MKV thumbnail doesn't show in file manager

[nicolaasjan]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running yt-dlp version 2021.03.24.1
• 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

dlp -v -k -f 247+140 uD4izuDMUQA
[debug] User config file: /home/nico/.config/yt-dlp/config
[debug] User config: ['--list-formats-as-table', '-i', '-o', '/dev/shm/test-dlp/%(title)s.%(ext)s', '-f', 'bestvideo[height<=1080][ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best', '--no-mtime', '--embed-thumbnail', '--force-ipv4', '--external-downloader', 'aria2c', '--external-downloader-args', 'aria2c:-x 10 -s 10 -j 10 -k 1M --log-level=info --file-allocation=none']
[debug] Command-line config: ['-v', '-k', '-f', '247+140', 'uD4izuDMUQA']
[debug] Loading archive file None
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] yt-dlp version 2021.03.24.1 (zip)
[debug] Python version 3.6.9 (CPython 64bit) - Linux-5.4.0-70-generic-x86_64-with-LinuxMint-19.3-tricia
[debug] exe versions: ffmpeg N-101396-ga272f38-Nico-20210306, ffprobe N-101396-ga272f38-Nico-20210306
[debug] Proxy map: {}
[youtube] uD4izuDMUQA: Downloading webpage
[debug] Sort order given by user: 
[debug] Formats sorted by: hasvid, ie_pref, lang, quality, res, fps, vcodec:vp9.2(10), acodec, filesize, fs_approx, tbr, vbr, abr, asr, proto, vext, aext, hasaud, source, id
[info] Downloading format(s) 247+140
[youtube] uD4izuDMUQA: Downloading thumbnail  ...
[youtube] uD4izuDMUQA: Writing thumbnail to: /dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).webp
WARNING: Requested formats are incompatible for merge and will be merged into mkv.
[debug] Invoking downloader on 'https://r3---sn-5hne6nsy.googlevideo.com/videoplayback?expire=1617230848&ei=oKdkYLzFLMOXgQeTp6nACA&ip=<REDACTED>&id=o-AKRq3tiLpUYEdvnJojn6PHlGKaU5PfY9b0iRzX08Nyvl&itag=247&aitags=133%2C134%2C135%2C136%2C137%2C160%2C242%2C243%2C244%2C247%2C248%2C271%2C278%2C313%2C394%2C395%2C396%2C397%2C398%2C399%2C400%2C401&source=youtube&requiressl=yes&mh=D4&mm=31%2C29&mn=sn-5hne6nsy%2Csn-5hnekn7z&ms=au%2Crdu&mv=m&mvi=3&pl=19&initcwndbps=1841250&vprv=1&mime=video%2Fwebm&ns=4k6Nl4Hm5ilsAo3WzwknQOYF&gir=yes&clen=124496967&dur=1760.925&lmt=1606232363837132&mt=1617209085&fvip=3&keepalive=yes&fexp=24001373%2C24007246&c=WEB&txp=5511222&n=_u9Ssskcx_uBxqFzYM&sparams=expire%2Cei%2Cip%2Cid%2Caitags%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cns%2Cgir%2Cclen%2Cdur%2Clmt&sig=AOq0QJ8wRAIgSlRiGuuqPy1zV_szO93sxyMuLfpLgV40D3R8cTSIH8QCIA7xVS44tVpPHlbY5T1vchaC8LN3McNoNaUKm1fY-5lR&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIgFQ6xHMWUlgd7-Thn2dexTj2AXGoUNFgAtVJf2TZwEHwCIQDWEAz3bRLr-BWFBezOf_WYUDvfr9DgKUBk-Fnqipw3RQ%3D%3D'
[download] Destination: /dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).f247.webm
