Export Segmentation in Final Cut 10.7 and Compressor – Faster But…

Export segmentation is a new feature in Final Cut Pro 10.7 that becomes available when you upgrade to macOS Sonoma.

Export segmentation accelerates H.264 and HEVC compression in Final Cut or Compressor by splitting export files across multiple media engines in supported Apple silicon SoCs. (This feature doesn’t affect ProRes exports.)

NOTE: Supported chips are the M1 Max & Ultra, M2 Max & Ultra and M3 Max.

I tested this new feature and discovered that, while it does make exports faster, it also has other benefits – and limitations.

EXECUTIVE SUMMARY

Export segmentation does speed exports, but less than I expected. For example, it reduced encoding times in Compressor an average of 14%.  While this feature works in both Final Cut and Compressor, it is better in Compressor. For example, when compared to exporting the same file in Final Cut, Compressor was about 25% faster.

NOTE: Part of this speed difference may be that projects were unrendered in FCP, while Compressor was compressing finished movies.

There are limitations to using Export Segmentation in Final Cut, the biggest is that, while Apple’s Help files indicate this feature supports using File > Share > Export Media, I could not get this to work. This limitation means there are restrictions on export frame sizes in FCP.

A pleasant surprise, though, was that when Export Segmentation was turned on, compressed file size was reduced an average of 27% when using default settings in Compressor.

My recommendation is to use Export Segmentation in Compressor, rather than Final Cut. For maximum performance, though, be sure to also enable additional Compressor instances in Compressor as well as Export Segmentation.

THE TEST SYSTEM

I ran these tests on an M2 Max Mac Studio with 64 GB of RAM, running macOS Sonoma 14.2.

My FCP test files were four Final Cut projects ranging in length from seven to 35 minutes. I used ProRes 4444 exports of these projects for my tests in Compressor.  All these projects/files had a non-standard frame size of 1600 x 900, which I use for my webinars, at 30 frames per second. All projects were unrendered.

I first tested the speed of exporting a single file – the 35 minute project. Then, I exported the three shorter files as a group. The results were similar for both the single file and the group.

FINAL CUT PRO

According to the Help files, Final Cut is supposed to support export segmentation when using File > Share > Export Media. However, as this screen shot illustrates, I could not get it to activate; not for a selected project in the Browser or timeline, nor in Preferences > Destinations.

This is important because this is the only export option in Final Cut which supports  non-standard frame sizes.

I could enable export segmentation when exporting using the Share setting for Apple Devices 720p or 1080p, but that forced a frame size change to the project. While export segmentation was 10% faster in Final Cut when it was enabled, this speed improvement was not worth resizing the project.

NOTE: If all your projects are 720, 1080 or UHD in size, this limitation does not apply.

Another “problem” with using export segmentation in Final Cut is that it creates a compressed master file. Seeing as we often need to create multiple compressed versions of the same master file for different distribution outlets, this means that we constantly need to go back into Final Cut to re-export the media.

A MUCH! better and, ultimately, faster way to work is to export a ProRes master file from Final Cut, then compress it using export segmentation in Compressor. The benefits to this workflow are:

• FCP creates a high-quality master file for archiving and all future compression
• Avoids going back into Final Cut and accidentally changing something simply to re-export new compressed versions
• Compressor is faster than FCP at encoding
• Compressor takes advantage of export segmentation
• Compressor also takes advantage of running multiple Compressor instances to compress multiple files at the same time

COMPRESSOR SETUP

Depending upon the chip inside your computer, Compressor supports running multiple Compressor instances. (This feature applies to both Apple silicon and Intel systems.)

This means that if you are compressing multiple files at the same time, Compressor will compress them in parallel, thus saving time. This is illustrated in the screen shot above where all three files are being encoded at the same time.

To enable this, open Compressor, then go to Compressor > Settings > Advanced and click the “Enable” checkbox. (It is off by default.) I recommend setting the number of instances to the maximum, which varies by chip.

NOTE: If performance degrades too much, lower the number of instances.

To enable export segmentation, select a compression setting applied to a clip or in the Custom Settings panel.

Go to Inspector > General and make sure both Allow export segmentation and Optimize for Network Use are checked. (Optimize is generally off by default.)

NOTE: You can’t change these settings for a default compression setting, but they can be changed for custom compression settings or any setting applied to a clip.

Finally, click the Inspector > Video text button in the Inspector, scroll down near the bottom and uncheck Multi-pass. (It is enabled by default.) If this is checked, it disables hardware acceleration which is the exact opposite of what we want to do here.

THE RESULTS

When I apply the default Social Platform > HD 1080p setting to my test files, which supports variable frame sizes, encoding times are reduced 10-16%, while still preserving the non-standard frame size.

What’s MORE impressive is that compressed file sizes are, on average, 26% smaller when using a default compression setting and export segmentation is enabled. When I apply one of my custom settings, which are tuned for small file size, compressed files are still smaller by about 1%.

SIDE NOTE ON SYSTEM RESOURCES

(Click to view larger image.)

The reason for the speed increase is that FCP/Compressor offloads the encoding to additional media engines which are a separate section of the Apple silicon SoC.

Notice in this screen shot that:

• Three instances of Compressor (the background process) are encoding simultaneously.
• The CPUs are decidedly not busy.
• The GPUs are busier when Export Segmentation is enabled (left arrow), than when it is off (right arrow).
• The system is still processing 500 MB/second of data. (All media was stored on an SSD RAID to maximize performance.)

SUMMARY

Export segmentation is faster, without question. But it works best when used with Apple Compressor, rather than Final Cut Pro. Since this is a Compressor/Final Cut Pro feature, rather than macOS, you won’t see the same results using Adobe Media Encoder or Handbrake.

NOTE: An M-series Ultra SoC, because it has four media engines, rather than two in the Max, would be significantly faster, but, as I don’t own an Ultra computer, I don’t have a way to test this.

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