Conduit Suite’s latest 1.6.2 update (available for download through your dvGarage account) adds another application to the suite. It’s called Conduit Live for Leopard, and its raison d’être is somewhat complicated: it’s not merely an update to Conduit Live, but more like a new branch that will exist from now on alongside Conduit Live for Tiger – that is, the application that previously was simply “Conduit Live”.
Confused yet? Please bear with me as we take a quick look into Mac operating system internals…
Conduit Live uses Apple’s QuickTime programming interface (abbreviated API) for capturing live video. First released in 1991, QuickTime was a breakthrough in desktop video: it offered a standardized interface for creating, editing and playing all sorts of media formats. Since then, QuickTime has accumulated all sorts of functionality, from video capture to subtitles to live streaming to Flash playback to image filters… It has become such a sprawling and uneven collection of programming interfaces that it would deserve the title “Los Angeles of media APIs”.
As Mac OS X has evolved rapidly, Apple has been trying to evolve QuickTime along with it. The QuickTime API has a lot of quirks and old-fashioned Mac OS Classic weirdness that would deserve to be eliminated in favour of a modern approach. Unfortunately such a modernized QuickTime would ideally need to both offer all the functionality of the old QuickTime and be compatible with the enormous array of software that interfaces with QuickTime on a lower level, e.g. drivers and codecs. (The situation is further complicated by QuickTime’s cross-platform nature: it is widely used on Microsoft Windows, and in fact perhaps the most popular downloadable Windows application, iTunes, relies heavily on it.)
For these reasons, Apple has never embarked on a complete rewrite of QuickTime. Instead the company appears to have decided to introduce the new QuickTime in a piecemeal fashion. Mac OS X 10.5 (a.k.a. Leopard) contains the first new QuickTime functionality that is only available through a brand new interface and only on Mac: a new video capture API that’s officially called “QTKit Capture”.
(The old QuickTime video capture API was called “Sequence Grabber”. Considering that Apple usually gives their APIs names like Quartz, Core Image or Cocoa Touch, I have to guess their marketing department was simply too burdened to come up with more interesting names for video capture…)
The new QTKit Capture API is highly appealing on paper: not only does it offer a simplified way for programmers to access video devices, but it also allows support for the highly compressed formats such as MPEG-2 which is used in HDV and Sony XDCAM recorders. The old Sequence Grabber API was too dated to ever accomodate these formats, so QTKit Capture answers a genuine need in the Mac video community. (Final Cut Pro has previously used private device control APIs to capture HDV/XDCAM video, but these were not made available to 3rd party developers before.)
So that then is the origin of Conduit Live for Leopard: it’s the same application as before, but reworked to use the new QTKit Capture API available on Mac OS X 10.5. This allows Conduit Live to support HDV cameras – I’m really happy to be able to offer this highly requested feature!
Unfortunately the situation is not clear-cut, as the new API doesn’t fully replace the old one. The main problem is that a number of devices (cameras, capture boards, etc.) that were supported under the old Sequence Grabber API don’t work correctly under QTKit Capture. Many other devices do work superficially but their functionality is limited: the new API doesn’t give access to the Settings dialog which may be necessary to change between the card’s inputs, adjust brightness, or modify any other device-specific settings.
For this reason I can’t recommend that everyone start using Conduit Live for Leopard immediately. You should adopt Conduit Live for Leopard only if your capture device is correctly supported by the new API. (It goes without saying that if you want to use a device like HDV which was previously unsupported, then the Leopard version is the only way to go.)
For devices that previously worked fine, I would encourage you to keep using Conduit Live for Tiger even if you’re on Mac OS X 10.5.
In an attempt to clarify the situation, I’m maintaining a device compatibility chart. The URL is:
http://lacquer.fi/conduit/live-compatibility
If you have a video device that’s unlisted, it would be greatly appreciated if you could try it with both versions of Conduit Live and report your findings back to me.
(Still on the topic of naming: I realize the potential for confusion that arises from having a “Leopard” and “Tiger” version even though the Tiger version might be the one you want to use even on Leopard… I just couldn’t come up with better names for these. Clearly, calling them “Conduit Live for QTKit Capture” and “Conduit Live for Sequence Grabber” wouldn’t have helped the situation at all…)
Post a Comment