Rough notes as I learn how to use youtube-dl and FFmpeg to download and encode high-resolution videos from YouTube.
Note that my use of youtube-dl is experimental, and I mostly rely on it to download my own recordings when I stream and don't have the possibility of recording locally.
youtube-dl, yt-dlp, and similar tools are against YouTube's terms and conditions, and explicitly publishing content showing people how to download using these methods could get you a channel violation—what YouTube calls community strikes—which could eventually lead to the cancellation of your YouTube channel.
youtube-dl \
-f 271+140 \
"https://youtu.be/n9ZW-Vq6pbk"
271 is the code for the webm video format at 2560x1440
140 is the code for the m4a audio format at 128k (44100Hz)
youtube-dl \
-f 271+140 \
--recode-video mp4 \
"https://youtu.be/n9ZW-Vq6pbk"
Note that if your video is not 2560x1440 it will be upsized (if smaller) or downscaled (if bigger). In this case, I'm re-encoding a video that is 2560x1440 respecting its size using h.264 video codec.
ffmpeg -i "my-video.mkv" -vf scale=2560:1440 -c:v libx264 "my-video.mkv.2560x1440.mp4"
youtube-dlyoutube-dl -F "https://youtu.be/XdOrU1rwBP4"
Will return the following:
[youtube] XdOrU1rwBP4: Downloading webpage
[info] Available formats for XdOrU1rwBP4:
format code extension resolution note
249 webm audio only tiny 50k , opus @ 50k (48000Hz), 900.11KiB
250 webm audio only tiny 72k , opus @ 70k (48000Hz), 1.27MiB
251 webm audio only tiny 124k , opus @160k (48000Hz), 2.19MiB
140 m4a audio only tiny 130k , m4a_dash container, mp4a.40.2@128k (44100Hz), 2.36MiB
278 webm 256x144 144p 61k , webm container, vp9, 30fps, video only, 559.52KiB
160 mp4 256x144 144p 71k , avc1.4d400c, 30fps, video only, 469.47KiB
242 webm 426x240 240p 90k , vp9, 30fps, video only, 642.75KiB
243 webm 640x360 360p 142k , vp9, 30fps, video only, 1.00MiB
133 mp4 426x240 240p 171k , avc1.4d4015, 30fps, video only, 942.27KiB
244 webm 854x480 480p 218k , vp9, 30fps, video only, 1.54MiB
134 mp4 640x360 360p 266k , avc1.4d401e, 30fps, video only, 1.65MiB
247 webm 1280x720 720p 360k , vp9, 30fps, video only, 2.99MiB
135 mp4 854x480 480p 386k , avc1.4d401f, 30fps, video only, 2.27MiB
248 webm 1920x1080 1080p 445k , vp9, 30fps, video only, 3.28MiB
136 mp4 1280x720 720p 511k , avc1.64001f, 30fps, video only, 3.86MiB
137 mp4 1920x1080 1080p 687k , avc1.640028, 30fps, video only, 6.62MiB
271 webm 2560x1440 1440p 1276k , vp9, 30fps, video only, 8.59MiB
18 mp4 640x360 360p 184k , avc1.42001E, 30fps, mp4a.40.2@ 96k (44100Hz), 3.37MiB
22 mp4 1280x720 720p 339k , avc1.64001F, 30fps, mp4a.40.2@192k (44100Hz) (best)
From my test, once we download the highest resolution mkv video with youtube-dl we obtain the exact same result by using the --recode-video mp4 option (to auto-convert after downloading that mkv) or recoding to mp4 afterward with FFmpeg (which turns out to be what youtube-dl does behind the scenes).