the movie's timeline sucks 16 seconds ahead, please fix it

Subtitles files can't be in sync with all the different copies of a movie.
That's why video players have an option to add a delay (see "Tools > Track Synchronization" in VLC).
If you want to make that change permanent, you can use a software (Aegisub, SubtitleEdit, ...) or an online tools ( https://subtitletools.com/subtitle-sync-shifter but there are a lot more )

the problem with the film is that the first 49 seconds are not present, and the subtitle starts from 04 seconds, i.e. the first 49 seconds are lost

Don't worry, video players support negative timestamps :)

I don't think you understand the problem subtitle starts in 04 seconds speech 49 seconds, so 45 seconds between Dec.

So the easiest way is to go here: https://subtitletools.com/subtitle-sync-shifter
Upload the SRT file, then type "45000" and click "Shift". A fixed SRT file will be downloaded.