Userscripts.org

I noticed on some videos "Unknown Format 44 itag=44" appears (example: http://www.youtube.com/watch?v=z-DUAS_ndQg). I believe this is the stddef (480p) WebM version of the video. Which would make sense since 43 is lowdef WebM, and 45 is highdef WebM.

yeah it is 480p WebM.

You can just open the script with an editor and add:
44: { itag: 44, quality: 4, description: getTrans("stddef") , format: "WebM", mres: { width: 845, height: 480 }, acodec: "Vorbis", vcodec: "VP8" , arate: 44100, abr: 128000, vbr: 1000000 },
to the source between the entry for the formats 43 and 45 :)

see:
http://en.wikipedia.org/wiki/YouTube#Quality_an...

Thank you very much. :)

EDIT:
Minor cosmetic error, it should be "width: 854,".

If you don't want to edit the file yourself you can download this one already edited.

http://www.mediafire.com/?yiydi29237dua40

And “Unknown Format 46 itag=46” (WebM, 1920×1080). Example: http://www.youtube.com/watch?v=cw44EdcXRQc Thanks!