A Dutch developer with the name Gericom on GitHub, and GBATemp has a file online that a Nintendo DS YouTube videos can play, though at this time only for completed. n YouTube url.
Gericom posted the first version Tuesday night on the GBATemp.net-forum. Wednesday night, he put a new version on GitHub, where the yuv2rgb-compression performance is improved. Also, he knew the frame rate to improve from 5 to 6fps, he writes on GBATemp. He could this because there are only 144 pixels in height need to be used, which, in turn, the necessary renderkracht saves.
In the example video is a YouTube video of jacksepticeye on a Nintendo DS Lite play.