Problem with SSA/ASS hard subs

[Eva-Unit01]

I am trying to save an AVI file with SSA/ASS hard subs. I extracted the original AVI file, the needed audio track and the formatted ASS subtitle track using MKVExtracGUI.

I opened up the AVI, added the ac3 audio track and added the SSA subs as hard subs as a filter in avidemux and then saved the video as an avi.

The problem was, when I watched the AVI file in mpc, the subtitles looked like this instead of just displaying subtitles at the top and bottom it added a cluster of french and japanese subs that never appear in the source MKV I extracted the video and sub from. I suspect the problem may be with vobsub.