Best audio isn’t chosen by default

[deterenkelt]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2020.06.06
• 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

PASTE VERBOSE LOG HERE
[debug] System config: []
[debug] User config: ['--no-mtime']
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://youtu.be/1G6uFsf5l-k']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2020.06.06
[debug] Python version 3.6.10 (CPython) - Linux-4.17.0-gentoo-i5-x86_64-Intel-R-_Core-TM-_i5-2500K_CPU_@_3.30GHz-with-gentoo-2.6
[debug] exe versions: ffmpeg N-95335-ga7fd127970, ffprobe N-95335-ga7fd127970, rtmpdump 2.4
[debug] Proxy map: {}
[youtube] 1G6uFsf5l-k: Downloading webpage
[youtube] 1G6uFsf5l-k: Downloading MPD manifest
[debug] Default format spec: bestvideo+bestaudio/best
WARNING: Requested formats are incompatible for merge and will be merged into mkv.
[debug] Invoking downloader on 'https://manifest.googlevideo.com/api/manifest/dash/expire/1591792688/ei/0H_gXuCTA8-ayAX0waDwAQ/ip/77.243.108.114/id/d46eae16c7f997e9/source/youtube/requiressl/yes/playback_host/r2---sn-nu5gapo3-n8ve.googlevideo.com/mh/m-/mm/31%2C29/mn/sn-nu5gapo3-n8ve%2Csn-n8v7znly/ms/au%2Crdu/mv/m/mvi/1/pl/21/tx/23903764/txs/23903758%2C23903759%2C23903760%2C23903761%2C23903762%2C23903763%2C23903764%2C23903765%2C23903766/hfr/all/as/fmp4_audio_clear%2Cwebm_audio_clear%2Cwebm2_audio_clear%2Cfmp4_sd_hd_clear%2Cwebm2_sd_hd_clear/initcwndbps/1372500/vprv/1/mt/1591770993/fvip/17/keepalive/yes/fexp/23882514/itag/0/sparams/expire%2Cei%2Cip%2Cid%2Csource%2Crequiressl%2Ctx%2Ctxs%2Chfr%2Cas%2Cvprv%2Citag/sig/AOq0QJ8wRQIgbx-NxahFGstfjBAYn_Jb9rzgBWXte1TnsVlXf8j3k_sCIQCztGs1kAakwMWmFhTr-3jWnWFGjbs2n9HWuUJw6ZjFpQ%3D%3D/lsparams/playback_host%2Cmh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps/lsig/AG3C_xAwRQIhANo0kSFj8XiAAFrD6gRcrzL83ZQnOfEEnCJMRn0g0FRZAiBzGIw5D_PCbEaMuRKLB0dTrWrnsqk55l7_s1TVmUEDQw%3D%3D'
[dashsegments] Total fragments: 3
[download] Destination: [Arknights]When doktah woke up-1G6uFsf5l-k.f248.webm
[download] 100% of 607.91KiB in 00:00
[debug] Invoking downloader on 'https://manifest.googlevideo.com/api/manifest/dash/expire/1591792688/ei/0H_gXuCTA8-ayAX0waDwAQ/ip/77.243.108.114/id/d46eae16c7f997e9/source/youtube/requiressl/yes/playback_host/r2---sn-nu5gapo3-n8ve.googlevideo.com/mh/m-/mm/31%2C29/mn/sn-nu5gapo3-n8ve%2Csn-n8v7znly/ms/au%2Crdu/mv/m/mvi/1/pl/21/tx/23903764/txs/23903758%2C23903759%2C23903760%2C23903761%2C23903762%2C23903763%2C23903764%2C23903765%2C23903766/hfr/all/as/fmp4_audio_clear%2Cwebm_audio_clear%2Cwebm2_audio_clear%2Cfmp4_sd_hd_clear%2Cwebm2_sd_hd_clear/initcwndbps/1372500/vprv/1/mt/1591770993/fvip/17/keepalive/yes/fexp/23882514/itag/0/sparams/expire%2Cei%2Cip%2Cid%2Csource%2Crequiressl%2Ctx%2Ctxs%2Chfr%2Cas%2Cvprv%2Citag/sig/AOq0QJ8wRQIgbx-NxahFGstfjBAYn_Jb9rzgBWXte1TnsVlXf8j3k_sCIQCztGs1kAakwMWmFhTr-3jWnWFGjbs2n9HWuUJw6ZjFpQ%3D%3D/lsparams/playback_host%2Cmh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps/lsig/AG3C_xAwRQIhANo0kSFj8XiAAFrD6gRcrzL83ZQnOfEEnCJMRn0g0FRZAiBzGIw5D_PCbEaMuRKLB0dTrWrnsqk55l7_s1TVmUEDQw%3D%3D'
[dashsegments] Total fragments: 2
[download] Destination: [Arknights]When doktah woke up-1G6uFsf5l-k.f140.m4a
[download] 100% of 146.50KiB in 00:00
[ffmpeg] Merging formats into "[Arknights]When doktah woke up-1G6uFsf5l-k.mkv"
[debug] ffmpeg command line: ffmpeg -y -loglevel repeat+info -i 'file:[Arknights]When doktah woke up-1G6uFsf5l-k.f248.webm' -i 'file:[Arknights]When doktah woke up-1G6uFsf5l-k.f140.m4a' -c copy -map 0:v:0 -map 1:a:0 'file:[Arknights]When doktah woke up-1G6uFsf5l-k.temp.mkv'
Deleting original file [Arknights]When doktah woke up-1G6uFsf5l-k.f248.webm (pass -k to keep)
Deleting original file [Arknights]When doktah woke up-1G6uFsf5l-k.f140.m4a (pass -k to keep)

