$ youtube-dl --list-formats https://www.youtube.com/watch?v=0R0T0mQmx7I
[youtube] 0R0T0mQmx7I: Downloading webpage
[youtube] 0R0T0mQmx7I: Downloading video info webpage
[youtube] 0R0T0mQmx7I: Extracting video information
[youtube] 0R0T0mQmx7I: Downloading MPD manifest
[info] Available formats for 0R0T0mQmx7I:
format code  extension  resolution note
140          m4a        audio only DASH audio  144k , m4a_dash container, mp4a.40.2@128k
160          mp4        256x144    144p  124k , avc1.42c00b, 30fps, video only
133          mp4        426x240    240p  258k , avc1.4d4015, 30fps, video only
134          mp4        640x360    360p  646k , avc1.4d401e, 30fps, video only
135          mp4        854x480    480p 1171k , avc1.4d401f, 30fps, video only
136          mp4        1280x720   720p 2326k , avc1.4d401f, 30fps, video only (best)

$ ffmpeg -i $(youtube-dl -f 136 -g  https://www.youtube.com/watch?v=0R0T0mQmx7I) -i $(youtube-dl -f 140 -g https://www.youtube.com/watch?v=0R0T0mQmx7I) -c:v copy -c:a aac -strict experimental -t 00:02:00 output.mp4