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Tip #1130: Not All Proxy Files are the Same

Larry Jordan – LarryJordan.com

Proxies are smaller files than camera masters, but not all proxies are equal.

Topic $TipTopic

While working on my webinar this week on Multicam Editing in Adobe Premiere Pro I started looking into proxy files. By definition, a proxy file is a smaller file than the camera native file is is derived from. But not all proxy files are created equal.

  • Final Cut Pro X, for example, defaults to ProRes Proxy for all proxy files.
  • Premiere Pro provides the choice of H.264, ProRes or Cineform. (DNx is reserved for 360° VR video.)

H.264 provides the smallest files. Based on my tests, H.264 files are about 1/10 the size of ProRes Proxy, while ProRes Proxy is about 1/10 the size of ProRes 422. But, due to the GOP-compression that H.264 uses, these files are less efficient to edit; especially on slower systems.

  • If you are looking for smooth playback and faster rendering, ProRes Proxy is a better choice.
  • If you are looking for the smallest files, for example, to transfer over the web for another editor to work on, H.264 is a better choice. Just remember that H.264 will require a newer computer with a fast CPU to edit effectively.

The webinar has more details on all of these.


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4 Comments
  1. Mike Janowski
    Mike Janowski says:

    Larry, I’m no expert in using proxies, but I’ve found them quite confounding when making proxies (specifically, h264 proxies) of clips with multiple channels of audio.

    I have not done a complete diagnosis of the issue I encountered, but on a project from this past summer, I was given a metric boatload of 4K .MXF files with 4 channel audio. I imported them (and later discovered they’d been imported with “adaptive” audio tracks, another issue you ought to delve into), and then created h264 proxies, with 2 audio tracks. Upon completion of the project, I tried to reconnect. Guess what? Because my full-rez files had 4 tracks of audio, I could not reconnect them via the standard dialog, and had to resort to trashing the proxies, forcing Premiere to reconnect.

    Now, perhaps it was the adaptive audio format that screwed me up; perhaps it was my failure to use a proxy format that supported more than 2 tracks of audio. Either way, the finishing stage of a project is an inopportune time to discover this flaw in the process. I wonder if you have any knowledge or experience with these issues?

    Reply
    • Larry Jordan
      Larry Jordan says:

      Mike:

      Ouch!!

      No, you do NOT want to discover during finishing that the import process screwed up. Wow.

      Adaptive audio, as I understand it, simply means that Premiere recognizes the difference between mono and stereo files. However, the mis-matched audio channels between proxies and masters is probably the cause of the chaos. H.264 is very attractive, from a file size point of view. But it is a very limited format – best suited for distribution, not editing.

      When this is over, do a test between proxy files using H.264 and ProRes Proxy – which is designed for multi-channel audio – and let me know what you find.

      Larry

      Reply
    • Larry Jordan
      Larry Jordan says:

      Petr:

      You are absolutely correct – I forgot about this update when I was writing this tip.

      Thanks for the correction.

      Larry

      Reply

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