Depending on the the aspect ratio and resolution of your film you will producing a DCP from a master with one of the following resolutions.
2K DCI Flat. 1998 x 1080. 1.85
2K DCI Scope. 2048 x 858. 2.39
4K DCI Flat. 3996 x 2160. 1.85
4K DCI Scope. 4096 x 1716. 2.39
and either stereo or 5.1 sound.
See the Exporting section for information on how to export your 'Universal Master'
Open DCP-o-matic
Select File>New and save to your project drive
In DCP-o-matic>Content add your RGB 4444 12bit QuickTime and any separate audio files.. After the clip has been processed use the following settings.
Audio Settings Stereo
Audio Settings 5.1. For an easy life us a 'interleaved file'.
You will need to trim the clock off your clip - 28 seconds will work so there will be 2 seconds of black before first frame.
In DCP-o-matic>Content use the following setting
Check your DCP for aspect ratio
Finally make your DCP - take a break it will take some time