I am trying to use
ffmpeg to make two videos play next to each other simultaneously with both videos' audio combined. This is the command I'm currently running:
$ ffmpeg -i video0.mp4 -i video1.mp4 \ -filter_complex "[0:v][1:v]vstack[video]; [0:a][1:a]amix=inputs=2[audio]" \ -map "[video]" -map "[audio]" -ac 2 output.mp4
When I run this command though, I get the following error:
Stream specifier ':a' in filtergraph description [0:v][1:v]vstack[video]; [0:a][1:a]amix=inputs=2[audio] matches no streams.
It seems like
:a does not refer to the audio stream. What is the proper way to specify the audio streams of my input videos as input streams for the amix filter?