youtube-dl
's idea of best is not perfect. Take this example for instance :
pi@rpi-lounge:~ $ youtube-dl -F https://youtu.be/Xj3gU3jACe8
[youtube] Xj3gU3jACe8: Downloading webpage
[info] Available formats for Xj3gU3jACe8:
format code extension resolution note
249 webm audio only tiny 55k , opus @ 50k (48000Hz), 1.11MiB
250 webm audio only tiny 74k , opus @ 70k (48000Hz), 1.47MiB
140 m4a audio only tiny 130k , m4a_dash container, mp4a.40.2@128k (44100Hz), 2.92MiB
251 webm audio only tiny 143k , opus @160k (48000Hz), 2.89MiB
394 mp4 256x144 144p 81k , av01.0.00M.08, 25fps, video only, 1.54MiB
278 webm 256x144 144p 99k , webm container, vp9, 25fps, video only, 2.14MiB
160 mp4 256x144 144p 110k , avc1.4d400c, 25fps, video only, 2.38MiB
395 mp4 426x240 240p 184k , av01.0.00M.08, 25fps, video only, 3.39MiB
242 webm 426x240 240p 230k , vp9, 25fps, video only, 4.90MiB
133 mp4 426x240 240p 245k , avc1.4d4015, 25fps, video only, 5.19MiB
396 mp4 640x360 360p 395k , av01.0.01M.08, 25fps, video only, 7.20MiB
243 webm 640x360 360p 418k , vp9, 25fps, video only, 9.03MiB
134 mp4 640x360 360p 633k , avc1.4d401e, 25fps, video only, 13.61MiB
397 mp4 854x480 480p 712k , av01.0.04M.08, 25fps, video only, 13.13MiB
244 webm 854x480 480p 774k , vp9, 25fps, video only, 16.75MiB
135 mp4 854x480 480p 1160k , avc1.4d401e, 25fps, video only, 25.45MiB
398 mp4 1280x720 720p 1456k , av01.0.05M.08, 25fps, video only, 26.20MiB
247 webm 1280x720 720p 1539k , vp9, 25fps, video only, 33.49MiB
136 mp4 1280x720 720p 2316k , avc1.4d401f, 25fps, video only, 50.46MiB
399 mp4 1920x1080 1080p 2492k , av01.0.08M.08, 25fps, video only, 45.96MiB
248 webm 1920x1080 1080p 2700k , vp9, 25fps, video only, 58.80MiB
137 mp4 1920x1080 1080p 4337k , avc1.640028, 25fps, video only, 91.16MiB
400 mp4 2560x1440 1440p 7468k , av01.0.12M.08, 25fps, video only, 143.60MiB
271 webm 2560x1440 1440p 8993k , vp9, 25fps, video only, 189.90MiB
401 mp4 3840x2160 2160p 14110k , av01.0.12M.08, 25fps, video only, 278.39MiB
313 webm 3840x2160 2160p 18006k , vp9, 25fps, video only, 387.17MiB
18 mp4 640x360 360p 734k , avc1.42001E, 25fps, mp4a.40.2@ 96k (44100Hz), 16.55MiB (best)
The following command:
youtube-dl -f 137+251 https://youtu.be/Xj3gU3jACe8
produces far better results than this usage:
youtube-dl -f 18 https://youtu.be/Xj3gU3jACe8 (marked as best)
There seems to be further bugs as trying to specify the height filters to limit to 1080p doesn't work. It still downloads the 4k variant (which notably is not that marked as best either)
youtube-dl -f "bestvideo[height<=1080,ext=mp4]+bestaudio[ext=m4a]" https://youtu.be/Xj3gU3jACe8
pi@rpi-lounge:~ $ youtube-dl --version
2020.06.16.1
man
page: "youtube-dl now defaults to downloading the highest available quality as reported by YouTube, which will be 1080p or 720p in some cases." – Jos Jun 21 '14 at 10:08-f best
option. – Gabriel Staples Nov 29 '18 at 17:50