Quantizer Help

[jkuy9]

I have been encoding with XviD for a while now and I get some pretty nice rips however I want to learn more about Quantizer as I have read this can make my rips even better :D

Can someone point me in the direction of decent info? I have had a look but I can't find anything that is actually good. Everything I have read so far is what a quantizer is not what settings are good, etc.

Eg are the default settings of 2, 31, 2, 31 in the XviD Codec ok for all types of video or are there better settings? Also how to do know what do to for the Quantization Matrix? Obviously it is important and it looks complex but I don't know where I can start to learn about it :(

Any help would be great.

Cheers all

[Teegedeck]

You can safely use the quantizers without any restrictions, like provided by the defaults. MPEG quantizers generally look sharper. Don't use modulated quants 'cause they're not standard-compliant. Don't use any custom quantization matrices because until now none of them really yielded better results than the standard MPEG matrix. The only exception is if you max out on a movie. In that case you could try a matrix that removes less details, like the CG-matrix. But ONLY if you really get undersized results with the standard matrices.

Hope this is what you wanted to know.

[jkuy9]

Hi,

Thanks for the information. It is on the right track, but where did you find this information? Is there a site or similar which has information on different quantizer settings?

[Teegedeck]

*grin*

If you look a little bit below my avatar, you'll notice a 'badge' that identifies me as some kind of moderator, so you can expect that I've gathered the information from this site and some personal experience with this codec. :p

[Invariant]

Good day to everyone,
I do not want to make a new topic, so I will post here and I believe that my post will be taken into consideration :)

In case of MPEG quantisation type I know each matrices (intra and inter). But what about h.263 quantization type? Is this a single matrix? Where can I find this matrix elemets values?

[Invariant]

Thanks for attention, but I just found information about h.263 quantisation type: it does not use any matrix, it simply divides DCT coefficients by double quant_scale value, that's it.