Youtube-dl can't merge VP9+Opus youtube videos

[dkoao]

Checklist

• I'm reporting a broken site support
• I've verified that I'm running youtube-dl version 2021.01.24.1
• 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 issues including closed ones

Verbose log

youtube-dl -v --abort-on-unavailable-fragment -f (bestvideo[vcodec=vp9])+(bestaudio[acodec=opus]) https://youtu.be/g6zva0stnOY --no-continue

[debug] System config: []                                                          
[debug] User config: []                                                            
[debug] Custom config: []                                                          
[debug] Command-line args: ['-v', '--abort-on-unavailable-fragment', '-f', '(bestvideo[vcodec=vp9])+(bestaudio[acodec=opus])', 'https://youtu.be/g6zva0stnOY', '--no-continue']   
                                                                       
[debug] Encodings: locale UTF-8, fs utf-8, out utf-8, pref UTF-8  
                 
[debug] youtube-dl version 2021.01.24.1          
                                  
[debug] Python version 3.8.7 (CPython) - Linux-5.10.11-0-lts-x86_64-with           

[debug] exe versions: ffmpeg 4.3.1, ffprobe 4.3.1                                  

[debug] Proxy map: {}                                                              
[youtube] g6zva0stnOY: Downloading webpage                                         
[youtube] g6zva0stnOY: Downloading MPD manifest                                    
[debug] Invoking downloader on [REDACTED]

[dashsegments] Total fragments: 280                                                
[download] Destination: المحاضرة الثانية _ الثرموداينمك _ الجزء الثاني 2021-g6zva0stnOY.f302.webm                                                                     
[download] 100% of 417.83MiB in 24:16                                              
[debug] Invoking downloader on [REDACTED]
[dashsegments] Total fragments: 157
[download] Destination: المحاضرة الثانية _ الثرموداينمك _ الجزء الثاني 2021-g6zva0stnOY.f251.webm
[download] 100% of 22.60MiB in 00:36
[ffmpeg] Merging formats into "المحاضرة الثانية _ الثرموداينمك _ الجزء الثاني 2021-g6zva0stnOY.webm"
[debug] ffmpeg command line: ffmpeg -y -loglevel repeat+info -i 'file:المحاضرة الثانية _ الثرموداينمك _ الجزء الثاني 2021-g6zva0stnOY.f302.webm' -i 'file:المحاضرة الثانية _ الثرموداينمك _ الجزء الثاني 2021-g6zva0stnOY.f251.webm' -c copy -map 0:v:0 -map 1:a:0 'file:المحاضرة الثانية _ الثرموداينمك _ الجزء الثاني 2021-g6zva0stnOY.temp.webm'
ERROR: Conversion failed!
Traceback (most recent call last):
  File "/usr/lib/python3.8/site-packages/youtube_dl/YoutubeDL.py", line 2102, in post_process
    files_to_delete, info = pp.run(info)
  File "/usr/lib/python3.8/site-packages/youtube_dl/postprocessor/ffmpeg.py", line 523, in run
    self.run_ffmpeg_multiple_files(info['__files_to_merge'], temp_filename, args)
  File "/usr/lib/python3.8/site-packages/youtube_dl/postprocessor/ffmpeg.py", line 235, in run_ffmpeg_multiple_files
    raise FFmpegPostProcessorError(msg)
youtube_dl.postprocessor.ffmpeg.FFmpegPostProcessorError: Conversion failed!

FFmpeg gives me the following error when I run the command mentioned in the above output manually:

[webm @ 0x7fe94ccf40c0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 5620 >= 5600 av_interleaved_write_frame(): Invalid argument

I've tried to re-download it multiple times and the issue persists. Other videos can be merged fine, so it seems like this is a problem with this particular video.

[anton-khimich]

Hi, I can confirm that there is no problem with this specific video, as I ran the command with no issues using Python 2.7.12, ffmpeg 2.8.17, and ffprobe 2.8.17. I'll try to reproduce the issue on a system with closer specifications to yours.

Quick update: I was able to reproduce the error on a different system with both Python 2.7.16 and 3.8.7, and ffmpeg, ffprobe 4.1.6-1. I'm going to try again with the same version of ffmpeg as I used before to see whether the ffmpeg version is the cause of this.

[anton-khimich]

I was unable to reproduce the issue on a different system with ffmpeg 2.8.17, leading me to believe the issue lies somewhere with the version differences.

[adrianheine]

So this is is probably an issue in ffmpeg >= 3?

[anton-khimich]

Potentially. I sort of put this off hoping others with different versions of ffmpeg could test this so we could track down which version was the earliest where this doesn't work.

