Singler line FFMPEG cmd to Merge Video /Audio and retain both audios

Question

I have a project that requires merging of a video file with another audio file. The expected out put is an video file that will have both the audio from actual video and the me

Answer 1

This is very easy with FFmpeg:

ffmpeg -i vid.mp4 -i audio.mp3 -codec:a libmp3lame -ar 44100 -ab 64k -ac 1 -q:v 1 -pix_fmt yuv420p -map 0:0 -map 1:0