[debug] aria2c command line: aria2c -c --console-log-level=warn --summary-interval=0 --download-result=hide --file-allocation=none -x16 -j16 -s16 --header 'User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3561.0 Safari/537.36' --header 'Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7' --header 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' --header 'Accept-Encoding: gzip, deflate' --header 'Accept-Language: en-us,en;q=0.5' --interface 0.0.0.0 --check-certificate=true --remote-time=false -x 10 -s 10 -j 10 -k 1M --log-level=info --file-allocation=none --dir /dev/shm/test-dlp --out 'TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).f247.webm.part' --auto-file-renaming=false -- 'https://r3---sn-5hne6nsy.googlevideo.com/videoplayback?expire=1617230848&ei=oKdkYLzFLMOXgQeTp6nACA&ip=<REDACTED>&id=o-AKRq3tiLpUYEdvnJojn6PHlGKaU5PfY9b0iRzX08Nyvl&itag=247&aitags=133%2C134%2C135%2C136%2C137%2C160%2C242%2C243%2C244%2C247%2C248%2C271%2C278%2C313%2C394%2C395%2C396%2C397%2C398%2C399%2C400%2C401&source=youtube&requiressl=yes&mh=D4&mm=31%2C29&mn=sn-5hne6nsy%2Csn-5hnekn7z&ms=au%2Crdu&mv=m&mvi=3&pl=19&initcwndbps=1841250&vprv=1&mime=video%2Fwebm&ns=4k6Nl4Hm5ilsAo3WzwknQOYF&gir=yes&clen=124496967&dur=1760.925&lmt=1606232363837132&mt=1617209085&fvip=3&keepalive=yes&fexp=24001373%2C24007246&c=WEB&txp=5511222&n=_u9Ssskcx_uBxqFzYM&sparams=expire%2Cei%2Cip%2Cid%2Caitags%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cns%2Cgir%2Cclen%2Cdur%2Clmt&sig=AOq0QJ8wRAIgSlRiGuuqPy1zV_szO93sxyMuLfpLgV40D3R8cTSIH8QCIA7xVS44tVpPHlbY5T1vchaC8LN3McNoNaUKm1fY-5lR&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIgFQ6xHMWUlgd7-Thn2dexTj2AXGoUNFgAtVJf2TZwEHwCIQDWEAz3bRLr-BWFBezOf_WYUDvfr9DgKUBk-Fnqipw3RQ%3D%3D'
[aria2c] Downloaded 124496967 bytes:2.4MiB]                                    
[download] 100% of 118.73MiB in 00:25
[debug] Invoking downloader on 'https://r3---sn-5hne6nsy.googlevideo.com/videoplayback?expire=1617230848&ei=oKdkYLzFLMOXgQeTp6nACA&ip=<REDACTED>&id=o-AKRq3tiLpUYEdvnJojn6PHlGKaU5PfY9b0iRzX08Nyvl&itag=140&source=youtube&requiressl=yes&mh=D4&mm=31%2C29&mn=sn-5hne6nsy%2Csn-5hnekn7z&ms=au%2Crdu&mv=m&mvi=3&pl=19&initcwndbps=1841250&vprv=1&mime=audio%2Fmp4&ns=4k6Nl4Hm5ilsAo3WzwknQOYF&gir=yes&clen=28500202&dur=1760.978&lmt=1606232177321386&mt=1617209085&fvip=3&keepalive=yes&fexp=24001373%2C24007246&c=WEB&txp=5511222&n=_u9Ssskcx_uBxqFzYM&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cns%2Cgir%2Cclen%2Cdur%2Clmt&sig=AOq0QJ8wRgIhAPvVp5E5NOcDYHEtyRvS1r96kEnVW1AfvyRv-ti3TgQfAiEA68t7ldUVkunPVH2XCzFxMPxXcYHfy8Xg8OPVUJfJS68%3D&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIgFQ6xHMWUlgd7-Thn2dexTj2AXGoUNFgAtVJf2TZwEHwCIQDWEAz3bRLr-BWFBezOf_WYUDvfr9DgKUBk-Fnqipw3RQ%3D%3D'
[download] Destination: /dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).f140.m4a
[debug] aria2c command line: aria2c -c --console-log-level=warn --summary-interval=0 --download-result=hide --file-allocation=none -x16 -j16 -s16 --header 'User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3561.0 Safari/537.36' --header 'Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7' --header 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' --header 'Accept-Encoding: gzip, deflate' --header 'Accept-Language: en-us,en;q=0.5' --interface 0.0.0.0 --check-certificate=true --remote-time=false -x 10 -s 10 -j 10 -k 1M --log-level=info --file-allocation=none --dir /dev/shm/test-dlp --out 'TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).f140.m4a.part' --auto-file-renaming=false -- 'https://r3---sn-5hne6nsy.googlevideo.com/videoplayback?expire=1617230848&ei=oKdkYLzFLMOXgQeTp6nACA&ip=<REDACTED>&id=o-AKRq3tiLpUYEdvnJojn6PHlGKaU5PfY9b0iRzX08Nyvl&itag=140&source=youtube&requiressl=yes&mh=D4&mm=31%2C29&mn=sn-5hne6nsy%2Csn-5hnekn7z&ms=au%2Crdu&mv=m&mvi=3&pl=19&initcwndbps=1841250&vprv=1&mime=audio%2Fmp4&ns=4k6Nl4Hm5ilsAo3WzwknQOYF&gir=yes&clen=28500202&dur=1760.978&lmt=1606232177321386&mt=1617209085&fvip=3&keepalive=yes&fexp=24001373%2C24007246&c=WEB&txp=5511222&n=_u9Ssskcx_uBxqFzYM&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cns%2Cgir%2Cclen%2Cdur%2Clmt&sig=AOq0QJ8wRgIhAPvVp5E5NOcDYHEtyRvS1r96kEnVW1AfvyRv-ti3TgQfAiEA68t7ldUVkunPVH2XCzFxMPxXcYHfy8Xg8OPVUJfJS68%3D&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIgFQ6xHMWUlgd7-Thn2dexTj2AXGoUNFgAtVJf2TZwEHwCIQDWEAz3bRLr-BWFBezOf_WYUDvfr9DgKUBk-Fnqipw3RQ%3D%3D'
[aria2c] Downloaded 28500202 bytes4.0MiB]                                      
[download] 100% of 27.18MiB in 00:07
[Merger] Merging formats into "/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).mkv"
[debug] ffmpeg command line: ffmpeg -y -loglevel repeat+info -i 'file:/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).f247.webm' -i 'file:/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).f140.m4a' -c copy -map 0:v:0 -map 1:a:0 'file:/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).temp.mkv'
[EmbedThumbnail] Converting thumbnail "/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).webp" to JPEG
[debug] ffmpeg command line: ffmpeg -y -loglevel repeat+info -i 'file:/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).webp' -q:v 1 -bsf:v mjpeg2jpeg 'file:/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).jpg'
[debug] ffprobe command line: ffprobe -hide_banner -show_format -show_streams -print_format json 'file:/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).mkv'
[EmbedThumbnail] Adding thumbnail to "/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).mkv"
[debug] ffmpeg command line: ffmpeg -y -loglevel repeat+info -i 'file:/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).mkv' -c copy -map 0 -dn -attach '/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).jpg' -metadata:s:2 mimetype=image/jpeg -metadata:s:2 filename=cover.jpg 'file:/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).temp.mkv'
[SponSkrub] Trying to mark sponsor sections
[debug] sponskrub command line: sponskrub -chapter -- uD4izuDMUQA '/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).mkv' '/dev/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).spons.mkv'
Downloading video sponsor data
Marking the shilling...
frame=    0 fps=0.0 q=-1.0 q=-1.0 size=       1kB time=00:00:00.00 bitrate=10000frame=35555 fps=0.0 q=-1.0 q=-1.0 size=  128512kB time=00:24:42.91 bitrate= 709.frame=42220 fps=0.0 q=-1.0 Lq=-1.0 size=  149708kB time=00:29:20.95 bitrate= 696.4kbits/s speed=3.01e+03x    
Done!
[SponSkrub] Sponsor sections have been marked

