NLE round-trip
Proxies your editor can relink, timeline formats read and written, and what happens when TRNSCODE writes to a project file you own.
A transcoder that hands back files your editor cannot reconnect to has moved the problem rather than solved it. This page covers what TRNSCODE does to stay inside your existing edit workflow.
The shape of a round-trip#
Two directions, and it is worth being clear which one you are in.
- Out — you have camera originals, you want proxies to cut with. TRNSCODE produces them in the format your editor expects, named and structured so relinking works.
- Back — you have a cut, and you want the finish to come from the originals rather than the proxies. TRNSCODE reads your timeline to learn what is actually used.
Formats read and written#
| Format | Used by | Direction |
|---|---|---|
| FCPXML 1.10+ | Final Cut Pro, and DaVinci Resolve via 1.10 | Read and written |
| FCP7 XML (xmeml) | Premiere Pro — the legacy interchange format | Read and written |
| CMX 3600 EDL | Effectively every system, as a lowest common denominator | Read |
| AAF | Avid | Read, for cut points |
| OpenTimelineIO | Pipeline tooling and Hiero | Read |
Cut points from a timeline tell TRNSCODE which parts of a source are actually used. On a long camera roll where the edit uses two minutes of a forty-minute take, that is the difference between conforming what you need and re-encoding everything.
Proxies and reattach#
Seven proxy presets are named for the application that will open them — Avid DNxHD 36 and DNxHR LB in MXF, Final Cut ProRes Proxy, Premiere in H.264 and ProRes, and two for Resolve. See Choosing a preset.
Generating the proxy is the easy half. Reattaching is where products usually fail, so there are dedicated reattach paths per editor rather than one generic mechanism: Resolve, Premiere and FCPXML each get their own, because each application locates and matches media differently.
The output is a sidecar file your editor opens to reconnect — you are not asked to relink clip by clip.
The reattach path is colour-managed rather than a naive transcode. A proxy that does not match the original's colour interpretation will have you grading against something that is not what you will finish from. Check one proxy against its original before proxying a whole shoot.
Writing to your project files#
Some operations write to files you own — a Resolve project, an FCPXML, a Premiere project. This is the most dangerous thing the software does, and it is worth knowing exactly what protects you.
Before any write to a customer-owned file, the current contents are snapshotted and recorded with a checksum. Restoring is a single operation against that record.
Content is written to a temporary file and then moved into place, so an interrupted write cannot leave you with a half-written project file. Either the old version is intact or the new one is complete.
Snapshots are recorded, not just written to disk. What was touched and when is visible in the activity log rather than something you have to reconstruct.
These protections cover the file. They do not cover an application holding it open with unsaved state. Close the project in your editor before running an operation that writes to it.
Resolve database relink#
There is a path that connects directly to a Resolve project database and relinks media in place, rather than going through an exported XML. It is the most convenient option and the one to be most careful with.
This writes directly to a customer's Resolve project database. Two gates stand in front of it, and both are deliberate.
Schema gate. The connector inspects the database schema when it opens and refuses to operate against a version it does not recognise. At present it ships knowing one synthetic test schema. Real Resolve 18, 19 and 20 databases are enabled only after an operator has hand-verified the schema shape against an actual installation.
Dry-run gate. A relink will not execute unless a dry run was performed first and its result is passed to the real operation. You cannot run this blind.
The practical consequence: do not plan a facility workflow around direct Resolve database relinking today without confirming your Resolve version has been verified. Until then, use the XML round-trip — it goes through the same backup protections and does not touch the project database at all.
Submitting from a timeline#
Rather than submitting file by file, you can hand over a timeline and let TRNSCODE work out the jobs. An OpenTimelineIO timeline is walked and turned into a set of jobs covering what the edit references.
This suits conform and finishing work, where the question is not "encode this file" but "produce everything this sequence needs". It is also the path that scales to a facility, since it removes the operator step where someone reads a list and types paths.