You can play back DCPs with Stereoscopic player and jpeg2000 decoder
These can be used to check the DCP for some common problems or to screen the DCP. You could use the trial version of Easydcp Player (It plays only the first 15 seconds of a DCP) to check if the DCP loads correctly, the colors are OK and even do a file hash check. With stereoscopic player you can check for audio sync and see if the colors seem OK (The trial version plays DCPs for 5 minutes at a time).
Only Easydcp player can play :
-DCPs with offsets on audio and video,
-DCPs with interop/SMPTE subtitles,
-DCPs that need customs 3D LUTs
Easydcp player also support SMPTE DCPs and can export DCPs to Prores Quicktime files with P3, rec709 or custom color/gamma encoding.
-These players can only use 8/10 bit color, not 12 bit.
-They need fast computers, Both can play DCPs on a i7 quad core CPU PC.
-Your DCP will look and sound different in a movie theatre than on your typical PC.
Easydcp player with a Blackmagic HD-SDI device could be used to play DCPs originating from 8 bit HDCAM/10 bit HDCAM SR since the source is 8/10 bit. For smaller venues at film festivals without digital cinema equipment this could be an alternative to HDCAM player rental. It could also be used to play 25 and 30 fps SMPTE DCPs made from video sources in cinemas that has digital cinema servers that do not support these. The money a festival saves on HDCAM player rental for some years could pay for a non profit license bundle of easydcp creator and easydcp player and computers. When transferring HDCAM to DCP you could replace the stereo mix with a 5.1 mix. Or add subtitles.
But there is the added logistics of asking for permission to transfer each movie, and if the transfer is done incorrectly you could loose quality.