Support for 4320p60 / 8K

title,
The adaptive stream is as follows:

{
"itag":272,
"url":"https://r5---sn-npoe7ner.googlevideo.com/videoplayback?expire=1608236718&ei=TmrbX_StM8364-EP2aiVyAY&ip=94.198.43.77&id=o-AFxDb1xUEfU_bkofMhgL0SaNnUGf60hQvJlnMu5viQFM&itag=272&aitags=133%2C134%2C135%2C136%2C160%2C242%2C243%2C244%2C247%2C272%2C278%2C298%2C299%2C302%2C303%2C308%2C315%2C330%2C331%2C332%2C333%2C334%2C335%2C336%2C337%2C394%2C395%2C396%2C397%2C398%2C399&source=youtube&requiressl=yes&mh=XR&mm=31%2C26&mn=sn-npoe7ner%2Csn-i3belnlz&ms=au%2Conr&mv=m&mvi=5&pl=24&initcwndbps=321250&vprv=1&mime=video%2Fwebm&ns=Fqk8atfteNvT4Q1N_6mo5msF&gir=yes&clen=849820003&dur=268.966&lmt=1576096789562597&mt=1608214613&fvip=5&keepalive=yes&c=WEB&txp=5311222&n=9HlmABm6R8Kg_Z6mj&sparams=expire%2Cei%2Cip%2Cid%2Caitags%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cns%2Cgir%2Cclen%2Cdur%2Clmt&sig=AOq0QJ8wRQIgWbVaNbH-ku1MLBnKpYzXc0M7B9YV7VXGtgmhpcBNEcQCIQDYY2uCaOVhdfm42fhjXEYQCqXxgSgEmFw_BfUrZYNnVA%3D%3D&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIgUG6ap635XRkXNE7hStW_yOWeeJcdcz4DW6M2CTcHUr8CIQCy-hLeQgk6qLCQKUzaJhs6BTg3fRc2F6WKcbUrh46rMQ%3D%3D",
"mimeType":"video/webm; codecs="vp9"",
"bitrate":43338259,
"width":7680,
"height":4320,
"initRange":{
"start":"0",
"end":"219"
},
"indexRange":{
"start":"220",
"end":"1162"
},
"lastModified":"1576096789562597",
"contentLength":"849820003",
"quality":"highres",
"fps":60,
"qualityLabel":"4320p60",
"projectionType":"RECTANGULAR",
"averageBitrate":25276652,
"colorInfo":{
"primaries":"COLOR_PRIMARIES_BT709",
"transferCharacteristics":"COLOR_TRANSFER_CHARACTERISTICS_BT709",
"matrixCoefficients":"COLOR_MATRIX_COEFFICIENTS_BT709"
},
"approxDurationMs":"268966"
}

Example URL: https://www.youtube.com/watch?v=RGoPU-OLQHE

Something to note is that 8K videos that are 60fps do not have a 30fps variant.

Start by locating the YouTube extraction path that parses adaptive streams and compare how it handles the supplied itag 272 record. Verify the resulting stream exposes 4320p60, including its VP9, dimensions, bitrate, and 60 fps metadata, while accounting for the note that no 30 fps variant exists.