Higher Frame Rates

Analogue video is interlaced, there are two fields per frame which works well for CRT screens. If you split the fields into their own frames you can get smoother motion on digital displays.

The following is based on PAL.

Composite image 576i (2 fields) vs 576p (double height) of one field.

The following test videos used VirtualDub2 and were grabbed at lossless quality and then deinterlaced. They have been resized so YouTube will play them at 50 frames per second when set to 720p50 or 1080p50.

Grabbed at 768x576 25 frames per second (some capture cards do 720x576).
Deinterlace Yadif double frame rate.
Resize to 960x720 or 1440x1080 (for YouTube).

Please note that YouTube does compress the video significantly and so the quality seen is much lower than the original.
YouTube will downscale 576i/576p video to 480p25 so resizing to 720p or more maintains the correct frame rate.

This test video of the 1984 John Martin's Christmas Pageant was copied to DVD then deinterlaced based on the DVD rip using Python and ImageMagick and upscaled to 1080p.
The full video in 30fps is at https://www.youtube.com/watch?v=ITNelbJIy6Y&t=900