One Pass VBR

[thebeak40]

Hi. I used search for this but found no answer. It seems obvious though.

If using 1 pass vbr, is a vaf file beneficial? I have been using 1 pass, default TS, and default bicubic values and getting pretty decent image quality.

If anyone can comment on the vaf file or offer improved settings I would really appreciate it.

Also, over at R3Mix they have an area called "useful threads" that is meant to compliment the FAQ section. I wonder if something like this would be of benefit here. I remember reading an excellent thread on one pass VBR here, but I am damned if I can find it again. The titles of the threads are not always very descriptive of their content, and this complicates searching sometimes.

[RoopeT]

If you have the .vaf file and want to get better quality than you got with 1-pass vbr, you can use "the robshot tweaked two pass method" to get the maximal quality (Doom has an guide).

[marie]

ISnt CBR better than 1 pass VBR? As well as faster?

How long does it take you to encode using 1 pass VBR and with TS on and Bicubic resize?

[thebeak40]

Getting about .38 RT on p3733\133 with 384 sdram. Start at 10 pm, done by morning.

DDog uses one pass with ts but I cant find the thread where he lists his tweaks.

I did Shawshank which is 2 hour 20 min on 2 cds, as well as Aliens on 2 cds and the image is very acceptable with only a few failures.
Shawshank is low action and Aliens very dark.

Regular movies, say 1:45min look acceptable to me. Multi-pass is error free but takes all night and day as well.

[marie]

Well i hope DDog reads this post.

I want to know which is better, CBR or 1 pass VBR with his tweaks

[thebeak40]

Hi. The cbr for aliens would have been about 1400. Surely that is too low for decent/consistent quality but I have not used it at less than 2000.

As far as speed goes, cbr and one pass are pretty close.

[markrb]

marie you mispelled his name it's DDogg and not DDog.

Anyway here is my take on CBR vs VBR.

CBR theoretically cannot be any worse then any VBR encode set at the same MAX rate as the CBR rate. What VBR does is choose where to use more bits and where to use less giving you the ability to have a smaller file. CBR uses the same amount of bits regardless of whether it needs it or not. A CBR encode will almost always be larger in filesize then a VBR.
2500 kbits is 2500 kbits regardless of whether it's VBR or CBR.
CBR is faster because it does not need to do much in the way of calculations. It knows how many bits it's going to use regardless of the scene. VBR needs to figure out what is complex and what is not. The more passes the more it gets it right.

Mark