 
 <prompt> Wetin be di highest definition support wey dey listed? Given di previous question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: In November 2008, 720p HD support waka enta. At the time of the 720p launch, the YouTube player change from 4:3 aspect ratio to widescreen 16:9. With this new feature, YouTube begin dey use H.264/MPEG-4 AVC as its default video compression format. In November 2009, 1080p HD support waka enta. In July 2010, YouTube announce say dem don launch range of videos for 4K format, wey allow resolution of up to 4096×3072 pixels. In June 2015, support for 8K resolution waka enta, with the videos dey play for 7680×4320 pixels. 