Description

WRITE DESCRIPTION HERE

Best audio format for the video is no. 251, as obviously Opus @160 kbps is better than AAC @128 kbps. Yet youtube-dl downloads format no. 140

[youtube] 1G6uFsf5l-k: Downloading webpage
WARNING: video doesn't have subtitles
[youtube] 1G6uFsf5l-k: Downloading MPD manifest
[info] Available formats for 1G6uFsf5l-k:
format code  extension  resolution note
139          m4a        audio only DASH audio   49k , m4a_dash container, mp4a.40.5@ 48k (22050Hz)
251          webm       audio only DASH audio  119k , webm_dash container, opus @160k (48000Hz)
140          m4a        audio only DASH audio  130k , m4a_dash container, mp4a.40.2@128k (44100Hz)
278          webm       256x144    DASH video   95k , webm_dash container, vp9, 30fps, video only
160          mp4        256x144    DASH video  108k , mp4_dash container, avc1.4d400b, 30fps, video only
134          mp4        640x360    DASH video  192k , mp4_dash container, avc1.4d401e, 30fps, video only
242          webm       426x240    DASH video  220k , webm_dash container, vp9, 30fps, video only
133          mp4        426x240    DASH video  242k , mp4_dash container, avc1.4d400c, 30fps, video only
243          webm       640x360    DASH video  405k , webm_dash container, vp9, 30fps, video only
244          webm       854x480    DASH video  752k , webm_dash container, vp9, 30fps, video only
135          mp4        854x480    DASH video 1155k , mp4_dash container, avc1.4d4014, 30fps, video only
247          webm       1280x720   DASH video 1505k , webm_dash container, vp9, 30fps, video only
137          mp4        1920x1080  DASH video 1910k , mp4_dash container, avc1.640028, 30fps, video only
136          mp4        1280x720   DASH video 2310k , mp4_dash container, avc1.4d4016, 30fps, video only
248          webm       1920x1080  DASH video 2646k , webm_dash container, vp9, 30fps, video only
18           mp4        640x360    360p  241k , avc1.42001E, 30fps, mp4a.40.2@ 96k (44100Hz), 266.25KiB
22           mp4        1280x720   720p 1361k , avc1.64001F, 30fps, mp4a.40.2@192k (44100Hz) (best)

[dstftw]

Reported bitrate for 140 is higher that 251.