Is --ratetol used in 2-pass encodes?

[Biggiesized]

If you're shooting for a particular bit rate, shouldn't --ratetol be as theoretically close to 0 as possible? How much does adjusting this setting have on encoding speed for 1-pass encodes?

[sneaker_ger]

I have not done any tests, but I always thought settings it lower would affect quality in a negative way - not speed.

[Dark Shikari]

ratetol tells x264 to be more aggressive in its ratecontrol. This can generally reduce quality.

x264 will generally get close enough to what you want without messing with ratetol. Unless within 0.1% isn't enough for you.

(Note: ratetol also affects the aggressiveness of VBV.)

[Biggiesized]

Do you know of any circumstances where --ratetol 1.0 brakes VBV for Blu-ray encoding?

[Dark Shikari]

Do you know of any circumstances where --ratetol 1.0 brakes VBV for Blu-ray encoding?Huh? 1.0 is the default, why would setting it "do" anything? I have no idea what you're talking about.

[Biggiesized]

From the mewiki (http://mewiki.project357.com/wiki/X264_Settings#ratetol):

When VBV is activated (ie, you're specified --vbv-* options), this setting also affects VBV aggressiveness. Setting this higher allows VBV to fluctuate more at the risk of possibly violating the VBV settings. For this purpose, the unit of measure is arbitrary.

[Dark Shikari]

From the mewiki:I still have no idea what you're talking about. 1.0 is the default. Do I need to write it in 80-foot high concrete letters?

[Biggiesized]

I understand that 1.0 is the default. It says that adjusting --ratetol may violate the VBV settings. Is there any reason to believe that the default will violate VBV settings?

[sneaker_ger]

If I understand it correctly, it could always happen - even for the default. But it rarely will and if it does happen x264 will warn you. Correct?

[Biggiesized]

I'm glad I'm getting my question across to somebody. That's all I wanted to know. Thanks.

[Dark Shikari]

I understand that 1.0 is the default. It says that adjusting --ratetol may violate the VBV settings. Is there any reason to believe that the default will violate VBV settings?Something always "may" happen. A meteor "may" strike your house right now. But it hasn't yet, and if it happens, you'll know about it. Same with VBV: it "may" happen with any encoder, but if it does, the encoder will tell you about it. At least x264 will.

Stop worrying about hypothetical things that haven't happened yet. I'm not worrying about meteors, so neither should you.

[Biggiesized]

I'm just trying to further understand all of the command line switches. I just wanted clarification of the likelihood of the scenario.