It appears that some time over the weekend, YouTube began experimenting with 3D videos. According Youtube "developer working on the stereoscopic player as a 20% project". "It’s currently very early, hence the silly bugs like swapping the eyes for the anaglyph modes."

The parameters to view such a video are:

• yt3d:enable=true Enables the view mode. (obviously you’ve already discovered this)
• yt3d:aspect=3:4 Sets the aspect of the encoded video.
• yt3d:swap=true Swaps the left and right sources. You may need to add this to videos when the player with fixed anaglyph modes ships. Apologies for the inconvineince.
• yt3d:left=0_0.1_0.5_0.9 and yt3d:right=0.5_0.1_1_0.9 These tags are very provisional and most useful for fixing up old videos. They set the source area for each eye as pairs of coordinates x1_y1_x2_y2. The scale of these coordinates is 0,0 for the the top left down to 1,1 for the bottom right.

If you want to experience the 3D videos, here’s the link @ youtube.

[VIA]