How to get audio when watching partially downloaded file

[student-sx]

• I'm asking a question
• I've looked through the README and FAQ for similar questions
• I've searched the bugtracker for similar questions including closed ones

Question

If I download a video using youtube-dl I often want to watch the video already before the download finished. However if I just play the *.part file, there is no audio.

So how should I initiate the download process such that the partial downloaded file also contains the correct audio stream?

If I already initiated a download "the wrong way", i.e. such that the part file doesn't contain audio, is there a way to fix this while the download continues?

[pukkandan]

youtube-dl by default downloads the best video and best audio separately and merges them. There are a few workarounds to your issue though:

1. Use -f best. This restricts the download to formats containing both video and audio inside. For youtube, it is only 720p and 360p.
   OR
2. If your player supports "external audio", you can download the audio separately using -f bestaudio and load it as external audio in the player

[student-sx]

Thanks, that helps!

For future readers I may add that if you use mpv, then the second method works via something like

mpv video.mp4 --audio-file=audio.m4a