"137" is a specific used in tools like youtube-dl and yt-dlp to identify a particular video stream on YouTube. Key Features of Format 137: Resolution: 1080p ( Container: MP4. Codec: H.264 (avc1).
Video only (no audio), usually running at 30fps (though sometimes 60fps), and encoded with high compatibility for playback on most devices. 137 mp4
It is frequently used in commands (e.g., -f 137+140 ) to specifically download the 1080p MP4 version of a video combined with the best available audio (140). "137" is a specific used in tools like