What Are Proxies in Video Editing? The Ultimate Guide

If you‘ve spent any time in the world of professional video editing, you‘ve likely heard the term "proxies" tossed around. But what exactly are proxies and why are they such an important part of many post-production workflows? In this in-depth guide, we‘ll break down everything you need to know about proxies – from the fundamentals of what they are and how they work, to best practices for implementing them in your own projects. By the end, you‘ll be a proxy master ready to optimize your editing workflow.

Proxies Defined: What Are They?

In video editing, a proxy is a lower-resolution, smaller file size version of an original source video clip. Proxies are transcoded from the original high-resolution camera files into formats that are faster and easier for video editing software to work with.

For example, if you shoot a project in 8K RAW video, those massive files would be very taxing for most computers to edit natively, leading to slow performance, lag, and crashes. But if you create lower-res proxy versions, say in 1080p ProRes 422 or DNxHD format, your editing software can breeze through those much more manageable files. Then when it‘s time to export, the proxies are relinked to the original high-res source files so you still get maximum quality in your final output.

Think of it like making a low-res "proxy" of Michelangelo‘s David in clay before attempting to sculpt the final marble version. The clay proxy allows you to make creative decisions quickly without wasting expensive materials. Then once your vision is realized, you execute it using the real thing.

Why Use Proxies? Common Scenarios

There are a few main reasons to use proxies in your video editing process:

1. Performance – As mentioned, editing native high-res files like 8K or even 4K can bring many computers to their knees. Using proxies, especially on lower-powered laptops, allows for smooth, real-time editing performance.

2. Storage space – High-res video eats up storage space fast. Keeping your main editing project on proxies and only reincorporating the full-res files at the end can save huge amounts of storage, which is especially helpful if you‘re working on a laptop or sharing files remotely.

3. Speed of sharing – It‘s much faster to transfer smaller proxy files over the internet or between collaborators than huge source files. This allows for a quicker collaborative process.

4. Compatability – Some newer camera formats, like RAW files, aren‘t supported natively by all editing apps. Making proxies in a universally-compatible format ensures you can edit your footage in any software.

Common scenarios where proxies are used:

• Editing 4K/8K projects on a laptop or older computer
• Projects with lots of effects/color grading that would be taxing to render at full res
• Documentaries with huge amounts of footage that would fill up hard drives
• Collaborating remotely with editors and clients
• Editing on-set or without access to the original camera files

How Proxies Work: The Technical Details

To make proxies, the original source footage is transcoded into a new lower-resolution, more compressed format. This is typically done by the video editing application, like Adobe Premiere Pro or DaVinci Resolve, though there are also dedicated proxy generation tools.

Some common specs for proxy files:

• Resolution: 720p or 1080p (compared to 4K/8K source)
• Codec: ProRes 422 Proxy, DNxHR LB, H.264
• Bit depth: 8-bit
• Audio: Untouched or lower bitrate version of source audio

The idea is to find a sweet spot that retains enough quality to make editorial decisions but is small and fast enough for smooth playback. ProRes and DNx codecs are popular because they are widely supported and still maintain good visual quality at lower data rates compared to more heavily-compressed formats like H.264.

It‘s also important that proxies match the exact frame rate, number of frames, and audio of the source clips so they can be swapped out seamlessly. Timecode and file naming conventions are often crucial for relinking proxies to source files later.

Generating Proxies Step-by-Step

The proxy creation process varies between editing apps but generally follows a similar workflow:

1. Import your source footage into the app
2. Select the clips you want to make proxies for
3. Choose your proxy settings (resolution, codec, destination)
4. Let the software transcode the proxies
5. The proxies are now linked to your source clips and will be used in the editing timeline

In Premiere Pro, for example, you can right click selected clips in the Project panel, then go to Proxy > Create Proxies. You can choose from presets or make custom settings, pick a destination for the proxy files, then start the proxy job. Once completed, toggle proxies on/off with the button in the Program Monitor.

Many apps have proxy creation built in, but there are also dedicated tools like Hedge that can automatically make proxies on import or in the background while you work.

