MPEG Quantization with x.264 AVC +mp4

[Vetal]

Before, I used XviD where I set MPEG Quantization (vs x.264 quantization) in codec settings.

It gave me better for my taste, sharper video on high bitrates.

Now I tried to compress with 264 AVC codec. I used meGUI.
It gives more smooth output that [XviD + x.264 quantization]-alike

How can I get the same sharper video impression with 264 AVC? What and where are the quantization setting there? If you have any info from meGUI or StaxRip it would be greatly appreciated.

Thank you

[Dark Shikari]

There is no such thing as "x264 quantization."

H.264 only allows one type of quantizer: the H.264 quantizer. It is a completely flat quantization curve with absolutely no weirdness to it like the H.263 quantizer in Xvid, which tends to smooth out fine details. It is MPEG quantization.

Note however that H.264 does allow one to use any method of one's choice to achieve the necessary quantization; x264 includes two modes, Deadzone (default) and Trellis. Trellis is "generally" better, but by setting the Deadzone settings to low values and not using trellis, it forces x264 to round up more coefficients, achieving a sharper image (at the cost of more bits). A third method, QNS, is in development.

To improve video sharpness, I'd use AQ (adaptive quantization); the latest MeGUI build of x264 has AQ included automatically, which will drastically reduce blurring in flat and background areas.

[Vetal]

There is no ...


Thank you !!!

[LoRd_MuldeR]

H.264 only allows one type of quantizer: the H.264 quantizer.

What about Custom Quantization Matrices? :confused:

[Dark Shikari]

What about Custom Quantization Matrices? :confused:CQMs don't change the quantization method, they just weight different frequencies differently.

[LoRd_MuldeR]

CQMs don't change the quantization method, they just weight different frequencies differently.
Aren't "H.263" and "MPEG" in Xvid options just different hardcoded quantization matrices?

[Dark Shikari]

Aren't "H.263" and "MPEG" in Xvid options just different hardcoded quantization matrices?I'm *pretty sure* they are two distinctly different methods that are mentioned in the standard itself, but don't quote me on that.

[akupenguin]

"MPEG" specifies a dequantization method, and additionally allows CQMs.
"H.263" specifies both a dequantization method and a matrix; it is not equivalent to any CQM.

[LoRd_MuldeR]

"MPEG" specifies a dequantization method, and additionally allows CQMs.
"H.263" specifies both a dequantization method and a matrix; it is not equivalent to any CQM.

I see. Thanks for clearing that up :)

[Vetal]

There is no such thing as "x264 quantization."


To improve video sharpness, I'd use AQ (adaptive quantization); the latest MeGUI build of x264 has AQ included automatically, which will drastically reduce blurring in flat and background areas.

Just got back to my Video. Tried to find AQ in the meGUI (0.3.0.0). Can't find it. Can't find Video profiles with 'AQ' in it.

Could you point me out where this option might be? I.E. tab/option or command line option.

Sorry, I'm new in x264, just used meGUI guide from http://gillam.chris.googlepages.com/encodingx264videos-apracticalguide8

Thank you

[VEGITA]

Under the zones tab use the "custom commandline options":
--aq-strength 0.5 --aq-sensitivity 13
These are the default values.If this doesn't give the result you are after, increase the strength (it can go up to 1).

[Dark Shikari]

Under the zones tab use the "custom commandline options":
--aq-strength 0.5 --aq-sensitivity 13
These are the default values.If this doesn't give the result you are after, increase the strength (it can go up to 1).More specifically, the sensitivity shouldn't be touched--higher strength moves more bits from sharp/detailed areas such as edges to flat background areas. If the strength is very low or zero, you'll end up with the classic problem of the background being blocky or blurry. If the strength is too high, you might get ringing or blurring on the edges. So 0.5 is the default.

[Vetal]

Under the zones tab use the "custom commandline options":
--aq-strength 0.5 --aq-sensitivity 13
These are the default values.If this doesn't give the result you are after, increase the strength (it can go up to 1).

Thank you very much!

Do you know the reason why it is not among UI options? I read meGUI changelog when been looking for AQ. it was removed from meGUI UI a while ago. Is it causing a problems or incompatibility?

[Dark Shikari]

Thank you very much!

Do you know the reason why it is not among UI options? I read meGUI changelog when been looking for AQ. it was removed from meGUI UI a while ago. Is it causing a problems or incompatibility?The concept of AQ has existed for a long time. The current AQ however is very recently developed (past few weeks), while the previous AQ, developed by Haali, is quite old. The previous AQ remained for a patch for a long time and was never accepted into the main code of x264, resulting in many programs like MeGUI not including options for it. The new AQ will likely reach the main SVN soon, so it won't just be an experimental patch.

[Sharktooth]

Just got back to my Video. Tried to find AQ in the meGUI (0.3.0.0). Can't find it. Can't find Video profiles with 'AQ' in it.

Could you point me out where this option might be? I.E. tab/option or command line option.

Sorry, I'm new in x264, just used meGUI guide from http://gillam.chris.googlepages.com/encodingx264videos-apracticalguide8

Thank you
AQ is ON by default. if you want to change settings follow the VEGITA's instructions.
AQ was removed from the options since the Haali AQ was experimenta, wrongly used by ppl (wrong settings) and even if they didnt need it (thus, causing a massively drop in quality). Also AQ was (and still is) not an OFFICIAL x264 option. When AQ will be committed it will be reintroduced in megui.