[FFmpeg-user] Help with creating MP4 video with multiple audio tracks

[Chiara]

Hello,

I’m new to this, so I apologize if I’m missing something trivial. I need to create an .mp4 video output with multiple audio tracks in it. I run the command:

ffmpeg -i sample-mp4-file.mp4 -i hindi.aac -i tamil.aac -i telugu.aac -map 1 -map 2 -map 3 -metadata:s:a:0 language=eng -metadata:s:a:1 language=tam -metadata:s:a:2 language=tel -metadata:s:a:3 language=hin -codec copy multilanguage.mp4

However, the output includes only the multiple audio tracks with no video (0 kB) – see my  output results <https://i.stack.imgur.com/ejXrL.png>.

What am I doing wrong? Why am I always getting export missing the video? So far, I tried various .mp4 video files, and also MP3 format for audio tracks.

Any kind of help would be much appreciated.

Thank you.

Best regards,

Chiara