SMPTE DCP and Subtitles

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John Brink
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Joined: Sun Nov 29, 2020 11:44 am

SMPTE DCP and Subtitles

Post by John Brink »

Morning all, I have received a failure from Deluxe on my SMPTE DCP with regards to a Subtitle VF File. In Cinema, all Subtitles display at the correct point in time. In DOM, all Subtitle Reels are timed correctly and play correctly. I am happy to say the error is mine, but I am reaching to to find any info regarding the SMPTE Subtitle specification.
carl
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Re: SMPTE DCP and Subtitles

Post by carl »

What failure did you get?
John Brink
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Re: SMPTE DCP and Subtitles

Post by John Brink »

Good morning,

Sorry for respond so late: This is the feedback we have received
- Timed Text resource contains one or more empty Text elements.
Timed Text XML <Text> element does not contain any text. Meaning there is an empty subtitle event.
This is for the instances of blank 'dummy' subs, they have an XML with a sub spot, but no text.

- Font files must be TrueTypeFont
this means the font file does not have the right extension (.ttf)

- Mxf AssetUUID must not match Mxf AssetID [1]
The UUID of the MXF Asset must be unique and not the same as the ResourceID, the AssetID of Timed Text XML it contains.

- Timed Text MXF duration must be equal to reel duration
The time text mxf container duration must be equal to the reel duration.

- CPL AnnotationText element missing
The "Annotation Text" field of the CPL (Composition Play List) is not present. During ingest of content, what is presented to an end user (Exhibition Manager, Projectionist, etc.) may be different to what that person sees on screen after loading.

- PKL AnnotationText does not match CPL AnnotationText ''
The Annotation Text of the PKL (Packing List) and the CPL (Composition Play List) do not match each other, or the CPL's CTT. During ingest of content, what is presented to an end user (Exhibition Manager, Projectionist, etc.) may be different than what that person sees on screen after loading. If there is a discrepancy it is possible that the wrong Packing List Annotation is part of this DCP.
carl
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Re: SMPTE DCP and Subtitles

Post by carl »

Thanks for the information! What version of DCP-o-matic did you use?
John Brink
Posts: 4
Joined: Sun Nov 29, 2020 11:44 am

Re: SMPTE DCP and Subtitles

Post by John Brink »

Hell Carl,

One of the VF Files was created with DOM Ver 1.15.79. I was asked to update/change a Subtitle and got involved. The SMPTE DCP, mastered with DOM, passed the checks.
Having said that, I also leaned on my colleagues to help: Clispter and easyDCP failed with similar issues.
carl
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Re: SMPTE DCP and Subtitles

Post by carl »

Hi John

I guess you mean 2.15.79? At least some of those problems should be gone in the current test version. I'll check them all out as soon as I can.
Carsten
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Location: Germany

Re: SMPTE DCP and Subtitles

Post by Carsten »

Deluxe does not only duplicate DCPs, but also is dominating mastering and DCP conversion. So, you may imagine they are happy to find issues in DCPs NOT created by them ;-)

There is a recent effort to standardize DCP format on a more specific level than generic SMPTE ('RDD52'). In recent test versions, DCP-o-matic is also creating files towards RDD52 compliance (and DCP-o-matic player verifies according to RDD52). Not sure how Deluxe currently deals with RDD52 constraints. They may still follow their house internal rules.
John Brink
Posts: 4
Joined: Sun Nov 29, 2020 11:44 am

Re: SMPTE DCP and Subtitles

Post by John Brink »

Hello Carl,

Yes, I understand that Deluxe will fail DCP's on any grounds... and charge for creating their own VF File.
If I may run this past you: The DCDM Subtitle Reel needs to be the same length of the Video Asset/Reel. The way I have done this is to have a Subtitle with a zero duration at the Start and End of each Reel. So if there are sporadic Subtitles and a Video Reel might not have any Subtitles, I have created a Subtitle Reel with only a Subtitle at the Start and End of the Reel with a Zero duration.
I have not yet found a way to make a "transparent' Subtitle. I am not sure this is a valid approach/resolve to the problem: DOM reflects the correct Reel Duration and is happy with the Zero duration Subtitle.

In the DCDM xml, I have inserted the Font Name in where I understand this is required: this is driven from Deluxe indicating that the Font NameSpace <LabelText>, cannot be "empty"... even though the UUID is included.

DOM 2.14.17 seems to carry this UIDD, but not the Font Name e.g., Arial
DOM 2.15.156 does not carry this information through i.e <LabelText> remains empty/not populated.

I have attached Deluxe's VF cpl for you.
Attachments
CPL_29599c07-2178-4e36-8f39-b08b9c443a13.xml
(19.92 KiB) Downloaded 18 times
Carsten
Posts: 1824
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Location: Germany

Re: SMPTE DCP and Subtitles

Post by Carsten »

There is a recognized way for the 'empty' captions/subtitle reels. Similarly to RDD52, there is recommended procedure:

https://isdcf.com/papers/ISDCF-Doc-16_E ... _draft.pdf
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