[chocmake]

Experienced this conversion failure error on youtube-dl 2021.03.03 (latest) with ffmpeg 2020-08-31 (last build from Zeranoe) and Python 3.4.4 on W10.

After downloading a VP9 video stream (303) + Opus audio stream (251) of this. Failed to combine the streams.

ERROR: Conversion failed!
Traceback (most recent call last):
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmpvjygsik_\build\youtube_dl\YoutubeDL.py", line
2102, in post_process
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmpvjygsik_\build\youtube_dl\postprocessor\ffmpeg
.py", line 523, in run
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmpvjygsik_\build\youtube_dl\postprocessor\ffmpeg
.py", line 235, in run_ffmpeg_multiple_files
youtube_dl.postprocessor.ffmpeg.FFmpegPostProcessorError: Conversion failed!

[mechalincoln]

I am experiencing this on and off. It's at random with itags for video 302 and 303 plus audio 251.

Y:\youtube-dl>youtube-dl --cookies cookies.txt --download-archive "deltrons_hqv5vp9.log" -i --add-metadata --embed-thumbnail -o "deltron - Videos/%(title)s - %(id)s.%(ext)s" -f --merge-output-format --format (337/315/313/336/308/271/335/303/248/334/302/247/333/244/332/243/331/242/330/278/305/266/304/264/137/136/135/134/133/160)+(251/bestaudio) -x -k --write-description --write-info-json --cache-dir "Z:\cache" --sleep-interval 4 --max-sleep-interval 9 --verbose --fragment-retries 100 https://www.youtube.com/watch?v=MakTbhIZ5zo
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['--cookies', 'cookies.txt', '--download-archive', 'deltrons_hqv5vp9.log', '-i', '--add-metadata', '--embed-thumbnail', '-o', 'deltron - Videos/%(title)s - %(id)s.%(ext)s', '-f', '--merge-output-format', '--format', '(337/315/313/336/308/271/335/303/248/334/302/247/333/244/332/243/331/242/330/278/305/266/304/264/137/136/135/134/133/160)+(251/bestaudio)', '-x', '-k', '--write-description', '--write-info-json', '--cache-dir', 'Z:\\cache', '--sleep-interval', '4', '--max-sleep-interval', '9', '--verbose', '--fragment-retries', '100', 'https://www.youtube.com/watch?v=MakTbhIZ5zo']
[debug] Encodings: locale cp1252, fs mbcs, out cp437, pref cp1252
[debug] youtube-dl version 2021.04.07
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.19041
[debug] exe versions: ffmpeg 2021-02-16-git-8331eb058d-full_build-www.gyan.dev, ffprobe 2021-02-16-git-8331eb058d-full_build-www.gyan.dev
[debug] Proxy map: {}
[youtube] MakTbhIZ5zo: Downloading webpage
[youtube] MakTbhIZ5zo: Downloading MPD manifest
[info] Writing video description to: deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.description
[info] Writing video description metadata as JSON to: deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.info.json
[youtube] MakTbhIZ5zo: Downloading thumbnail ...
[youtube] MakTbhIZ5zo: Writing thumbnail to: deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.jpg
[debug] Invoking downloader on 'https://manifest.googlevideo.com/api/manifest/dash/expire/1617835103/ei/_99tYIT4BozRigSNySg/ip/2601%3A246%3A100%3Aed%3A1c13%3A81e7%3Ae025%3A2467/id/31a9136e1219e73a/source/youtube/requiressl/yes/playback_host/r1---sn-vgqsrnll.googlevideo.com/mh/Sl/mm/31%2C26/mn/sn-vgqsrnll%2Csn-p5qs7nee/ms/au%2Conr/mv/m/mvi/1/pl/30/hfr/all/ctier/A/as/fmp4_audio_clear%2Cwebm_audio_clear%2Cwebm2_audio_clear%2Cfmp4_sd_hd_clear%2Cwebm2_sd_hd_clear/pfa/5/initcwndbps/1758750/hightc/yes/vprv/1/mt/1617812764/fvip/1/keepalive/yes/fexp/24001373%2C24007246/itag/0/sparams/expire%2Cei%2Cip%2Cid%2Csource%2Crequiressl%2Chfr%2Cctier%2Cas%2Cpfa%2Chightc%2Cvprv%2Citag/sig/AOq0QJ8wRgIhAM04WRMu-r3X4O6DsJ6V2J8EhEBc1EZnC6NQx08Rlb4bAiEAlC9nP_f64mY94XLkXAmKTzG1PNjF1T3Ue3veHGQBP2A%3D/lsparams/playback_host%2Cmh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps/lsig/AG3C_xAwRgIhALeDU48dVP5-Glon7lJJ_nnOU5T075_Mrz9dd3wHctGOAiEAkIeNJb2XKOvXwqcHiJ93i-xH8iFiXUsB1Zkn_4yMAdc%3D'
[download] deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f302.webm has already been downloaded
[download] 100% of 12.23MiB
[debug] Invoking downloader on 'https://r1---sn-vgqsrnll.googlevideo.com/videoplayback?expire=1617835103&ei=_99tYIT4BozRigSNySg&ip=2601%3A246%3A100%3Aed%3A1c13%3A81e7%3Ae025%3A2467&id=o-ANILf1kO3YGr-iUpo36fRs7q3EyY3jax2qz5xBR-Dw99&itag=251&source=youtube&requiressl=yes&mh=Sl&mm=31%2C26&mn=sn-vgqsrnll%2Csn-p5qs7nee&ms=au%2Conr&mv=m&mvi=1&pl=30&ctier=A&pfa=5&initcwndbps=1758750&hightc=yes&vprv=1&mime=audio%2Fwebm&ns=qHuTDgJ0OORuqcfJmG-h-RAF&gir=yes&clen=1524583&otfp=1&dur=86.401&lmt=1564102915084376&mt=1617812764&fvip=1&keepalive=yes&fexp=24001373%2C24007246&c=WEB&n=PFIRoG_6UsFUxCyE&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cctier%2Cpfa%2Chightc%2Cvprv%2Cmime%2Cns%2Cgir%2Cclen%2Cotfp%2Cdur%2Clmt&sig=AOq0QJ8wRQIgD-hS0suqwMkewJsa009Wqe61C3uV8_Fq9PD1eTcO4FACIQDK4KsK8hiuEzp2Vzx6p5dWk0ZgrgJWDVq7b56rXWwlXg%3D%3D&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRAIgK3xBpUIFsgaWXDZMsSyhoCJCB6nAEIrU1PrDwsaD54oCIF1XmHk2bIJiD_zmMwsLBoBtjIgeUTainxWbxD6_Ce_b'
[download] deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f251.webm has already been downloaded
[download] 100% of 1.45MiB
[ffmpeg] Merging formats into "deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.webm"
[debug] ffmpeg command line: ffmpeg -y -loglevel "repeat+info" -i "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f302.webm" -i "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f251.webm" -c copy -map "0:v:0" -map "1:a:0" "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.temp.webm"
ERROR: Conversion failed!
Traceback (most recent call last):
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\YoutubeDL.py", line 2106, in post_process
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\postprocessor\ffmpeg.py", line 523, in run
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\postprocessor\ffmpeg.py", line 235, in run_ffmpeg_multiple_files
youtube_dl.postprocessor.ffmpeg.FFmpegPostProcessorError: Conversion failed!

