I want to remux a mkv file into mp4. I used the following command.

ffmpeg -i "input.mkv" -c:v copy -c:a copy -map 0:0 -map 0:1 -map 0:2 -map 0:3 -c:s mov_text "output.mp4"

Problem: The subtitles in the output.mp4 file are way too small.

Also, the subtitles of the mp4 file are unaffected when I try to make them bigger from vlc preferences. I can turn them on/off but I think they are somewhat hardcoded. I had to rencode subtitles while remuxing as otherwise it was showing error. Also, I'm using the latest version of mmpeg.

input.mkv :

output.mp4 :

input.mkv has the following streams,codecs :

I searched a lot, but couldn't find a way to make mov_text subtitles bigger. How can I make them bigger?

Or Please suggest any other way to retain the subtitles while remuxing from mkv to mp4.

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Utkarsh Singh is a new contributor to this site. Take care in asking for clarification, commenting, and answering. Check out our Code of Conduct.

I consider subtitle text rendering is part of the player feature. If you are using VLC, may this link, https://wiki.videolan.org/VLC_HowTo/Adjust_subtitle_font_settings/, help?

I had tried on a mkv to mp4 video, before enter image description here

After, I changed the VLC subtitle font size to larger, exited the program and replayed it again, i got enter image description here

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  • I already tried to change font size, appearance from vlc preferences, as I mentioned in the post. But it did not have any affect on the subtitiles. – Utkarsh Singh 2 days ago
  • i updated my answer with screen-capture – xer-rex yesterday
  • Every other text becomes large except the subtitles.ScreenShot , Also you can notice that the subtitles are not hardcoded. Still their size is unaffected by changes in vlc preferences. – Utkarsh Singh 7 hours ago

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