Description

According to the --verbose log, the thumbnail gets embedded, but I don't see it in my file manager.

Mp4 videos however do show them.

MediaInfo also shows it's present (Video #2 section):

General
Unique ID                                : 245651801100467027339100028248566541192 (0xB8CED0E2F6EED56394DAB6E6369C2B88)
Complete name                            : /home/nico/Desktop/shm/test-dlp/TIMELAPSE OF THE FUTURE - A Journey to the End of Time (4K).mkv
Format                                   : Matroska
Format version                           : Version 4 / Version 2
File size                                : 146 MiB
Duration                                 : 29 min 20 s
Overall bit rate                         : 696 kb/s
Writing application                      : Lavf58.70.100
Writing library                          : Lavf58.70.100
ErrorDetectionType                       : Per level 1

Video #1
ID                                       : 1
Format                                   : VP9
Codec ID                                 : V_VP9
Duration                                 : 29 min 20 s
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 23.976 (24000/1001) FPS
Color space                              : YUV
Language                                 : English
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Video #2
ID                                       : 3
Format                                   : V_MJPEG
Codec ID                                 : V_MJPEG
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Color space                              : YUV
Default                                  : No
Forced                                   : No
Color range                              : Full
Matrix coefficients                      : BT.470 System B, BT.470 System G
FILENAME                                 : cover.jpg
MIMETYPE                                 : image/jpeg

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : A_AAC-2
Duration                                 : 29 min 20 s
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 44.1 kHz
Frame rate                               : 43.066 FPS (1024 SPF)
Compression mode                         : Lossy
Title                                    : ISO Media file produced by Google Inc.
Language                                 : English
Default                                  : Yes
Forced                                   : No
VENDOR_ID                                : [0][0][0][0]

Menu
00:00:00.000                             : : <sponskrub-sponsor>
00:00:05.000                             : :sponskrub-content
00:28:59.000                             : : <sponskrub-outro>
00:29:20.000                             : :sponskrub-content

Strange thing is however, that when I add the thumbnail manually after that with ffmpeg, it is shown in the file manager...:

ffmpeg -i "input.mkv" -c copy -map 0 -dn -attach "thumbnail.jpg" -metadata:s:t mimetype=image/jpeg -metadata:s:t filename=cover.jpg "output.mkv"

Note that MediaInfo shows almost the same, but with Attachments : cover.jpg added to it under General.

General
Unique ID                                : 255634614763697365989186325176893249871 (0xC0516F99BBA8706F7C603CFB45E3194F)
Complete name                            : /home/nico/Desktop/shm/test-dlp/naamloze map/output.mkv
Format                                   : Matroska
Format version                           : Version 4 / Version 2
File size                                : 146 MiB
Duration                                 : 29 min 20 s
Overall bit rate                         : 697 kb/s
Writing application                      : Lavf58.70.100
Writing library                          : Lavf58.70.100
Cover                                    : Yes
ErrorDetectionType                       : Per level 1
Attachments                              : cover.jpg

Video #1
ID                                       : 1
Format                                   : VP9
Codec ID                                 : V_VP9
Duration                                 : 29 min 20 s
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 23.976 (24000/1001) FPS
Color space                              : YUV
Language                                 : English
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Video #2
ID                                       : 3
Format                                   : V_MJPEG
Codec ID                                 : V_MJPEG
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Color space                              : YUV
Default                                  : No
Forced                                   : No
Color range                              : Full
Matrix coefficients                      : BT.470 System B, BT.470 System G
FILENAME                                 : cover.jpg
MIMETYPE                                 : image/jpeg

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : A_AAC-2
Duration                                 : 29 min 20 s
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 44.1 kHz
Frame rate                               : 43.066 FPS (1024 SPF)
Compression mode                         : Lossy
Title                                    : ISO Media file produced by Google Inc.
Language                                 : English
Default                                  : Yes
Forced                                   : No
VENDOR_ID                                : [0][0][0][0]

Menu
00:00:00.000                             : : <sponskrub-sponsor>
00:00:05.000                             : :sponskrub-content
00:28:59.000                             : : <sponskrub-outro>
00:29:20.000                             : :sponskrub-content

[pukkandan]

sponskrub is removing the attachment. Try opening an issue in https://github.com/faissaloo/SponSkrub