Keep interpretation and transformation separate
A production colour review begins with two questions: what do the stored samples represent, and how is the next stage interpreting them? A label can describe samples without changing them. A conversion changes sample values for another representation. Confusing those operations can produce a file that advertises the desired delivery format while carrying inappropriate values.
Build a small worksheet for the owned source: camera or export provenance, stated primaries, transfer characteristics, matrix coefficients, range and any unknowns. Treat an absent field as unknown. Do not fill it from the filename, resolution or a visual impression that the picture looks cinematic.
Rank evidence before overriding metadata
A trustworthy capture setting or prior export record can explain the intended interpretation. A copied tag from another file cannot. If records conflict, preserve both and identify the earliest stage where the disagreement appears. A container label and bitstream label need not be accepted uncritically merely because a tool prints them.
Use a short authorised passage containing neutral tones, faces, shadows and bright detail. Keep the monitoring route fixed while comparing candidates. Changing the display mode alongside the export creates two moving parts and makes the result difficult to attribute. Screenshots can also pass through additional colour handling, so retain the actual media sample.
Decide what kind of change is justified
Suppose an editor has reliable documentation that the source was created for one colour representation, but the export omitted its identifying metadata. A correction candidate should restore that known description. If the delivery requires another representation, plan an explicit conversion with known input and output assumptions. Do not guess the input merely to make a filter stop reporting an error.
FFmpeg's colour-processing documentation includes conversion controls; use the installed tool's help for the exact operation. A useful processing note states the interpretation supplied, transformation performed and output description written. MDN's VideoColorSpace reference, by Mozilla Contributors under CC BY-SA 2.5 or later, identifies separate colour-description properties. Those properties do not prove a conversion occurred.
Accept the handoff, including uncertainty
Review the delivered file in the intended production destination and a second documented route when appropriate. Confirm that the worksheet matches the output report and that the image has not acquired unintended clipping or a large shift in neutral tones. A visually pleasing preview is not a measurement of mastering accuracy.
Keep an unchanged source, a labelled candidate and the processing record. When evidence is insufficient, return an uncertainty with a reproducible sample rather than permanently baking a speculative correction into the only master. This keeps a later colour decision possible.
Questions answered
Does adding a BT.709 label convert the pixels?
A label alone is not a pixel conversion. Check what the selected operation actually changes.
Can resolution identify the source colour space?
No. Use provenance and explicit media information rather than deriving colour interpretation from width and height.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.