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AVFoundation gets massive upgrade in Yosemite

As Final Cut Pro X – and other modern video apps – are built on Frameworks from the core OS, those Frameworks sometimes provide clues to Apple’s thinking. One that we care a lot about is AVFoundation, which is the modern replacement for QuickTime at the application and OS level. We’ve seen this in the transition from QuickTime Player 7, which is built on QuickTime (both QTKit and the older C API). Unfortunately AVFoundation has lacked many features that are essential for video workflows, so I watch the features added to AVFoundation as a way of understanding where video apps might go.

Firstly, there has been a massive update to AVFoundation in Yosemite, and it appears we get reference movies back.

At each Operating System release, Apple provides documentation that highlights the differences in the new Frameworks, compared to the Framework in Mavericks. The AVFoundation “diff” is an interesting read. It’s a lot to go through and it was only released yesterday with the release of Yosemite, so I’ll limit myself to two observations.

There is a lot of new audio functions. A lot, as in heaps. What is particularly interesting are:

AVAudioMix, which already existed; and



Just a wild guess here, but if there were plans for a more comprehensive audio mixer in Final Cut Pro X, they might have been waiting for the foundations from the OS Frameworks. I am still hoping for a roles-based audio mixer panel in Final Cut Pro X.

The other interesting observation is the addition of:

AVMovie with support for AVFragmentedMovie!

We’ve had AVAssets and AVCompositions in AVFoundation up until now, which do not support reference movies. It seems a reasonable inference that an AVFragmentedMovie is what we’d have called a QT Reference movie in the past. Unfortunately there’s no documentation for this new addition to the Framework.

If you read through the additions and changes to AVFoundation document, you can’t help but notice that AVFoundation Metadata also got a fair bit of attention.



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15 responses to “AVFoundation gets massive upgrade in Yosemite”

  1. cseeman


    Might this also be a missing link needed for round tripping to Motion?

    1. Philip

      Roundtripping with Motion in the old Studio was quite complex and used Reference Movies to send the background media to Motion, then used a custom QT component to send back a “MOV” which was really an XML project file being interpreted as a movie. Neither mechanism exists, unless AVFragmentedMovie is indeed a reference movie.

      The other part has no modern equivalent so there would need to be a completely different mechanism developed. While I’d like to see a better “send to Motion” equivalent I’m not holding my breath, although if this does signal the return of reference movies, then sending to Motion becomes possible. A final file would need to be rendered to go back.

  2. Great info as usual, Phillip!

    1. Philip

      I remember watching that session shortly after WWDC. Interesting, but couldn’t think of an application for it in our field. Yet.

  3. I think the AVFragementedMovie API addition enables the creation of movie fragments whilst capturing video. This allows the partial movie to be readable before completion and also readable in the case of unexpected interruption. So a useful change but not reference movies!

  4. JPM Editor


    Could this also be the missing piece in the AVFoundation kit that was necessary to allow FCPX to consolidate only the used portion of clips?

    If that were the case, this could help improve the media management in FCPX even more!

    1. Philip

      I think you’re right about AVFragmentedMovie, but I do believe there is support for Reference movies as well.

    2. Philip

      I don’t think AVFragmentedMovie has anything to do with consolidation. That has been possible all the time, but the decision has been made not to do it. I do not expect Apple to ever create a “consolidate only used media” tool. There is an (accurate) assumption that drive space is abundant and cheap.

      1. Marcus Moore

        Many popular recording formats wouldn’t even allow you to trim used media. I don’t see how you could do it with RED, ARRI, SONY, or C300 Media. Unless you’re Managing Optimized ProRes transcodes.

  5. Shameer M.

    So what are your thoughts on the new Retina iMac, in general and in terms how you think it FCPX will perform on it?

    1. Philip

      I like the idea of a Retina iMac but I don’t have any data on how FCP X would perform on it, so I’m going to reserve judgement for a while.

    2. Top of the line 5K iMac appears to be faster than lower end Mac Pro:

  6. Kamil Dobrowolski

    This is all very exciting under the hood updates that will hopefully materialize in better audio tools within FCPX. It’s also interesting how iMovie received an update the same day as OSX 10.10 release, with features like HD Email mail drop and a handy bitrate slider for exporting H.264 media. I’m sure we’ll see these features added into FCP 10.1.4 and course force 10.10 as the minimum requirement to gain access the latest features. I personally am already loving the 5GB email option and find it far more convenient than sending a Vimeo link with password or using wetransfer, dropbox ect.. for large file sharing. Soon it will be a hotkey away from spitting out a feature project right into the body of an email.