2pass cbr or 1pass vbr for VP6

[MySchizoBuddy]

Looking at Sorenson squeeze Flash video encoder. I'm seeing these options for VP6
2pass cbr, 1pass quality vbr and 1pass vbr

My question is what is the difference between 1pass quality vbr and 1 pass vbr, plus how does it work. I always thought vbr required 2 pass

Plus why would u do cbr with 2 pass anyway.

PS: i didn't make a mistake with flipping 2 pass with 1 pass. those are the options it has along with the usual 1 pass cbr and 2 pass vbr.

[foxyshadis]

2pass cbr actually can be useful, in the specialized environments you can get non-realtime cbr done. You can still look forward 10-20 frames to see how to best encode each frame for the smoothest quality, although naturally it's not going to be remotely comprable to vbr.

1-pass quality is just an unbounded-bitrate rough quality level, like x264's crf or xvid's cq mode. If you set different videos to the same value, they'll all come out looking about the same quality but have wildly different bitrates. 1-pass vbr is the same as most other codecs' 1-pass abr/vbr/bitrate mode.

[MySchizoBuddy]

which option do i use for web delivery.