Pros and Cons of Proxies

Pros of using proxies:

• Faster, smoother editing performance
• Ability to edit high-res footage on lower-power computers
• Saves on storage space
• Faster to transfer and share small proxy files remotely
• Standardizes footage for editing if using multiple camera formats

Cons of using proxies:

• Extra time spent transcoding proxies
• Potential for errors or lost quality if proxies aren‘t made correctly
• Confusion in project organization with multiple sets of files
• Relink process at the end can be tricky and time-consuming
• Not always necessary for simpler projects or if you have a powerful editing rig

Whether proxies are worth it for you depends on your specific project needs, hardware, and workflow. For many large-scale professional projects they are unavoidable, while smaller projects may be fine working with native files.

Best Practices for an Effective Proxy Workflow

If you do decide to use proxies, follow these tips for the smoothest process:

1. Organize – Keep your source footage and proxies in a clearly-labeled folder structure. Ensuring matching timecode and filenames makes relinking much easier.

2. Set up your proxies correctly from the start – Choose the right resolution, codec, and settings for your needs. Test out the proxies before diving into editing.

3. Quality control – Do a spot check that your proxies match the source footage 1:1 before editing. Make sure nothing got lost in transcoding.

4. Toggle on/off – Most NLEs let you switch between proxy and source files in the viewer. Use this to check your edits against the original quality.

5. Invest in fast storage – Even with proxies, you still want fast SSDs or RAIDs to optimize performance, especially when relinking.

6. Relink and render – Leave time at the end to relink your proxies to the source files for final output. Do test exports to ensure everything is connected properly.

Alternatives to Proxies

While proxies are a popular solution, they aren‘t the only way to improve video editing performance. Some alternatives:

• Using optimized media formats – Codecs like ProRes, DNx, and Cineform are designed to be edit-friendly even at higher resolutions. Transcoding to an optimized mezzanine codec rather than low-res proxies can provide better performance if your hardware allows it.

• Editing native files – With the latest CPUs, GPUs, and fast SSDs, more powerful computers can handle editing high-res files natively. Using smart rendering and timeline optimizations in your NLE can make this more feasible.

• Proxy-free camera formats – Some newer professional cameras like the Canon C500 Mark II can record edit-friendly .MXF files along with their RAW footage, eliminating the need to transcode entirely.

Proxy Support in Different NLEs

Most major NLEs support proxies, but they differ somewhat in implementation and features. Here‘s a quick overview:

• Adobe Premiere Pro – Robust proxy options for both ingest and transcoding within the app. Easy proxy attach/detach.
• Final Cut Pro X – Magnetic Timeline makes proxies simple, with options for Proxy, Optimized, or Native media. Background transcode is handy.
• Avid Media Composer – Uses its own DNX codec for efficient proxy editing. Proxies can be created on import or in the background.
• DaVinci Resolve – Newer proxy options to optimize performance. Can generate proxies on import and link to camera originals.

Overall, proxy support is solid in most apps, so the best choice comes down to your preferred NLE and existing workflow.

To Proxy or Not to Proxy?

We‘ve covered a lot about proxies, but how do you know if you should use them for your project? Here are some questions to ask:

• What resolution and codec is your source footage? If it‘s 4K and higher, or in a less edit-friendly format like RAW or H.264, proxies could be beneficial.
• What‘s your editing hardware? If using a laptop or older machine, proxies will likely improve performance. If you have a powerful desktop workstation, you may be able to edit native files.
• How complex is the project? Lots of timelines, effects, and color work will be faster with proxies. A simpler project may not need them.
• Are you collaborating with others? Proxies are very useful for sharing and editing remotely with a team.
• What‘s your output resolution? If outputting in 1080p, editing 4K native files may be overkill.
• Do you have time to transcode proxies? Don‘t forget to factor in time for that extra step.
• How much storage do you have? Proxies can help save space on small SSDs.

Conclusion

We‘ve learned that proxies are lower-resolution versions of source video files that can greatly speed up editing performance and collaboration, especially when working with high-res footage or on lower-powered computers. While they add some extra steps and complexity to the post-production process, proxies are an indispensable tool in the professional video editor‘s toolkit.

By understanding the benefits, best practices, and different implementation options, you can build an effective proxy workflow that allows you to work smarter and faster – without sacrificing an ounce of quality. So next time you‘re staring down a mountain of 8K footage that needs to be cut yesterday, remember: proxies are your friend.