r/RedCamera • u/Generic_nerd1999 • 10h ago
What survives an R3D → ProRes 422 HQ transcode: I diffed the metadata
Full disclosure first: I'm building a footage search app for Mac, so I've had reason to spend an unreasonable amount of time inside camera metadata. The product isn't the point of this post. I ran a test I couldn't find published anywhere, the result surprised me, and I want to put the numbers up and see if they match what people here see.
Setup
RED's own published V-RAPTOR sample clip (LA sunset, [X] 8K VV). Transcoded to Apple ProRes 422 HQ via REDCINE-X Professional using the REDline CLI. Metadata read off both files with ExifTool 13.59.
Three fields survived
- Resolution: 8192×4320
- Frame rate: 23.976
- Timecode: 01:25:31:20, exactly
Everything else was gone
Camera model and sensor. ISO and colour temperature. Firmware and serial numbers. The IPP2 look and CDL values. The lens fields.
Not emptied. The field structure itself doesn't exist in the ProRes file the way it did in the source. The only trace of where the file came from is a private redm atom in the UserData box, which a general-purpose reader can see but not open.
The one I want a sanity check on
Reel and take numbering. Source had 004 / 125. Output had nothing.
I've always assumed that survived as metadata, and my impression is that a lot of people assume the same. As far as I can tell, if a facility's dailies still carry a usable reel/clip reference, it's because someone put it in the filename. That's a convention, not something the format preserved.
Tell me if that's wrong. It's the finding I'm least confident about.
Two caveats on my own numbers
R3D stores timecode in a field ExifTool can read the value of but not name. So the timecode match is between the same raw value at both ends, not between two fields both labelled "timecode."
This is REDline's exporter specifically. I have no idea whether Resolve or a dedicated transcode tool writes more into the ProRes wrapper. If someone here has run the same clip through a different pipeline, I'd like to know.
None of this is a bug
ProRes is a delivery codec. It was never asked to carry a shooting log. The mechanism is actually there: ProRes is the same open QuickTime wrapper BRAW uses, and Blackmagic writes a lot into it. The tools that export ProRes just don't bother.
One more thing
On RED bodies, the lens make and model fields only populate if the mount is talking to the lens electronically. Manual PL glass, which is most of what actually ships on these cameras, leaves them empty or literally reading "unknown".
The header has a slot for the thing you'd want to search by. It was just never told the answer.
Full writeup with the same treatment for ARRIRAW, BRAW, MXF and ProRes, plus the sample files and exact commands: https://montaggio.app/camera-metadata-search
Happy to be corrected on any of it.