[debug] ffmpeg command line: ffprobe -show_streams "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.webm"
ERROR: WARNING: unable to obtain file audio codec with ffprobe
Traceback (most recent call last):
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\YoutubeDL.py", line 2106, in post_process
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\postprocessor\ffmpeg.py", line 274, in run
youtube_dl.utils.PostProcessingError: WARNING: unable to obtain file audio codec with ffprobe

[ffmpeg] Adding metadata to 'deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.webm'
ERROR: [WinError 2] The system cannot find the file specified: 'deltron - Videos\\LIGHTSKINJOHN - only - MakTbhIZ5zo.webm'
Traceback (most recent call last):
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\YoutubeDL.py", line 806, in wrapper
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\YoutubeDL.py", line 838, in __extract_info
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\YoutubeDL.py", line 872, in process_ie_result
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\YoutubeDL.py", line 1683, in process_video_result
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\YoutubeDL.py", line 2041, in process_info
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\YoutubeDL.py", line 2106, in post_process
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\postprocessor\ffmpeg.py", line 509, in run
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\postprocessor\ffmpeg.py", line 210, in run_ffmpeg_multiple_files
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp5qwpsrl8\build\youtube_dl\postprocessor\ffmpeg.py", line 210, in <genexpr>
FileNotFoundError: [WinError 2] The system cannot find the file specified: 'deltron - Videos\\LIGHTSKINJOHN - only - MakTbhIZ5zo.webm'


Y:\youtube-dl>

This is the latest version:

Y:\youtube-dl>youtube-dl --version
2021.04.07

[pukkandan]

From some testing, I can confirm this is a ffmpeg issue. 3.0.1 is the last version I've found where this doesnot happen

[mechalincoln]

What would be the best way to contact the ffmpeg team about it/describe the issue?

