, Monomizer, and finally Channel Tweaker set to “Kill Left”. The PassThru plugins simply prevent this audio stream from being mixed with the second stream prematurely. Monomizer ensures that the audio stream from the input device is in Mono. The Channel Tweaker plugin removes all audio from the left side, keeping it all on the right.

The next step is to get the remote half of the conversation from Skype, Bob’s half, onto the left side of the recording. That’s what the second row of plugins does for us. Here, we have Gain set to -infinity (or, zero, to non-audio geeks) creating an empty audio stream, followed by Application Mixer pulling audio from Skype. Because of the way Skype outputs audio this will just be Bob’s half of the conversation, but you’ll need to be sure to turn on the Monitor checkbox, so you can hear the output. Then we use Monomizer, again to ensure that the audio stream is in Mono and finally Channel Tweaker set to Kill Right.

Click to hear a sample recording

So, our final recording consists of two distinct streams, Alan and Bob. Each stream is reduced to just one channel, and then they’re blended together into a single stream for the final recording. The end result is a file with Alan on the right and Bob on the left, just as desired.

This technique can be extended to almost any sort of recording. To record from two different applications, one on each channel, set up the Silence Input in the Input tab, then use two instances of the Application Mixer, one in each row. To record microphone commentary over a movie, set your movie player as the Application Mixer source. There are lots of weird and great uses for this – try it out and have fun.

Update (January 21st, 2006): A few users have mentioned that the resulting recording has a slight bit of the left channel audio on the right track, and vice versa. This is occurring because Audio Hijack Pro records MP3 in joint stereo. To get pure recordings, record to AIFF. In the future, we may add true Stereo to our recording options.

Posted By Paul Kafasis on September 5th, 2005

For over a decade now, MyMac.com has been publishing Mac news and information. With the disaster in New Orleans, they’ve turned their minds to raising money for the American Red Cross. We’re working with them, along with many other Mac companies. We’ve donated copies of Audio Hijack Pro and Airfoil to be sold at a discounted price, with all the money headed to the Red Cross.

So, if you were considering buying Airfoil or Audio Hijack Pro, now’s the time – head over to this page and snap them up. Be sure to see the first page for full details, and many other Mac products you can purchase at a discount, with all the money going to charity. Everybody wins when we work together.

Posted By Paul Kafasis on September 1st, 2005

We linked to a couple audio interviews and pieces about Rogue Amoeba back in June. This week, we’ve been featured on one of the more innovative podcasts out there, the Small World podcast.

Small World interviews subjects from all walks of life, and has had some great interviews in the past. Hopefully, ours will measure up. Head over to the site and have a listen if you’re interested, and subscribe to their feed if you like what you hear.

Posted By Paul Kafasis on August 25th, 2005

Exactly one month ago, Mike made his first post here on Under The Microscope. If you missed it, Mike presented a tour of Nicecast 1.8, the first major release upon which he’d worked. Today we brought Mike on full-time, hiring him as our first official employee. So it’s with great pleasure that I introduce to you Michael Ash, Rogue Amoeba Employee #004. You can see him to the right, holding one of our fabulous Ammo toys. Make him feel welcome, or at least like the naked rhizopod protozoan that he now is. And no, I’ve no idea how you make someone feel like a naked rhizopod protozoan.

For those who are curious and also math geeks, the first three employee numbers go to Quentin, Alex, and me. We’re not really sure who should get which though, so we’ve decided that I’m Employee #001.61803 (The Golden Ratio), Quentin is Employee #002.71828 (e, Euler’s Number) and Alex is Employee #003.14159 (π pi). One day, we’re going to have an employee database, and it’s not going to be happy to be full of irrational numbers.