Basic and CURRRENT (2015) loading of M2TS files

Could someone please tell me what is the CURRENT (in Mar. 2015) best way to open a straight-forward HD video file (M2TS), 1080i, AVC (H.264) video codec? Mine are captured from a Hauppauge capture device. I've tried DirectShowSource, but I can't scrub frame-to-frame quickly in order to plan edits, etc. I do have an i5 w/4 cores, but DirectShowSource is too slow to be useful, at least for planning edits. I'm trying to avoid converting it to a huge AVI and instead directly open it in AviSynth.

3 good options: 1. DGDecNV 2. LWLibavVideoSource 3. FFVideoSource Don't ask what's best (rule #12).

@TCmullet You can try to mux to mkv using gdsmux or dsmux, mkvmerge might use timestamps and loose sync when you cut. That's the default in StaxRip which has rich cutting support. DGDecNV handles TS directly quite well. @Groucho2004 2 and 3 can be a complete failure with many TS files I would say, especially when you try to seek and cut.