How to sync your h.264 Canon 5D Mark II rushes *before* transcoding them


I’ve been dying to work with a DSLR for video for a long time. I finally did. It was a headache and a half. Part of this was due to my own rustiness at recording dual system audio in the field, but most of it was because of the technical issues of syncing the externally recorded audio tracks to the video rushes that come out of the camera.

I knew what I was getting into; the vagaries of this syncing process are well documented. What I wanted to avoid, though, was transcoding ALL my rushes into Apple ProRes 422 before syncing the sound–because that would tie up my computer for 150 hours, according to Compressor. And not to mention blowing up the file sizes to Galactus-level, too. I’m not editing this footage myself, just handing it off, so it made more sense to sync the rushes in the much-smaller native h.264 format that comes right out of the Canon, and let my client transcode on their (let’s hope) much faster machines.

So everyone knows that the key to syncing this kind of footage is an indispensable program called PluralEyes. The trouble is, every time I ran it on the h.264 files in Final Cut Pro, I got massive drift problems – the audio would only stay in sync for the first couple minutes.

After much trial and error, here’s what you do to successfully run PluralEyes to sync h.264 rushes (BEFORE transcoding) from a Canon 5D Mark II with externally recorded audio tracks:

1. Download the Easy Setup designed for syncing ProRes footage.

2. Start up FCP with the aforementioned Easy Setup. Import your h.264 rushes, and make a new Sequence.

3. Press Apple-0 to open the Sequence settings. Change the Compressor from Apple ProRes 422 to H.264.

4. Drag your h.264 rushes into the timeline. When it asks you if you want to change the Sequence setting to match the clips, select NO.

5. Drag your audio tracks in and run Plural Eyes as usual. Presto, synced rushes that aren’t 14,000 GBs big and didn’t tie up your computer until the next millennium.

I *only* got this to work by using the modified ProRes Easy Setup. When I tried to build my own Sequence settings from scratch to match the h.264 rushes, the sync drift persisted. No idea why. So hopefully this post will save you some trouble if you are in a similar situation.

One Response to “How to sync your h.264 Canon 5D Mark II rushes *before* transcoding them”

  1. Your procedure makes sense but it is also important to note that whenever you change the Easy Setup, you also have to:
    1. Re-start FCP
    2. Start a new project
    3. Import your media from scratch into that new project.

    Sounds heavy-duty I know, but it is the only way to guarantee that the right frame rate sticks.


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