Combining an Audio-only and Video-only MP4 with
ffmpeg on the command-line
This post's featured URL for sharing metadata is https://www.jvt.me/img/profile.jpg.
Last night, I was downloading videos from Facebook, and found that they're sending their audio and video streams as separate, chunked responses.
I wanted to combine these, which fortunately is pretty trivial to do so using
ffmpeg, thanks to a hint from this thread on SuperUser:
ffmpeg -i video.mp4 -i audio.mp4 -c copy out.mp4
See the thread above for other cases, such as when you want to reencode the audio, or replace the existing audio stream.