YouTube - Dash Video download contains artifacts/glitches

[ghost]

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2020.02.16
• 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

youtube-dl --list-formats -v --proxy "XXX" https://www.youtube.com/watch?v=oGMuZiG6JUc
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'--list-formats', u'-v', u'--proxy', u'XXX', u'https://www.youtube.com/watch?v=oGMuZiG6JUc']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2020.02.16
[debug] Python version 2.7.9 (CPython) - Linux-3.16.0-4-amd64-x86_64-with-debian-8.11
[debug] exe versions: ffmpeg 3.2.4, ffprobe 3.2.4
[debug] Proxy map: {u'http': u'XXX', u'https': u'XXX'}
[youtube] oGMuZiG6JUc: Downloading webpage
[youtube] oGMuZiG6JUc: Downloading video info webpage
[youtube] oGMuZiG6JUc: Downloading MPD manifest
[info] Available formats for oGMuZiG6JUc:
format code  extension  resolution note
139          m4a        audio only DASH audio   49k , m4a_dash container, mp4a.40.5@ 48k (22050Hz)
140          m4a        audio only DASH audio  130k , m4a_dash container, mp4a.40.2@128k (44100Hz)
251          webm       audio only DASH audio  134k , webm_dash container, opus @160k (48000Hz)
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
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
134          mp4        640x360    DASH video  633k , mp4_dash container, avc1.4d401e, 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
136          mp4        1280x720   DASH video 2310k , mp4_dash container, avc1.4d4016, 30fps, video only
302          webm       1280x720   DASH video 2646k , webm_dash container, vp9, 60fps, video only
248          webm       1920x1080  DASH video 2646k , webm_dash container, vp9, 30fps, video only
298          mp4        1280x720   DASH video 3465k , mp4_dash container, avc1.4d4016, 60fps, video only
137          mp4        1920x1080  DASH video 4331k , mp4_dash container, avc1.64001e, 30fps, video only
303          webm       1920x1080  DASH video 4410k , webm_dash container, vp9, 60fps, video only
299          mp4        1920x1080  DASH video 5775k , mp4_dash container, avc1.64001e, 60fps, video only
18           mp4        640x360    360p  631k , avc1.42001E, mp4a.40.2@ 96k (44100Hz), 5.87MiB
22           mp4        1280x720   720p 1911k , avc1.64001F, mp4a.40.2@192k (44100Hz) (best)

