HCenc: what happens to the matrix when AQ=4?

[florinandrei]

I'm running HCenc with AQ=4 and it says it's using the Adaptive matrix, even though I specified Fox1. What's going on? Does it take Fox1 and makes changes to it? Or is it an entirely different matrix?

*MAXBITRATE 9500
*ASPECT 16:9
*PROFILE best
*AUTOGOP 18
*CQ_MAXBITRATE 5.000
*AQ 4
*DC_PREC 10
*INTERLACED
*NOSCD
*MATRIX fox1
*LUMGAIN 2
*PRIORITY normal
*WAIT 1

[blutach]

It's adaptive since you have lumgain on.

Regards

[Irakli]

I'm running HCenc with AQ=4 and it says it's using the Adaptive matrix, even though I specified Fox1. What's going on? Does it take Fox1 and makes changes to it? Or is it an entirely different matrix?

*MAXBITRATE 9500
*ASPECT 16:9
*PROFILE best
*AUTOGOP 18
*CQ_MAXBITRATE 5.000
*AQ 4
*DC_PREC 10
*INTERLACED
*NOSCD
*MATRIX fox1
*LUMGAIN 2
*PRIORITY normal
*WAIT 1


As blutach said, AQ does not change matrix, but shifts bits from complex areas to more 'flat' ones to avoid blurring and ablocking in such areas. Lumgain, on the other hand, does change matrix coefficients throughout the encoding process; in particular, matrix coefficients are lowered in relatively 'dark' scenes in order to avoid bad blocking in such scenes. So, in your case, fox1 matrix is used but its coefficients are lowered sometimes in darker scenes to increase quality.

[fjhdavid]

do you think LUMGAIN should be 1 or even 2 by default? it seems that like AQ which is 2 by default, it doesen't hurt and is almost always better in encoding quality?


am I wrong?

Francois