Marker support missing.. What happened.

[Antti N]

Anti - I think your markers have been discarded because they are placed behind LFOC?

720 frames are 30s - your markers are set at 30s,35s, 50s and 55s.

Yeah, just realized this myself...

I can confirm that it's working as expected, as long as the marker timecodes are set within the content's time. Sorry for the stupid mistake!

[Carsten]

No big deal. I just created a Mantis entry. As currently they are discarded if set wrong, nothing is really broken.

I also just created a Mantis feature suggestion entry to show markers in the player if present.

[Antti N]

This got me wondering... Most people would probably consider moving credits a part of end credits. Shouldn't LFEC and LFMC be set at the same timecode then?

Or does the term "end credits" specifically refer to just the "main" end credits segment that appears before the rolling/moving credits start, so that FFEC < LFEC < FFMC < LFMC? The spec doesn't seem to be entirely clear on this.

[Carsten]

I just had to think about this a bit as well. I remember seeing a proper explanation of these markers somewhere, I have to look it up.


I think these terms are based on practical habits in the cinema industry. As there very often the most important names are given in static end credits, often during the final live action, and then the crowd names are shown in rolling credits.

So, FFEC should be first, followed by LFEC, followed by FFMC, followed by LFMC, followed by LFOC.

A list is in here https://interop-docs.cinepedia.com/Docu ... l_spec.pdf

Bildschirmfoto 2021-03-17 um 13.07.22.png

But it is not explicit about end credit/moving credit interpretation. But, again, I think this is handled by common industry practice. The question is, should DCP-o-matic check these dependencies? After all, these markers are actually used to control lights, curtains, etc.

Carl - does it make sense to set FFOC and LFOC manually at all? Maybe populate them automatically from the composition?

- Carsten

[Carsten]

Hmm, that's weird - I never thought about this before - but, as it seems, Marker TCs are based on reel frame numbers. They are not specified globally for the CPL runtime, but within the reels asset list, and their timing is referenced within individual reels.

For a single reel DCP, clear, CPL time matches reel time.

For a two reel CPL though, the first reel contains only a single FFOC marker. While the second/final reel contains LFOC, FFEC, LFEC, FFMC, LFMC, but all referenced to the second reel frame numbers. When I create a three reel CPL, only the first and third reel contain a MarkerList in the CPL.

So, if you input e.g. FFMC in DCP-o-matic, you are indicating it in CPL time, but when the markers are created, they are broken down into reels, and the timing reference is shifted from CPL runtime to reel runtime.

- Carsten

[Carsten]

There is more about markers in RDD52:

8.5 Marker Tracks
When a Composition Playlist’s ContentKind value is set to “feature” as specified in SMPTE ST 429-7, both marker labels FFEC (First Frame of End Credits) and FFMC (First Frame of Moving Credits) as described in SMPTE 429-7 shall be present.
Note: “End Credits” usually refer to director and/or actor credits done in card style or heavy styled end credits sequences. If neither of these types of credits exist, this can be the same frame number as FFMC. Moving Credits usually refer to the “rolling credits”. If there are no rolling credits, can be the same frame number as FFEC.
Marker labels FFOC (First Frame of Composition) and LFOC (Last Frame of Compositon) as described in SMPTE ST 429-7, should be present for all Composition Playlists. If present, the value for FFOC should represent the first frame of the Composition and be equal to “1”. If present, the value for LFOC should represent the last frame of the Compostion and be equal to (1) frame less than the Duration value of the Composition’s last reel.

[mhm]

RDD 52:2020 has this:

8.5 Marker Tracks

When a Composition Playlist’s ContentKind value is set to “feature” as specified in SMPTE ST 429-7, both marker labels FFEC (First Frame of End Credits) and FFMc (First Frame of Moving Credits) as described in SMPTE 429-7 shall be present.

Note: “End Credits” usually refer to director and/or actor credits done in card style or heavy styled end credits sequences. If neither of these types of credits exist, this can be the same frame number as FFMC. Moving Credits usually refer to the “rolling credits”. If there are no rolling credits, can be the same frame number as FFEC.

Marker labels FFOC (First Frame of Composition) and LFOC (Last Frame of Compositon) as described in SMPTE ST 429-7, should be present for all Composition Playlists. If present, the value for FFOC should represent the first frame of the Composition and be equal to “1”. If present, the value for LFOC should represent the last frame of the Compostion and be equal to (1) frame less than the Duration value of
the Composition’s last reel.

and ST 429-7:2006:

8.3.1.1 Label

The Label element shall contain a textual representation of the marker. An optional scope attribute with default URI value of “http://www.smpte-ra.org/schemas/429-7/2 ... rd-markers” determines the permissible values of the element. If the attribute is absent or set to its default value, the content of the element shall match one of the values listed in Table 4; otherwise the content of the element is outside the scope of this specification but may be displayed to the user. Note that the string above shall be considered a simple string and applicatians should not attempt to resolve it as a URL value.

also ST 429-7:2006:

9 CPL Constraints
9.1 Content Markers

The Content Markers of Section 8.3 are intimately related to the content they describe and hence most efficiently created at the time of mastering. In fact, a human operator would have to manually scrub through the content upon reception to create the same markers in an exhibition environment.

To reduce burden on exhibition operators and devices, Table 5 lists the content markers that should be inserted at mastering, as a function of the kind of content described by the Composition Playlist. If the underlying content does not support a particular marker, e.g. a particular feature does not have title credits, then the corresponding content marker shall not be created, even if present in Table 5. No more than one instance of each marker shall be present in any given Composition Playlist.

Screenshot 2021-03-17 at 14.12.25.png

Best,
Mattias

[sup]

What composition refers to here? The actual content?

(I also wonder how this would work with those MArvel movies that have a sequence in the middle of the end credits and after that")

[Carsten]

There is no formal checking of these markers on the server. They are usually only used to read out a time code and attach cues to a time code. Once the marker has been read into a cue TC, it no longer matters what type of marker it once was. So it's no problem to put e.g. a rolling credit marker before a post credit scene. It may happen that e.g. the auditorium lights come up with the rolling credits and stay on through the post credit scene though. Depends on how the cinema creates their playlists. So far, markers are dealt with completely manual on servers. TMS may use some automatic marker extraction when generating playlists.

[sup]

My attention to this was brought by the new Alpha version (?) nagging me to include some markers when I was creating a SMTPE VF for the first time. Good that they are not necessary in the end (I still put them).

But I still have no idea what "composition" in "first frame of composition" means?