I have found a way to transfer a live video screen capture from one Mac to another Mac using DV over Firewire.
This might be useful for VJs who want to mix video from two computers without using a capture card – the 5$ in the title of this post is for buying a Firewire cable.
Have a look at this video tutorial or read on for a text version – sorry about the less than optimal video and audio quality – this is my first attempt at doing a tutorial:
First of all you need to download a couple of components which I have collected in a handy zip file: DV screen capture components
Here are the links for the original sources of the components in the zip file:
Please be aware that as I have not created the software I have no way of making changes or helping out if this hack does not work for you.
1. Connect the two Macs with a Firewire cable.
2. Download the software and start up the VirtualDV app on both computers. This is to fool the computers into believing there is a hardware DV device connected
3. Unpack the v002ScreenCapture.plugin.zip file and install the plugin into /Library/Graphics/Quartz Composer Plug-Ins
4. Start up QuartzComposerLiveDV on the computer that you want to capture video from.
7. Check that it works by going to the receiving computer and open Quicktime Player. Open the Recording tab in the Preferences pane of Quicktime to check that a new video source has been created.
Things to note:
- I have only tested this on Leopard. Let me know if get it working on other versions of Mac OS.
- There is a visible delay as with other DV sources. This is because DV is a compressed format and so it also takes some CPU resources on both machines
- No sound is transmitted although sound is a part of the DV codec. I think this i because there is no sound included in the QuartzComposerLiveDV app.
- It’s only possible to capture the primary screen due to the way that v002ScreenCapture works.
- Keep the QuartzComposerLiveDV app visible – if you go apple+H the DV signal stops.
- You could also connect a DV camera and record the screen cast if that is of any use to you…
- Or you could load up any other Quartz Composer file in QuartzComposerLiveDV and send that instead. (I tried this and not all QC comps work. I am not sure why…)