[r0lZ]

Sorry to reply only now. This morning, I was blind, without internet!

I haven't noticed the PTS differences yet, but anyway, I use the same program (tsMuxeR) to demux the subtitles from the M2TS of the BD and from the 3D MKV, so I suppose it's not tsMuxeR's fault, and BD3D2MK3D is not responsible. I suppose the little differences are introduced by MakeMKV, perhaps because at some point, the PTS are converted to frame number, and then back to PTS? Anyway, when BDSup2Sub converts the subtitles, similar rounding problems happen. As long as the difference is less than one video frame, I don't care.

I know also that BDSup2Sub is totally wrong when it converts the SUP to XML/PNG. IIRC, the XML contains always the timings for 24 fps, regardless of the options you use during the conversion and the frame rate written in the XML. When the XML/PNG stream is converted back to SUP (or DVD SUB), it is necessary to specify that the frame rate must be converted from 23.976 to 23.976, or the timings are completely wrong. That conversions can introduce rounding problems, and finally a difference of one video frame, but IMO, for the subtitles, that doesn't matter much.

I will verify this when I'll have some time to do new tests, with long movies. But that may take some times. I'm currently working on the second demux pass for the TrueHD tracks...