information about the x264 log

[chros]

I have searched the forum (and tried Google), but I can't find any info about the information that the x264 log contains.
eg:

avis [info]: 1280x544 @ 23.98 fps (239470 frames)
x264 [info]: using cpu capabilities: MMX MMXEXT SSE SSE2 3DNow!
x264 [warning]: VBV maxrate specified, but no bufsize.
mp4 [info]: initial delay 834166 (scale 10000000)
x264 [info]: slice I:2323  Avg QP:19.01  size: 78885a 0:00:00
x264 [info]: slice P:101512 Avg QP:21.38  size: 28261
x264 [info]: slice B:135635 Avg QP:22.36  size:  9179
x264 [info]: mb I  I16..4: 19.1% 75.0%  5.9%
x264 [info]: mb P  I16..4:  6.8% 17.0%  1.1%  P16..4: 36.9% 6.0%  7.8%  0.0%  0.0%    skip:14.4%
x264 [info]: mb B  I16..4:  0.3%  1.0%  0.2%  B16..8: 26.6%  2.0%  4.4%  direct: 4.5%  skip:61.0%
x264 [info]: 8x8 transform  intra:68.8%  inter:73.5%
x264 [info]: direct mvs  spatial:96.3%  temporal:3.7%
x264 [info]: ref P  68.0% 17.8%  6.6%  4.6%  2.9%
x264 [info]: ref B  83.3% 10.7%  2.9%  1.9%  1.2%
x264 [info]: kb/s:3441.8

encoded 239470 frames, 3.55 fps, 3441.84 kb/s

Can somebody explain all the lines or give me a link?

Thanks