Post Hoc Ergo Proxy Hoc

Post Hoc Ergo Proxy Hoc

As I mentioned previously, there are lots of uses for proxies: dailies/client viewing, transcriptions and more. But they’re also used for editing. I’m an editor so proxies for post is what I care most about, and I’ve had both successes and failures with them.

There are several reasons to use proxies in editing. For example, when you don’t want to send out original footage. Maybe the amount of footage is such that somebody editing offsite won’t have the storage required.

Perhaps you’re spreading a project across multiple editors in different locations. Or you’re traveling and want to work on a laptop. Because the proxies are compressed copies of the original footage, storage requirements are reduced.

Another reason for not sending out the original footage is to protect it from misuse. You might use proxies compressed with watermarks and/or timecode burned in to minimize—or at least track—unauthorized usage.

In the above examples, the workflow starts with ingesting the proxies rather than the original footage. Then—after the edit sequence is “locked”—the original footage is linked to the clips in the sequence, replacing the proxies. For that to happen, there has to be a specific link between each camera-original file and its proxy.

To ensure that link, you must make sure proxy filenames are accurate and unique. Accurate, meaning they resemble the filenames of the original clips that they represent. Unique, in that you don’t have folders and folders of files.

If the filenames aren’t accurate, you could have a mess when you go to finish. A “clip” in your sequence named won’t automatically link to the original clip if the original is named, let alone And if the clip names aren’t unique, in one folder might be confused with CamA_008 in another.

While I’m not a fan of renaming original footage, renaming might be necessary in order to relink the work. But the time to rename is before any editing starts.

Timecode becomes important particularly if you aren’t able to address unique filenames. If some of your clips were shot by a camera that starts timecode at 1:00:00:00 for every take, you could have multiple drone01.MOV clips that start at 1:00:00:00. To editing software, these clips appear to be identical.

In situations like this, relinking the original footage stops being an automatic process and moves into a tedious “one clip at a time” operation. Easy enough for a few clips, but if you have multiple days of shooting with multiple cameras, it can turn into a very long relinking job. And this all needs to happen before you can even start finishing.

Of course, you could change the timecode, especially if you want to transcode files to another codec. For example, you might have some h.264 files that you know won’t perform well during edit and that need to be converted to another format—like ProRes. During that process, you could also change the starting timecode to something other than zero.

But how can you ensure that the original footage relinks correctly? Test, test, test!

More on that next time.