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inputing multiple dv cameras is now possible on mac, why not jitter?

Oct 29 2009 | 10:50 pm


I have been doing some research on getting multiple dv cameras into jitter. As of now it seems that only IIDC capable cameras or converters are accepted when one wants multiple inputs on a mac.

After pursuing other software I have found that Grand VJ by Arkaos can accept multiple camera inputs on a mac and they claim this is due to the new QTkit offered by apple.

Can jitter please incorporate this technology in future versions?

I quote from the Apple Developpers site: "Using these classes and methods, you can record professional-quality audio and video content from one or more cameras and microphones, including USB and Firewire devices, as well as DV media devices."

From the Arkaos Grand VJ forum: "Mac: changed the camera / streaming support to use new QuickTime API (QT Kit capture instead of the old QuickTime streaming). Thanks to this you can now use multiple DV Cameras, HDV cameras, HD acquisition is possible with a PCI card (ie Decklink Intensity Pro) etc."

praying for multiple high quality camera input capabilities on his MacPro…


Oct 30 2009 | 12:57 pm

Telestream’s Wirecast is another example of Quicktime applications that support multiple firewire cameras. They officially support two cameras per bus, which I’ve tested (and confirmed) using a pair of Canopus ADVC110s.

Oct 30 2009 | 2:37 pm

the vj software modul8 at version 2.6 is also able to use 4 cams simultaneously.

Oct 30 2009 | 5:10 pm

Have you guys then been able to import the input stream into jitter?

Nov 01 2009 | 7:26 pm

Not to speak for cycling, the following is speculation:

QTkit is a steaming, complete fucking pile of horsehit. Ok, that may be a bit strong. It does some things very well, but does not let you get at low level internals easily, and while QTkit makes some things super straight forward, getting speed as well as full functionality out of it is somewhat maddening.

Im assuming Jitter is built using ye-olde Quicktime library, which does (almost) everything you could want, but is being replaced slowly by QTkit. QTkit wraps up some things in Quicktime (the library) and fixes some issues at the cost of not always exposing some of the deeper, lower level functionality, basically some things are Black Box you can’t really get to, since bugs fixed in Quicktime (library) are done behind the scenes.

So, I imagine that some parts of Jitter would have to be re-written to use QTkit to gain the multi-DV compatibility, but I know for certain that QTkit does *not* expose natively some of the lower level stuff like IIDC camera settings dialog and things like that. On top of it, there are still some potential issues with multiple DV devices. Ive toyed a lot with QTKit and multi in and it is, in my experience, rather flakey.

Now, you can mix/match older Quicktime library + QTkit code to get around some of these issues, but I know there are gotchas and caveats when doing so. Add to the complications of the new 10.6 Quicktime X stuff (which changes QTkit behind the scenes even more), and it gets even nuttier.

But, remember, QTKit is (as far as I know), not available on Windows (No Cocoa apis although there is Obj-C), so that adds an additional complication since Jitter needs to support both platforms. In short, its complicated, and Quicktime in general is not heping.

Its really a shame about QTkit and Quicktime in general, it could be so awesome, yet fails when you get kind of deep into it if you need cross platform compatibility, and dont want to kill yourself.

Anyway, again, this is just speculation on the internals, I have no special insight except my experience.

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