The question was about avi + srt. I never tried to input video_ts. According to the web site, you can.
input formats: MPEG-1, MPEG-2, MPEG-4, DIVX, XviD, non-encrypted VOB and VIDEO_TS, Quicktime .MOV, .DV, .WAV, Real Audio, Real Video, H.263, MP4 H.264, PGM, YUV, PPM, AC3, PCM8/16 bits...