This tutorial solves a tricky problem – how to broadcast two video sources into a live streaming broadcast system. The example used here is you and a partner on Skype video. Requirements to be met:
- Video and audio of both of you to be streamed
- No lag (no more than you normally get through Skype) between the two of you so you can have a normal, fluid conversation
While your audience will see you and your partner’s voice and video, and you will be able to see real time both of your video streams, your partner will,be able to hear you, but they will not be able to see you.
Tools You’ll Need
A Mac on your end with a video source for yourself (iSight or other webcam)
A willing partner with a Mac, PC or Linux machine on the other end, along with a webcam
Skype (free) from http://skype.com on both ends
A good broadband connection between the two of you
Camtwist software (free) from http://allocint.com
Audio Hijack Pro ($32) from http://rogueamoeba.com(or some other tool that will pass audio from an app to a virtual audio source)
Ustream account to broadcast the video at http://ustream.tv (or this would also work in Stickam)
Soundflower (free) from http://cycling74.com
I’ll not explain how to install each of these, the links above will take you to the various websites to learn how to download and install the applications.
High Level Explanation
You’re going to use Camtwist to capture a portion of your desktop. In that portion you’ll be displaying the video of your partner from Skype. the other half of that screen area will look blank to you, but in Camtwist you’ll also display picture in picture from your webcam. Camtwist will then be the video source that gets plugged into Ustream. Likewise you’ll use Audio Hijack Pro to combine your voice and your partners voice from Skype into a single audio source to pipe into Ustream.
We’ll start by setting up Camtwist to record the screen and PIP, then we’ll set up Audio Hijack Pro to capture and launch Skype. Then we’ll go into Ustream and set the audio device to AHP and the video source to Camtwist.
Camtwist – Set Up Picture in Picture
1 – Under Video Sources, double-click Webcam
2 – at the bottom click on PIP (for Picture in Picture)
3 – You should see PIP Webcam under Effects in Use now
Note that Camtwist will be in control of your camera as soon as you turn on PIP.
Camtwist – Set Up Desktop Capturer
1 – Under Video Sources, double-click Desktop
2 – You should see Desktop under Effects in Use now
3 – Uncheck Full Screen, which will make the Select Capture Area button available to you
We’ll adjust the capture area of the desktop later. Note that you can use a secondary monitor for the screen capture if you like by changing This Screen to a different monitor.
Audio Hijack Pro Setup
We need to pipe all sound through to Soundflower (2ch).
1 – Add Skype in the left column by clicking the plus sign at the bottom left
2 – click the Effects Tab
3 – click Effects, and choose auxiliary Device Output
Set Auxiliary Device Output to Soundflower (2ch)
This will bring up a window where you can choose the Device output, select Soundflower (2ch). Leave the Source pulldown alone. Close that popup window, and then click Hijack in the upper left (with Skype still selected).
the last step will actually launch Skype.
Connect to your partner into an audio only chat, and tell them to click the Video button. You will not be able to click yours because Camtwist "owns" your camera for the Picture in Picture. This means that they will be able to hear you but not see you.
You’re almost there! Now go into Ustream to your video channel and click Broadcast now. Accept the Flash request. Under Video Source choose Camtwist, and for Video choose Soundflower (2ch).
Now comes the fiddly part. Go back to Camtwist and click on Desktop under Adjust Settings and click on Select Capture Area. This will give you a rectangle that you can resize and move. Move your partner’s video screen from Skype into one half of that capture area, and resize the capture area and their video until it looks good. Don’t click Done on the capture area yet.
Now click on PIP under adjust effects, and slide the little black box around until it’s in the Capture Area too. There’s a slider at the top of that window that allows you to increase the size of your video until it matches their size. This takes a few minutes to get it just right but it’s doable as you can see above.
Double check that when you each talk you see the VU Meter above moving for both of you. Got it all set? Click Start Broadcast and you’re done!