Proxy Workflows: Formats, Sizes and Relinking

The short answer

Proxies are small, easy-to-play copies of the camera files. You edit with them, and the software switches back to the originals for color and export. A good default:

• • Codec: ProRes 422 Proxy or DNxHR LB, both about 36 Mb/s at 1080p 23.976.
• • Size: half the original resolution (1920 × 1080 from UHD), quarter on a slow laptop.
• • Matching: same file name, timecode and frame rate as the original, or they won't relink.
• • Space: about 16 GB per hour of footage at 1080p 23.976, around 5% of UHD ProRes 422 HQ.

Proxy codec and size

A proxy should be cheap to decode, not just small. That is why the defaults are intraframe codecs built for offline editing: Apple describes ProRes 422 Proxy as intended for offline workflows, and Avid's guide calls DNxHD 36 (now DNxHR LB at HD) acceptable quality for editing. H.264 and HEVC proxies save space but are long-GOP, so they scrub less smoothly. Use them when storage or transfer is the constraint, for example proxies that travel to a remote editor.

Keep the proxy's aspect ratio and frame rate identical to the original. Lower resolution is fine; a different shape or rate is not.

How much space proxies take

Rates are Apple's and Avid's published figures. Proxy size depends on the proxy's own resolution and frame rate, not the original's codec: an HD ProRes Proxy is about 16 GB an hour whether it was made from ARRIRAW or from H.264. Run your own numbers in CineMath's Data & Storage calculator, or in the free bitrate calculator in your browser.

Premiere Pro

• • Make them on import with Ingest settings (Create Proxies, or Copy and Create Proxies), or later with Create Proxies on clips already in the project. The default is half size in ProRes Proxy, written as _Proxy files in a Proxies folder next to the originals.
• • They attach automatically when generated. Proxies made elsewhere can be attached with Attach Proxies, which matches on file names, extensions, tape names and timecode.
• • Switch with Enable proxies; the project keeps both versions of every clip.
• • Export uses the full-resolution media by default, even with proxies enabled.

DaVinci Resolve

• • Proxy Media can be generated at Original, Half, Quarter, Eighth or Sixteenth resolution (or chosen automatically), in ProRes, DNxHR, H.264 or H.265. The files are ordinary, portable media linked to the originals by metadata.
• • Proxy Handling switches between Prefer Proxies, Prefer Camera Originals and Disable All Proxies.
• • Link Proxy Media attaches proxies made elsewhere, as long as they have the same timecode, the same file name (apart from the extension) and the same frame rate.
• • Deliver renders from the originals unless you tick Use proxy media.
• • Blackmagic Proxy Generator watches folders and writes proxies into a Proxy folder beside the originals, which Resolve links on import.

Final Cut Pro

• • Create proxy media on import or later, in ProRes 422 Proxy (best editing performance) or HEVC (smaller files). Before version 12.3 the second option was H.264.
• • Frame size from 12.5% to 100% of the original, or capped at a maximum such as 1920 × 1080.
• • Switch in the viewer's View menu: Proxy Preferred uses proxies where they exist; Proxy Only shows only proxies. Final Cut Pro always keeps the originals.

Avid Media Composer

Media Composer's offline-online workflow is the original proxy workflow. Transcode the camera media to an offline resolution (Avid suggests DNxHD 36 for HD; DNxHR LB is the same level), cut, then relink the sequence to the camera originals or to a high-resolution transcode. The Relink command with the Highest Quality method creates a relinked copy of the sequence and leaves the offline cut untouched.

Camera-made proxies

Some cameras record a proxy next to every original, so the edit can start as soon as the card is offloaded. Blackmagic's URSA Cine, for example, records an HD H.264 proxy alongside its Blackmagic RAW files, and Resolve links the two. Camera proxies follow the same rules as any other: check that they carry the original's file name and timecode, and copy them with the originals in every backup.

Rules that keep relinking working

1. Make proxies from the final originals. Don't rename, re-wrap or trim originals after the proxies exist.
2. Keep names and timecode. Proxy and original share a file name (apart from the extension) and start timecode.
3. Keep the frame rate and length. A proxy at another frame rate or with a different duration won't link.
4. Keep the folder structure. Store proxies beside the originals or in one mirrored tree, so a relink can find them all at once.
5. Watch baked-in looks. A viewing LUT burned into the proxies makes the offline look graded and the originals look flat when you switch back. Decide that on purpose, and tell the colorist.
6. Test before the edit starts. Switch a few clips between proxy and original, and export a short sequence, on day one.

Proxy workflow questions

Next: compare proxy and finishing codecs in codecs for editing, and size the drives for originals, proxies and backups with Data & Storage.