Making The Right Proxies

Do you experience dropped frames either from using an underpowered computer or from editing higher resolution files with harder to process codecs? Using proxies for playback while editing can help but getting them to work can be difficult.

I previously talked about a proxy workflow with Adobe’s Premiere Pro. There are a couple of ways to start the process. This blog covers using proxies that were created either during the shoot by the camera or after the shoot by a DIT or someone else.

Once the proxies are created, it’s just a matter of attaching them to the already ingested/imported files. Even if your files are named correctly, as discussed in my previous blogs, you may still run into issues because the proxies’ audio must exactly match the camera originals’ audio.

One of the common errors is not matching the number of audio channels. If the camera file has two channels, the proxy must have two channels. If there are 5 channels in the original clip, you can’t attach a 2-channel proxy.

Unless the audio matches exactly you won’t be able to attach the proxies.
Unless the audio matches exactly you won’t be able to attach the proxies.

Beyond audio channels, you also must make sure that the type of audio channels is correct. That means a proxy with a single stereo audio pair layout will not attach to a camera original with two channels of mono audio. Why? I can only guess, but I think it relates to the way the audio tracks will be inserted into a sequence. A stereo pair has to be treated differently than two mono audio channels.

For example, if you edit a stereo clip into a sequence that has stereo tracks, everything lines up. But what if you want to edit a clip with two channels of mono audio onto those stereo tracks? How should the mono tracks be laid out? Should they be panned left and right, or not panned at all? If they are not panned, should they be summed together and put on both tracks? And if that is done should the tracks be reduced in volume?

Maybe you have answers to all those questions. But what happens when you switch between proxy playback and original playback? You can’t expect the software to change the audio routing on the fly.

It’s only a guess, but that’s my thinking on why there is such inflexibility when it comes to attaching proxies and not matching audio channels. So, you must make sure that your proxy audio matches the original audio or it won’t work.

This can be frustrating. There are cameras out there that can create proxies, but if the proxy audio layout doesn’t match the original files, the proxies won’t work unless you recompress them with the correct audio. At that point you might as well create new proxies.

Even if you recompressed, you might still run into a problem. Let’s say you look at an original camera file, see that it has four mono audio channels and then set up an encoding preset that creates reduced resolution proxies that have four mono audio channels. After spending several hours rendering proxies for multiple days of footage, you try to batch attach proxies and realize that at times no audio was recorded. Perhaps this was because of a different frame rate, or maybe the audio recording was simply turned off.

For whatever reason, now you have to search through the footage and figure out which files have audio, and which do not. It might be just a couple of files, or maybe there are a lot. So you could have just a little work ahead of you, or you may have a lot.

Next time, a better way to create proxies that work.