I converted one large WMV to MPEG stream with TMPGEnc Plus. As it was choking and freezing on me, I splitted the output file in two parts.

Now for chaptering and authoring, I'd like to join the mpegs outputted by TMPGENC so I have ONE video and ONE audio file.

Which program is suitable for joining mpeg2 (m2v and mp2?)

Also, dumb question, does muxing-demuxing impact the quality or is it a 100% lossless process?

thank you in advance!