cseidel2
commented
4 years ago I would suggest that there are two ways to look at this: 1) Compliance and 2) Loudness.
From a compliance standpoint, this is a general principle that can apply to more than just Loudness. From a Loudness standpoint, there are measurable/calculable value. For Common Metadata, I ended up with Level, Deviation and LeqM (defined at the link above).
If we're really just concerned with compliance, I would generalize the field to handle any compliance issue with controlled vocabulary maintained in the registry. IMHO, this is better handled in the registry than a standard (i.e., not 377-41). In Common Metadata we considered this a general concept across media types. For example, we can carry photosensitive epilepsy (PSE) information in video. Perhaps this should be coordinated with other MXF specs. One more step down this slippery slope: Sometimes it's important to know whether something is non-compliant or untested.
If we're concerned about measured loudness, I would suggest adding Level, Deviation and LeqM using the normative definitions from Common Metadata.
I believe all of these should be considered as part of any change.
dtatut
Request to add loudness requirements as metadata entry in essence wrapper and/or CPL as part of MCA labels.
Example common loudness standards:'
“CALM” – compliance with the United States CALM Act [CALM] “EBUR128” – compliance with EBU Recommendation R 218 [EBU-R128] “ARIB” – compliance with ARIB Technical Report [ARIB-TRB32] “FREETVAU” – compliance with FreeTV Australia Operational Practice OP-59 [AU-OP59] “AESTD1004” – compliance with [AES-TD1004] "TASA" – complies with [TASA] (trailers).
This has already been outlined as part of MovieLabs "Common Metadata 'md' namespace" documentation, which may help inform this process for ST 377-41: [https://www.movielabs.com/md/md/v2.8/Common_Metadata_v2.8.pdf]