av1+opus are reported incompatible and merged into mkv

[mikhaelkh]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2019.11.28
• 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

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://youtu.be/Zlmswo0S0e0', '-F']
[debug] Encodings: locale cp1251, fs mbcs, out cp1251, pref cp1251
[debug] youtube-dl version 2019.11.28
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.14393
[debug] exe versions: ffmpeg git-2019-12-19-99f505d, ffprobe git-2019-12-19-99f505d
[debug] Proxy map: {}
[youtube] Zlmswo0S0e0: Downloading webpage
[youtube] Zlmswo0S0e0: Downloading video info webpage
[info] Available formats for Zlmswo0S0e0:
format code  extension  resolution note
249          webm       audio only tiny   58k , opus @ 50k (48000Hz), 11.57MiB
250          webm       audio only tiny   76k , opus @ 70k (48000Hz), 15.05MiB
140          m4a        audio only tiny  132k , m4a_dash container, mp4a.40.2@128k (44100Hz), 29.42MiB
251          webm       audio only tiny  146k , opus @160k (48000Hz), 29.25MiB
394          mp4        256x144    144p   98k , av01.0.00M.08, 24fps, video only, 16.35MiB
278          webm       256x144    144p  104k , webm container, vp9, 24fps, video only, 17.55MiB
160          mp4        256x144    144p  191k , avc1.4d400c, 24fps, video only, 18.31MiB
395          mp4        426x240    240p  205k , av01.0.00M.08, 24fps, video only, 32.10MiB
242          webm       426x240    240p  225k , vp9, 24fps, video only, 36.67MiB
133          mp4        426x240    240p  302k , avc1.4d4015, 24fps, video only, 30.14MiB
396          mp4        640x360    360p  377k , av01.0.01M.08, 24fps, video only, 55.45MiB
243          webm       640x360    360p  410k , vp9, 24fps, video only, 63.67MiB
134          mp4        640x360    360p  602k , avc1.4d401e, 24fps, video only, 53.77MiB
397          mp4        854x480    480p  730k , av01.0.04M.08, 24fps, video only, 92.20MiB
244          webm       854x480    480p  753k , vp9, 24fps, video only, 99.13MiB
135          mp4        854x480    480p  962k , avc1.4d401e, 24fps, video only, 77.90MiB
398          mp4        1280x720   720p 1466k , av01.0.05M.08, 24fps, video only, 174.54MiB
247          webm       1280x720   720p 1537k , vp9, 24fps, video only, 166.94MiB
136          mp4        1280x720   720p 1616k , avc1.4d401f, 24fps, video only, 122.29MiB
399          mp4        1920x1080  1080p 2394k , av01.0.08M.08, 24fps, video only, 300.94MiB
248          webm       1920x1080  1080p 2699k , vp9, 24fps, video only, 368.91MiB
137          mp4        1920x1080  1080p 4386k , avc1.640028, 24fps, video only, 348.47MiB
43           webm       640x360    360p , vp8.0, vorbis@128k, 141.57MiB
18           mp4        640x360    360p  543k , avc1.42001E, mp4a.40.2@ 96k (44100Hz), 123.40MiB
22           mp4        1280x720   720p  667k , avc1.64001F, mp4a.40.2@192k (44100Hz) (best) 

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://youtu.be/Zlmswo0S0e0', '-k', '-f', '399+251']
[debug] Encodings: locale cp1251, fs mbcs, out cp1251, pref cp1251
[debug] youtube-dl version 2019.11.28
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.14393
[debug] exe versions: ffmpeg git-2019-12-19-99f505d, ffprobe git-2019-12-19-99f505d
[debug] Proxy map: {}
[youtube] Zlmswo0S0e0: Downloading webpage
[youtube] Zlmswo0S0e0: Downloading video info webpage
WARNING: Requested formats are incompatible for merge and will be merged into mkv.
[debug] Invoking downloader on '...'
[download] HAZBIN HOTEL (PILOT)-Zlmswo0S0e0.f399.mp4 has already been downloaded

[download] 100% of 300.94MiB
[debug] Invoking downloader on '...'
[download] HAZBIN HOTEL (PILOT)-Zlmswo0S0e0.f251.webm has already been downloaded

[download] 100% of 29.25MiB
[ffmpeg] Merging formats into "HAZBIN HOTEL (PILOT)-Zlmswo0S0e0.mkv"
[debug] ffmpeg command line: ffmpeg -y -loglevel "repeat+info" -i "file:HAZBIN HOTEL (PILOT)-Zlmswo0S0e0.f399.mp4" -i "file:HAZBIN HOTEL (PILOT)-Zlmswo0S0e0.f251.webm" -c copy -map "0:v:0" -map "1:a:0" "file:HAZBIN HOTEL (PILOT)-Zlmswo0S0e0.temp.mkv" 

Description

AV1 video and OPUS audio can be merged into WEBM container.
Instead WARNING: Requested formats are incompatible for merge and will be merged into mkv.

[bitraid]

This is AVC1 (MPEG4 part 10/H.264) not AV1.

[mikhaelkh]

@bitraid, format 399 is AV1:
399 mp4 1920x1080 1080p 2394k , av01.0.08M.08, 24fps, video only, 300.94MiB

[bitraid]

Use --merge-output-format webm

[dstftw]

Merging av1 into webm requires ffmpeg 4.1+.

[mikhaelkh]

@dstftw, merging 399+140 (av1+m4a) into mp4 also requires ffmpeg 4.1+, but it is done by default without --merge-output-format mp4

ffmpeg 4.1 released more than a year ago. So av1+opus will be reported incompatible for merge forever? Or there's a grace period for this reasoning, like 3 or 5 years?

Also I don't see formats 398 and 399 in extractor/youtube.py

[Mithgol]

Note: https://www.webmproject.org/docs/container/ does not permit AV1 in WebM.