AV Foundation in OS X El Capitan adds movie editing code for developers
Thursday, 11 June 2015
The Apple WWDC 15 session video on AV Foundation shows there are new features for developers who want to manipulate QuickTime movies on the Mac.
Some notes from the video:
New version of AV Foundation provides new classes for applications to edit QuickTime movie files.
Open QuickTime movie files and perform range-based editing on movies in tracks.
You select a segment of a movie and copy it into some other movie.
Add and remove tracks (tracks in QuickTime can refer to any time-based information, such as subtitles, GPS info, camera metadata)
Associate one track with another - such as saying that this track is the chapter break information for that track.
Add or modify movie and track metadata.
Create movie files and URL sample reference movie files.
'QuickTime movie' means data in a file that conforms to the QuickTime movie file format or ISO base media file formats that were based on QuickTime such as MPEG-4.
Sample data (audio and video content) can be in files separate from the QuickTime movie.
Movies that reference external media are 'fragile' - if the media is deleted or moved, the movie cannot play.
AV Foundation can now update an existing movie file without worrying about the sample data. That means edits, tracks and metadata can all be changed if the samples stay the same - "In place editing" (URLs in the context of AV Foundation are usually describe the location of files in connected storage)
A example project that shows how an application can combine many gigabytes of footage with metadata.
What does this mean for non-developers?
Good news for post production people who need developers to make applications that support complex workflows, and for those that hope existing tools will get useful new features.
Most understated 10.11 feature here is "edit in place". No longer have to re-export entire file for trivial change. http://t.co/jqmjlnVTWU— Digital Rebellion (@digitalreb) June 11, 2015
Digitial Rebellion are the makers of Pro Media Tools for Final Cut Pro, Avid and Adobe software.
Before AV Foundation QuickTime libraries in older versions of OS X were able to manipulate QuickTime reference movies. These were small files that were able to represent complex edits of multiple external media files. Reference movies are much simpler to work with that gigabytes of video and audio footage.
Maybe it’s time to do a quick course in Swift so you can make your own post production OS X applications!
OS X for now
Note that the screenshot shows that these new features are OS X Capitan only (the OS X logo in the top right of the screen). Once they're available on iOS, tools for iPhones and iPads will be able to do much more with movie files.