5.1 sound is working in 4k video downloader

[ValZapod]

Checklist

• [x ] I'm reporting a feature request
• [x ] I've verified that I'm running youtube-dl version 2019.11.28
• [x ] I've searched the bugtracker for similar feature requests including closed ones

Description

WRITE DESCRIPTION HERE
https://www.youtube.com/watch?v=iTHtXgnhqfM
is using 5.1 sound (verified with mediainfo, downloaded with 4k video downloader)
Conversation on avsforum https://www.avsforum.com/forum/40-oled-technology-flat-panels-general/3057634-2019-c9a-e9-owner-s-thread-no-price-talk-340.html#post58914328
File downloaded from youtube with 4k video downloader:
Dolby Atmos 5.1 Surround Sound Test.zip

I see that issue #12004 which is WRONG!

[dstftw]

Post the full verbose output.

[ValZapod]

@dstftw What do you want from me?

[ValZapod]

@dstftw Okay. I understand, there is already 5.1 sound in -f 258. You could have just said that.
258 m4a audio only tiny 389k , m4a_dash container, mp4a.40.2 (48000Hz), 2.94MiB

[ValZapod]

Just a note, you can use pot player to have 5.1 sound! Nice!