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wolfgangw / backports

Deep inspection of digital cinema packages
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png subtitles #43

Open liloneum opened 10 years ago

liloneum commented 10 years ago

In case of cinecanvas png subtitles, dcp_inspect only checks the presence of the assets in the assetmap. The assets must be present in the pkl too and shall be validated as any other.

wolfgangw commented 10 years ago

No, the DCP format does not provide that guarantee. While uncommon a DCP with

dcp_inspect builds a dictionary from a given asset map. It will lookup assets referenced by any related packing lists and do whatever the packing list's PoV allows (asset file presence and hash value).

Playback completeness is checked from the composition's PoV later on. Which is the single perspective that allows it.

liloneum commented 10 years ago

Very strange. EasyDCPPlayerDemo 2.0.4 accepts both DCP with or without images declared in pkl file without check errors but does not succeed to display the subtitles correctly. NeoDCP will not display the png files not declared in the pkl with this error: "Unable to load image file". I will have to check it on several servers...

Does your PoV mean that you even don't have any obligation to declare your font file in the pkl?

liloneum commented 10 years ago

I tried very quickly on a Doremi dcp2000 both packages. Unfortunately, I did not write the error but the message was something like "can not find the element" if the png files are not declared in the pkl (no error if declared). But the subtitles are displayed anyway.

wolfgangw commented 10 years ago

I'll agree that the standard use case will have exactly AssetMap's N assets in the PackingList as well. So there could be a hint in the case of a mismatch.

Keep in mind that the format allows for multi PKL in one spot as well as PKLs spread out over more than one distribution spot.

Apparently systems in the field handle ingest differently. Some ingest from PKL, some will try (and sometimes fail) to ingest from CPL.