How can i mix mutilple audio streams with a video having embedded audio? Eg i am having video.mp4 which has embedded audio stream. I want to mix one or more audio streams with it,keeping the orignal embedded audio stream. How can i do it? Thanks.
Basic template is
ffmpeg -i video.mp4 -i audio1.mp3 -i audio2.mp3 -filter_complex "[0][1][2]amix=3[a]" -map 0:v -map "[a]" -c:v copy out.mp4