Parkour, Cops, and Donuts - 4k Ultra HD video
Adam Rifkin stashed this in 4k
Just a comment, it's far easier to make a good gif with very high resolution source.
Video compression creates artifacts that ruins the power of gif optimization algorithms.
Conclusion, if you wanna gif a video always chose the highest resolution if you can, because:
1 - the gif will look better
2 - the gif-optimization will be more effective