Back in march, it was discovered that when you view a video directly on Youtube, you could add a "&fmt=18" to the URL to enable a higher quality, higher resolution stream which is encoded with the H.264 codec.
To make this work in an embedded video, however, you need a slightly different hack. After pasting the embed code into a blog post, adjust the two video URLs (one in a param tag and one as the src parameter in the embed tag) by adding "&ap=%2526fmt%3D18" to the end.
check it out:
the bottom one definitely looks crisper to me. (the still frame is the same; you need to play the videos to see the difference.)
how long have these higher-res videos been hiding on youtube? why wouldn't youtube publicize their existence? ¶