How to make 25 FPS SMPTE DCPs with Interop subtitles
Easydcp player now support SMPTE MXF subtitles. Easydcp player can play 25,30 FPS films transferred from HDCAM or other sources with both MXF and interop subtitles and 5.1 sound. You can get a module for Easydcp Creator to make 25 FPS SMPTE DCPs with Interop subtitles. You can also use the burn in subtitles option in Easydcp Creator to avoid making them.
Interop subtitles was supposed to be exchanged with mxf subtitles, but SMPTE DCPs with Interop subtitles seems to be compatible with more servers than SMPTE DCPs with MXF subtitles.
Doremi has supported 25 FPS DCPs with Interop subtitles in their mastering software and server, this may be the reason these DCPs are playable on servers.
Doremi supports SMPTE MXF subtitles on their servers when you use the Doremi’s internal subtitle engine, but not all servers do.
This is how I made a 25 FPS SMPTE DCP with interop subtitles with Easydcp Creator and Openssl (Windows).
I used Michael Cinquin example 25 FPS SMPTE DCP with interop subtitles as a guide. He uses a extra font file in the root of the DCP but that was not necessary to play the DCP in Easydcp player. I have only tested this DCP in Easydcp player and on a Doremi server.
-I made a 25 SMPTE DCP without subtitles in easydcp creator.
-I also had a 24 interop DCP of the same DCP without subtitles.
-I opened the 24 DCP in easydcp creator and made a supplemental package (I marked the MXF assets as references) with the 25 DCP Interop XML subtitle file added to the reel(s).
You could use any 24 FPS DCP to make the supplemental package.
-When making different versions of a DCP it is common to make supplemental packages that only adds the subtitles.
-I opened the Assetmap, CPL and PKL from the 24 fps supplemental package and the 25 SMPTE DCP in a text editor (notepad ++).
-I took the subtitle asset and the font asset from the 24 Assetmap and pasted it in the 25 Assetmap and edited it to match how the 25 SMPTE Assetmap looked. You can find the length in the pkl file, but you can also find it with right clicking on the file and choosing properties (size).
-I copied the main subtitle part(s) from the 24 cpl to the 25 cpl and changed the edit rate to “25 1” and matched the duration with the sound and picture.
I changed the titles of the 25 DCP so it was marked as having subtitles in the CPL. http://digitalcinemanamingconvention.com/
-I then saved the CPL, PKL and Assetmap from the 25 DCP to a new folder. I also copied the font directory from the supplemental package to this folder. And the VOLINDEX file from the 25 DCP directory.
-I changed the size of the CPL file in Assetmap to it’s new size
-I changed the size value of the CPL file in the PKL
-I changed the titles of the 25 DCP so it was marked as having subtitles in the PKL.
-I copied the subtitle font and XML entries from the 24 PKL to the 25 PKL.
-I changed the Type for the subtitle XML to text/xml in the 25 PKL
-I installed cygwin with openssl, went to the DCP folder in the cygwin shell and used this command from the Wikipedia DCP page
openssl sha1 -binary "FILE_NAME" | openssl base64 on the cpl file and got the new hash value for the CPL file which I then entered as the new hash value for the CPL file in the PKL file.
-Then I copied the MXF files from the original 25 DCP folder to the new one and opened it in Easydcp player. Easydcp player checks if the sizes match when you open the DCP, and can check the File hashes when you have opened the DCP.