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

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.

[Evernow]

@Vangelis66

FWIW, as a Windows Vista SP2 32-bit user, I have no access to the patched ffmpeg builds mentioned earlier in this thread (those, as well as the ones recently offered by yt-dlp devs, target Win7+ …).

You have bigger shit to worry about if you’re on Windows Vista. You do realize you’re on an operating system with no security from Microsoft? There should be no reason for you to be on there other than pure incompetence.

[danny-wu]

Hello 😃

We have narrowed down the problematic ffmpeg commit to https://github.com/FFmpeg/FFmpeg/commit/2e6636aa87303d37b112e79f093ca39500f92364

This commit disabled the ability for ffmpeg to correct DTS errors when the encoding is VP9, and the mode is a simple copy.

We are testing some patches right now to see if we can restore DTS correction for VP9 without re-introducing 4313.