====== ffmpeg - Subtitles - Add multiple subtitles ======
===== Add both SRT subtitles =====
ffmpeg -i input.mp4 -i subtitle.en.srt -i subtitle.chi.srt -map 0 -map 1 -map 2 -c copy -c:s mov_text -metadata:s:s:0 language=eng -metadata:s:s:1 language=chi output_eng_chi.mp4
**NOTE:** This adds two
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===== Add another SRT subtitle =====
This assumes that the input file already has a subtitle.
ffmpeg -i input_english.mp4 -i subtitle.chi.srt -map 0 -map 1 -c copy -c:s mov_text -metadata:s:s:1 language=chi output_chi.mp4
**NOTE:**
* **-map 0** refers to the video, input_english.mp4, which already contains existing english subtitles.
* **-map 1** refers to the subtitle file, subtitle.chi.srt, to add a different subtitle to the output.
Without **-map**, ffmpeg will select only one subtitle stream among all inputs.