And now on with my proposals (one post for each).
FIRST
In the thread Output Transform Naming from last May, I had proposed to homogenize the naming convention of Output Transforms, (as well as other Academy-provided color transforms) and to label each with a UID. It seems that these ideas are now getting momentum. For LMTs, there’s now the definition of a “LMTid” referenced in the IMP with the <adsm:LMTId>
.
Good― but this is still incomplete to me: why not adding UIDs for the associated Output Transforms as well?
On a generic side, I proposed to add UIDs in every CTL or CLF that defines a color transform (at least in the official Academy-provided ones) in the form of a hash, via a TransformHash
keyword.
As pertains the ADSM here, my suggestion is to have this referencing feature more “consistent” among the LMT and the Output Transform and, above all, with the whole ST2067-50 standard.
In App#5: ACES §8.2.4, in fact, zero or more “ACES workflows” may be defined by describing a reference/mastering device (i.e. functionally, an output transform) via the <ACESPictureSubDescriptor>
element in the CPL file. It seems that may reference using Output Transforms only (by their TransformID, plus additional color-metadata, which may, alone, be potentially insufficient or inconsidted with the ODT).
Instead, in the ADSM draft above (§5.4), my understanding is that output profiles are defined in the SCM file (rather than in the CPL); each “workflow” is associated to an LMT (referenced via a UUID) and an OutputTransform (referenced by Academy name, i.e. the TransformID).
To sum it up, I believe both optional features solve the same purpose (i.e. providing a complete, stable description of possibly-multiple viewing/mastering environments for the IMP) but propose two radically different implementations. This is due to the two proposals coming at different times.
I have a few ideas on how to homogenize them, but I feel keeping both (the feature in ST2067-50 §8.2.4, and the one in S-2008-001 §5.4) is redundant, inelegant and even possibly ambiguous: what if both features are present in an IMP but refer to different declinations of the same output-referred profile?
Please let me know if some one else also feels this should be adjusted.