[DCP-o-matic] DCP file size:

Hi Carl, hope all is well with you, I'm a user of your product DCP-o-matic for two years now and I have to say that it's a very good DCP creator and one of the best according to the reviews I've seen online. I use it to create movie trailers for our cinema here in Barbados. Though I usually receive links from our movie Distributors to download their DCP trailer content for our screens, if there are any unavailable content I will go to HDtrailers.net or Thedigitaltheater.com. and download the the content if available. These trailers which I download from the two sites in the above have to be prepped for DCP export which I use the DCP-o-matic DCP creator to finish the trailer. DCP file size: ( Distributors content file size vs DCP-o-matic file size.) My observation of file size that the trailer content downloaded via link from our Distributors have a greater file size than any trailer content that I create using the DCP-o-matic creator. I understand that the Distributor's content are mastered in Dolby 5.1 and mixed in a facility studio with 5.1 audio track stems and full 2k video content that is then exported to DCP with very expensive DCP creator software like Easy DCP and Wraptor DCP. but the trailer content download from Thedigitaltheater.com that are mastered in Dolby 5.1 are copies from the good content and then converted to MKV and MP4 files that are smaller in size because of the compression of audio and video bit rates. If I convert one of these compressed trailer files to DCP using The DCP-o-matic creator, then compare it to one of the Distributors files (the exact trailer) there is always a difference in the size of the output file. Mastering in Adobe Premiere Pro and Audition: I've experimented with creating 2048x858 2K & 1998x1080 2K QuickTime video files in Premiere with maximum bit rates and bit depths for optimum picture quality, and have extracting the 5.1 files from the compressed content with Audition then export to 5.1 wav files. Then I create and export a 5.1 2k sequence file that give me a 2.9gb or a 3.0gb file depending on the length of the trailer. DCP-o-matic export: After I have imported the sequence file that I have created in Premiere into DCP-o-matic and make all the necessary adjustments then I make the DCP. After the DCP is finished, I am seeing that the file existing in the content folder is half the size of the sequence file. Example! [ imported sequence file = 3.0gb] [exported DCP folder with ASSETMAP, cpl, j2c, pcm, pkl, VOLINDEX = 1.5gb.] There is also a drop in resolutions in the exhibition of the trailer content although all DCP contents are 2K. (1) Is the compression rate set by default to 2gb alone for all contents that are approximately 2 minutes 30 seconds? (2) Or, is there something that I can do to maintain a maximum quality content and keep my file size matching the imported file size? Thanks! Best regards, Clive.