Maximum and minimum quantizers don't always work

Katie Boundary · 29th September 2020, 20:44

I recently attempted an XviD encode in which I-frames were locked to both a maximum and minimum quantizer of 2, and P-frames were locked to 4.

The encoder accepted only some of my suggestions.

Is this a known bug? Is there a plan to fix it?

blob2500 · 11th April 2024, 13:37

If Adaptive Quantization/VAQ is activated, q-max goes slightly outside the set range (example: 3 -> 5; 5 -> 7). I think it's normal.

Xvid window status has an issue(?) and behaves as if VAQ is not activated and reports max values exactly as set.

In all cases, q-min/max values for I-frames can only be set for 2-pass encoding.

Katie Boundary · 1st May 2024, 05:25

Quote:

Originally Posted by blob2500

If Adaptive Quantization/VAQ is activated

I don't use adaptive quantization. I got tired of always having to look up whether lumi masking or variance masking was the "correct" one to use.

29th September 2020, 20:44	#1 \| Link
Katie Boundary Registered User Join Date: Jan 2015 Posts: 1,080	Maximum and minimum quantizers don't always work I recently attempted an XviD encode in which I-frames were locked to both a maximum and minimum quantizer of 2, and P-frames were locked to 4. The encoder accepted only some of my suggestions. Is this a known bug? Is there a plan to fix it? __________________ I ask unusual questions but always give proper thanks to those who give correct and useful answers.

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11th April 2024, 13:37	#2 \| Link
blob2500 Registered User Join Date: Sep 2007 Location: Italy Posts: 33	If Adaptive Quantization/VAQ is activated, q-max goes slightly outside the set range (example: 3 -> 5; 5 -> 7). I think it's normal. Xvid window status has an issue(?) and behaves as if VAQ is not activated and reports max values exactly as set. In all cases, q-min/max values for I-frames can only be set for 2-pass encoding.