Hey there I'm trying to hardcode subtitles onto an mp4 movie file using shutter encoder which I have done numerous times before without issue. The srt file syncs and plays perfectly with the mp4 movie file using vlc player, but when I try to hardcode the subs using shutter encoder with either mpeg2 or h264 as the output codec I get the following error message:

" [AVFilterGraph @ 0000025e06627800] Error processing filtergraph: Invalid data found when processing input
[in#1 @ 0000025e04fbecc0] Error opening input: Invalid data found when processing input
Error opening input files: Invalid data found when processing input"

I've managed to hardcode other srt files into the same mp4 movie file using shutter encoder but unfortunately the subtitles are slightly out of synch with the film so obviously I'd prefer to harcode the perfectly synched srt. If anyone can help me out here I'd really appreciate it? Thanks