"-f bestaudio" downloads vorbis@128k when opus@160k is available

[timetimetimetime]

Checklist

• [?] I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2019.05.20
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar bug reports including closed ones
• I've read bugs section in FAQ

Verbose log

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', '-f', 'bestaudio', 'https://www.youtube.com/watch?v=SYRlTISvjww']
[debug] Encodings: locale cp1252, fs mbcs, out cp850, pref cp1252
[debug] youtube-dl version 2019.05.20
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.14393
[debug] exe versions: ffmpeg N-93886-gfbdb3aa179, ffprobe N-93886-gfbdb3aa179
[debug] Proxy map: {}
[youtube] SYRlTISvjww: Downloading webpage
[youtube] SYRlTISvjww: Downloading video info webpage
[youtube] {18} signature length 42.43, html5 player vflFo4HCs
[youtube] {137} signature length 42.43, html5 player vflFo4HCs
[youtube] {248} signature length 42.43, html5 player vflFo4HCs
[youtube] {136} signature length 42.43, html5 player vflFo4HCs
[youtube] {247} signature length 42.43, html5 player vflFo4HCs
[youtube] {135} signature length 42.43, html5 player vflFo4HCs
[youtube] {244} signature length 42.43, html5 player vflFo4HCs
[youtube] {134} signature length 42.43, html5 player vflFo4HCs
[youtube] {243} signature length 42.43, html5 player vflFo4HCs
[youtube] {133} signature length 42.41, html5 player vflFo4HCs
[youtube] SYRlTISvjww: Downloading player https://www.youtube.com/yts/jsbin/player_ias-vflFo4HCs/en_US/base.js
[youtube] {242} signature length 42.43, html5 player vflFo4HCs
[youtube] {160} signature length 42.43, html5 player vflFo4HCs
[youtube] {278} signature length 42.43, html5 player vflFo4HCs
[youtube] {140} signature length 42.43, html5 player vflFo4HCs
[youtube] {171} signature length 42.43, html5 player vflFo4HCs
[youtube] {249} signature length 42.43, html5 player vflFo4HCs
[youtube] {250} signature length 42.43, html5 player vflFo4HCs
[youtube] {251} signature length 42.43, html5 player vflFo4HCs
[debug] Invoking downloader on 'https://r1---sn-q4flrnel.googlevideo.com/videoplayback?id=o-AAIF4FuzADn9H4vWDxwV9HGBRhe5geYWHGR7dGWXKhFr&itag=171&source=youtube&requiressl=yes&mm=31%2C26&mn=sn-q4flrnel%2Csn-5ualdn7r&ms=au%2Conr&mv=m&pl=42&ei=bVfjXJvCJIK5iwTtk5DQCQ&initcwndbps=1067500&mime=audio%2Fwebm&gir=yes&clen=4360584&dur=268.664&lmt=1540151762175749&mt=1558402850&fvip=1&keepalive=yes&c=WEB&txp=5411222&ip=2600%3A1702%3A1dc1%3A82c0%3Abdec%3Abfd5%3A7401%3Abcd7&ipbits=0&expire=1558424525&sparams=ip%2Cipbits%2Cexpire%2Cid%2Citag%2Csource%2Crequiressl%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Cei%2Cinitcwndbps%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&key=yt8&signature=52D61277C3DD65915C42BE72196FB4E03F5A7F38.7C169560EE684A2817F95681C5FB2A04D505829C&ratebypass=yes'
[download] Destination: Uptime Funk - (Uptown Funk parody)-SYRlTISvjww.webm
[download] 100% of 4.16MiB in 00:06

Description

I am trying to download https://www.youtube.com/watch?v=SYRlTISvjww with -f bestaudio. However, this downloads the inferior vorbis@128k track even though an opus&160k track is available, as evidenced by -F https://www.youtube.com/watch?v=SYRlTISvjww

[dstftw]

Actual reported bitrate per metadata of 171 is higher that 251.