youtube-dl -v --prefer-ffmpeg --ffmpeg-location /usr/local/bin/ffmpeg -f 136+140 --merge-output-format mp4 --proxy "XXX" https://www.youtube.com/watch?v=oGMuZiG6JUc
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'--prefer-ffmpeg', u'--ffmpeg-location', u'/usr/local/bin/ffmpeg', u'-f', u'136+140', u'--merge-output-format', u'mp4', u'--proxy', u'XXX', u'https://www.youtube.com/watch?v=oGMuZiG6JUc']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2020.02.16
[debug] Python version 2.7.9 (CPython) - Linux-3.16.0-4-amd64-x86_64-with-debian-8.11
[debug] exe versions: ffmpeg 3.2.4, ffprobe 3.2.4
[debug] Proxy map: {u'http': u'XXX', u'https': u'XXX'}
[youtube] oGMuZiG6JUc: Downloading webpage
[youtube] oGMuZiG6JUc: Downloading video info webpage
[youtube] oGMuZiG6JUc: Downloading MPD manifest
[debug] Invoking downloader on u'https://manifest.googlevideo.com/api/manifest/dash/expire/1581969073/ei/UZpKXqjOGo25gAe51Z2gCg/ip/88.204.45.85/id/a0632e6621ba2547/source/youtube/requiressl/yes/playback_host/r1---sn-nvm-cxbz.googlevideo.com/mm/31%2C29/mn/sn-nvm-cxbz%2Csn-4g5e6ns6/ms/au%2Crdu/mv/m/mvi/0/pl/21/tx/23791272/txs/23791272%2C23791946/hfr/all/as/fmp4_audio_clear%2Cwebm_audio_clear%2Cwebm2_audio_clear%2Cfmp4_sd_hd_clear%2Cwebm2_sd_hd_clear/initcwndbps/1011250/vprv/1/mt/1581947403/fvip/1/keepalive/yes/fexp/23842630/itag/0/sparams/expire%2Cei%2Cip%2Cid%2Csource%2Crequiressl%2Ctx%2Ctxs%2Chfr%2Cas%2Cvprv%2Citag/sig/ALgxI2wwRgIhAPW33gBgjTnJZRN3NHldZNRij3VBrasQ9WF7LICVXE5QAiEAv3FTUbTAWfhE0fPPVK8C-OcuhMeBzrts978H3Ekps4I%3D/lsparams/playback_host%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps/lsig/AHylml4wRQIgEJkWbVfsy1ESZtKyAr9MvpRgc-8P2dxDrOJbmSiEFFkCIQDsybTcSccQLNkjA-ftkTJcgtLnAOchiUTT0knBmJiyrQ%3D%3D'
[dashsegments] Total fragments: 16
[download] Destination: Lethal Running Beta Footage-oGMuZiG6JUc.f136.mp4
[download] 100% of 19.06MiB in 00:08
[debug] Invoking downloader on u'https://manifest.googlevideo.com/api/manifest/dash/expire/1581969073/ei/UZpKXqjOGo25gAe51Z2gCg/ip/88.204.45.85/id/a0632e6621ba2547/source/youtube/requiressl/yes/playback_host/r1---sn-nvm-cxbz.googlevideo.com/mm/31%2C29/mn/sn-nvm-cxbz%2Csn-4g5e6ns6/ms/au%2Crdu/mv/m/mvi/0/pl/21/tx/23791272/txs/23791272%2C23791946/hfr/all/as/fmp4_audio_clear%2Cwebm_audio_clear%2Cwebm2_audio_clear%2Cfmp4_sd_hd_clear%2Cwebm2_sd_hd_clear/initcwndbps/1011250/vprv/1/mt/1581947403/fvip/1/keepalive/yes/fexp/23842630/itag/0/sparams/expire%2Cei%2Cip%2Cid%2Csource%2Crequiressl%2Ctx%2Ctxs%2Chfr%2Cas%2Cvprv%2Citag/sig/ALgxI2wwRgIhAPW33gBgjTnJZRN3NHldZNRij3VBrasQ9WF7LICVXE5QAiEAv3FTUbTAWfhE0fPPVK8C-OcuhMeBzrts978H3Ekps4I%3D/lsparams/playback_host%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps/lsig/AHylml4wRQIgEJkWbVfsy1ESZtKyAr9MvpRgc-8P2dxDrOJbmSiEFFkCIQDsybTcSccQLNkjA-ftkTJcgtLnAOchiUTT0knBmJiyrQ%3D%3D'
[dashsegments] Total fragments: 9
[download] Destination: Lethal Running Beta Footage-oGMuZiG6JUc.f140.m4a
[download] 100% of 1.21MiB in 00:10
[ffmpeg] Merging formats into "Lethal Running Beta Footage-oGMuZiG6JUc.mp4"
[debug] ffmpeg command line: /usr/local/bin/ffmpeg -y -loglevel 'repeat+info' -i 'file:Lethal Running Beta Footage-oGMuZiG6JUc.f136.mp4' -i 'file:Lethal Running Beta Footage-oGMuZiG6JUc.f140.m4a' -c copy -map '0:v:0' -map '1:a:0' 'file:Lethal Running Beta Footage-oGMuZiG6JUc.temp.mp4'
Deleting original file Lethal Running Beta Footage-oGMuZiG6JUc.f136.mp4 (pass -k to keep)
Deleting original file Lethal Running Beta Footage-oGMuZiG6JUc.f140.m4a (pass -k to keep)

Description

When downloading a DASH Video from YouTube the final file will end up with ugly artefacts in the first few (about 10) seconds. Downloaded file from the example above ends up like this (left YT, right downloaded): https://www.dropbox.com/s/5rbe8hr5e7ck7lj/oGMuZiG6JUc.png?dl=0

I tried using --hls-prefer-ffmpeg as mentioned here: #14748 - but with no success (same result). Other tickets with a similar issue are closed without a solution so far.

[dstftw]

Outdated ffmpeg.