A proxy workflow for Avid, Premiere Pro and Resolve, with proxies made during upload

Camera originals are too heavy to edit from directly on most shows. A 4K ProRes 4444 file needs about 125 MB/s per stream to play smoothly, and camera RAW can need more. A proxy workflow solves this by giving editorial a small copy of every clip, cut on those copies through the whole offline, and swapping back to the camera originals for the online and color.

The weak spot is usually making the proxies. Someone has to transcode every card after it arrives, often overnight on a spare machine, before editorial can start. On CloudStudio the proxies can be made as part of the upload instead.

What an edit proxy has to get right

A proxy only works if the editing software can swap it for the original later. That means it has to match the original on the things the conform relies on:

the same clip name, so the NLE can find the original by name
the same frame rate and duration
the same timecode
the same audio channels

Picture quality matters less. A proxy has to be good enough to judge performance and timing, and small enough that many streams play at once.

DNxHR LB or ProRes Proxy

CloudStudio makes two proxy formats today.

DNxHR LB in an MXF, 8-bit 4:2:2, about 36 Mbps at 1080p24. This is the usual choice for Avid Media Composer, which works natively with MXF media. One hour of footage is about 16 GB.

ProRes 422 Proxy in a MOV, 10-bit 4:2:2, about 45 Mbps at 1080p24. This is the usual choice for Premiere Pro and DaVinci Resolve. One hour of footage is about 20 GB.

For comparison, one hour of 4K ProRes 4444 at 125 MB/s is about 450 GB. A full set of proxies for a show shot that way is around 3 to 4 percent of the size of the originals, which is why proxies can stay on fast storage for the whole schedule while the originals move to the Archive tier.

You can make both formats for the same clip if part of the team cuts in Avid and part in Resolve.

How it works on CloudStudio

1. Upload camera media to Hot storage in Transfers, and turn on "Create edit proxies".
2. Pick DNxHR LB or ProRes Proxy, and choose the Hot storage pool the proxies should go to.
3. When the upload finishes, the files go to our media workers, which decode the camera files and write the proxies to that pool.
4. Editors mount the proxy pool on their CloudStudio workstation and start cutting.

Media that is already on Hot can get proxies later from the media library, without uploading it again.

Avid MediaFiles layout

For Avid, the proxies can be written straight into the Avid MediaFiles folder layout, with video as ClipName_V1.mxf and each audio channel as its own MXF. Media Composer picks them up from the drive without an import step. On large shows, the files are split across numbered folders once a folder passes about 5,000 files, which keeps Avid’s media indexing fast.

Color: LUTs and Rec. 709

Log footage looks flat without a transform. You can apply a LUT when the proxies are made, so editors see the intended look. Without a LUT, the proxies are converted to Rec. 709. Every proxy also has its color metadata written explicitly, so the NLE doesn’t have to guess how to display it.

Switching back to the originals

The proxies are only half the workflow. When the cut locks, the online needs the camera originals for every shot in it. On CloudStudio, the post team uploads the XML from the locked cut and the conform pull restores only those originals from the Archive tier to Hot. On one docuseries episode that was 505 files and 3.88 TB out of a 115.6 TB archive, in 2 hours 34 minutes. Read the full job numbers.

Making proxies locally versus during upload

Making proxies on an editor’s machine means copying the camera media to that machine first, then tying it up for hours of transcoding. On a show with several editors, it also means deciding who has which copy.

Making them during upload means the camera media is only ever copied to one place. The transcode runs on media workers instead of someone’s laptop, and every editor mounts the same proxy pool. The camera originals can move to Archive as soon as editorial is working, without anyone noticing.

See how proxies fit into the full workflow, or read how Hot, Archive and Deep storage are split.