I have a file that contains subtitles in vobsub format and im trying to encode it using ffmpeg. Is there a way to encode it in mp4? When I use c:s copy the subtitles become way larger than their original size. The file contains, different audios, subtitles and chapters.

The code I used is:
ffmpeg -i input.mp4 -map 0 -map -0:12 -c:v hevc_nvenc -preset fast -c:a copy -c:s copy “output.mp4”

Where -map -0:12 is because for some reason stream 12 causes an error, and -c:v hevc_nvenc because I’m trying to find a code that works first and then encode using H.265.

When i encode the output in mkv it seems to work, but in mp4 it cause the mentioned problem about the large subtitles.