jdryyz said: Just FYI, the rate I came up with was 20Mbps.

That's sounds about right, depending on the size of the audio and subtitle tracks you wish to retain, but consider using MeGUI's built-in bitrate calculator to find a more precise figure. You could also try recompressing with a CRF of 16. That should retain the quality of the original, and at 720p the result should easily fit on a BD-25.

I find it strange that an Oppo player has trouble with the file though. Are you sure that a re-encode is necessary?