[Lesmiscore]

ffmpeg provided by Ubuntu's default repository have same problem. btw this should be reported to ffmpeg devs tho

ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Missing argument for option 'v'.
Error splitting the argument list: Invalid argument

Edit: transcoding have worked, while copy doesn't

[mechalincoln]

I joined ffmpeg's mailing list, but they don't want to investigate unless the ffmpeg command used is provided.

> ffmpeg version 4.2.4-1ubuntu0.1 Copyright

I don't see any indication for an issue that can be fixed in FFmpeg, if
you disagree please test current FFmpeg git head and provide the
failing ffmpeg (!) command line together with the complete, uncut
console output if you request support here.

This is frustrating. If any of the youtube-dl devs reads this, please contact ffmpeg since it looks like they're not going to fix this on their end.

Does anyone have the ffmpeg command that youtube-dl would use to merge 302 or 303 + 251?

[Lesmiscore]

@mechalincoln
This will appear if you run with -v flag.

ffmpeg -y -loglevel "repeat+info" -i "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f302.webm" -i "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f251.webm" -c copy -map "0:v:0" -map "1:a:0" "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.temp.webm"

[mechalincoln]

Thank you for the prompt response @nao20010128nao . I will relay this to them.

This was the output:

Y:\youtube-dl>ffmpeg -y -loglevel "repeat+info" -i "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f302.webm" -i "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f251.webm" -c copy -map "0:v:0" -map "1:a:0" "file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.temp.webm"
ffmpeg version 2021-02-16-git-8331eb058d-full_build-www.gyan.dev Copyright (c) 2000-2021 the FFmpeg developers
  built with gcc 10.2.0 (Rev6, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-lzma --enable-libsnappy --enable-zlib --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libdav1d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libglslang --enable-vulkan --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
  libavutil      56. 65.100 / 56. 65.100
  libavcodec     58.123.100 / 58.123.100
  libavformat    58. 67.100 / 58. 67.100
  libavdevice    58. 12.100 / 58. 12.100
  libavfilter     7.107.100 /  7.107.100
  libswscale      5.  8.100 /  5.  8.100
  libswresample   3.  8.100 /  3.  8.100
  libpostproc    55.  8.100 / 55.  8.100
Input #0, matroska,webm, from 'file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f302.webm':
  Metadata:
    encoder         : google/video-file
    http://youtube.com/streaming/otf/durations/112015: Segment-Count: 17
                    : Segment-Durations-Ms: 5339,5338,5339(r=1),5338,5339(r=1),5338,5339(r=1),5338,5339(r=1),5338,5339(r=1),901,
                    :
                    :
  Duration: N/A, start: 0.000000, bitrate: N/A
  Stream #0:0(eng): Video: vp9 (Profile 0), yuv420p(tv, bt709/unknown/unknown), 1280x720, SAR 1:1 DAR 16:9, 59.94 fps, 59.94 tbr, 1k tbn, 1k tbc (default)
Input #1, matroska,webm, from 'file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.f251.webm':
  Metadata:
    encoder         : google/video-file
  Duration: 00:01:26.40, start: -0.007000, bitrate: 141 kb/s
  Stream #1:0(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
Output #0, webm, to 'file:deltron - Videos\LIGHTSKINJOHN - only - MakTbhIZ5zo.temp.webm':
  Metadata:
    http://youtube.com/streaming/otf/durations/112015: Segment-Count: 17
                    : Segment-Durations-Ms: 5339,5338,5339(r=1),5338,5339(r=1),5338,5339(r=1),5338,5339(r=1),5338,5339(r=1),901,
                    :
                    :
    encoder         : Lavf58.67.100
  Stream #0:0(eng): Video: vp9 (Profile 0), yuv420p(tv, bt709/unknown/unknown), 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 59.94 fps, 59.94 tbr, 1k tbn, 1k tbc (default)
  Stream #0:1(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #1:0 -> #0:1 (copy)
Press [q] to stop, [?] for help
[webm @ 000002372e6c47c0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 5355 >= 5339
av_interleaved_write_frame(): Invalid argument
frame=  323 fps=0.0 q=-1.0 Lsize=     906kB time=00:00:05.36 bitrate=1384.3kbits/s speed=61.2x
video:825kB audio:89kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Conversion failed!

Y:\youtube-dl>

[mechalincoln]

One of the developers replied with this:

I can reproduce the issue with the following command:
$ ffmpeg -i LIGHTSKINJOHN\ -\ only-MakTbhIZ5zo.f302.webm -c copy out.webm

The issue is not reproducible with "-ss 6", I don't know if the issue
is in the original
YT source, in the way it is downloaded or in FFmpeg.

[pukkandan]

@mechalincoln Can you give a link to the ffmpeg issue you opened?