====== ffmpeg - Audio - Add more audio tracks to a video ======

<code bash>
ffmpeg -i input.mp4 -i audio.mp3 -map 0 -map 1 -c copy output.mp4
</code>

<WRAP info>
**NOTE:**  Using the **-map** flag means that you can specify which streams to keep.

  * **-map 0** is input.mp4.
  * **-map 1** is audio.mp3.

  * The streams of both inputs are copied together as **-c copy** means no re-encoding is done.

</WRAP>