1.78 in Version 2.12.6

[morganburkebeyers]

Does anyone know why there doesn't seem to be a 1.78 (16x9) DCP output on the latest version of DCP-o-Matic? The only version we can find with 1.78 as an output option is back at 2.11.30. We get a lot of films from colleges etc that send them in 1.78. Other than going back to the older version is there another option?
PC Windows 7 machines
Thanks,
Morgan

[Carsten]

All non strict DCI standard containers have been discarded on purpose. Use a flat container instead. 16:9 in flat container will display on screens exactly the same as in the previously available 16:9/1.77 container.

As one method to explain this, the preview window in versions up to 2.11x was content/source oriented. As DCI cinemas mostly only have presets for flat and scope, it would be deceiving to display the preview without letter- or pillarboxing that is inevitably taking place at the cinema.

So now, consider the preview display as the actual cinema screen.

This decision was made in part to make it easier for people to understand the difference between Scale To and Container Type - they used the same numbers/ratios and it was very confusing for users to understand why there are two settings with the same name for seemingly the same purpose.

The major reason however, is that if you interpret DCI/SMPTE specs strictly, other containers than flat/scope/full in 2k/4k are not allowed. Some projection systems even cause issues with them (garbled image, spurious decentering of playback, subtitles, etc.).

I understand it's irritating at first to experience an apparent loss of options/features in a new version, but it was done for good reasons.

- Carsten

[morganburkebeyers]

Perfect!

Thanks,
Morgan

[edula]

Hi there, Thanks for the comment on this. I thought I would follow up as I have a very specific reason for using the 16x9 container in some instances.

I often create DCPs for a local cinema which has a GDC SX-2001 server. This server has a mediablock that was designed before the existence of the AFR (alternate frame rate) addendum, and as such 25fps playback is not supported at full 2K resolution without some cropping of the image (usually quite noticeably down the right-hand side of the frame). As we often receive content in 25fps, especially many documentaries created in Europe, this was a frequent issue, especially during film festivals. I know of a few other cinemas here in Ireland with this same server that also have the exact same issue, and it was confirmed that this issue CANNOT be rectified with software updates for both the SX-2001 and SX-2001A (although all later models are fine).

I'd been looking to find a workaround, and discovered that content at 25fps in a 16x9 container would play out perfectly from the GDC SX-2001. It mentions in the SX-2001 manual that it can play 30fps in a 16x9 container, but although there is no mention of 25fps, it turns out that this is also the case and the image displays in full, with no cropping whatsoever, so is perfect for when I need to either create a new 25fps DCP or rewrap an existing one.

I can completely understand why this may have been removed from the container dropdown options, but unfortunately with this feature missing from the latest builds, it means I will have to roll back to an earlier version and miss out on any benefits of the updates. If there was any chance of having the oprion reinstated, it would really be a great help.

[Carsten]

I understand. Are you using Windows or Mac OS X?


As I do a lot of testing and create many DCPs for no other purpose than testing, I personally would prefer to have all imaginable options in a DCP creation tool. But I gave up on the idea to have them as standard features in DCP-o-matic. As an open-source DCP software, DCP-o-matic is often put down by 'professionals', and I think it is important for the reputation of DCP-o-matic to be as stable as possible and adhere to the standards.

I often thought that maybe it would be an option to enable certain features for DCP-o-matic, but don't make them accessible through the GUI, but only through the config file, so, by editing the config file, some people could re-enable these features, but they wouldn't be available to the 'general public'.
I guess, however, that this approach would only work for some features, not all. One of my first suggestions had been to keep non-standard containers, but emphasize on flat, scope, full in the list, so that would help people to choose only the preferred ones. Another option, as with non-standard frame rates, could have been to enable non-standard containers in advanced prefs. However, both methods would probably make it too easy to continue creating non-standard content.

Another issue that came up with discarding non-standard containers was that exporting to Prores/MP4 would also maintain letter-/pillarboxing for non-standard AR content. But that doesn't seem to cause much grief so far. I guess most people wanted the export function for native DCP content anyway, and these should be expected to be in either flat or scope. And for project screeners, subtitle tests, pillar/letterboxing is no big issue.

I don't know if Carl comes up with a solution, but so far, I guess I can only suggest to use an older version. I think 2.10.5 was the last stable to support custom containers. 2.11.21-2.11.33 should definitely be avoided, as it creates broken J2K, which causes issues on many servers.



- Carsten

[carl]

Hi,
I think the best idea here would be, as Carsten suggests, an option in "advanced" to enable non-standard containers. There's a clear reason why this is of benefit, and I think it would be well enough hidden that most people would not find it.

[Carsten]

Then maybe also add a hint/warning to the hints/warning window whenever non-standard containers are used? Do you think it's safe to re-introduce non-standard containers to the current code (scaling, cropping, export, subtitle positioning, centering, etc)?

I guess the hints/warnings thingy could get some polishing/updating anyway?

- Carsten

[carl]

A hint would be a good idea, yes. I fairly sure it's safe but I guess we'll find out if not! The code still knows about those other ratios since they can be selected for scaling content.

Any ideas for polishing the hints/warnings are welcome.

[carl]

OK the advanced option is in git so it will be in 2.13.37. Turns out there's already a hint for non-standard container ratios.

[edula]

Many thanks, all.

Si.