Doom9's Forum - View Single Post - New Custom Quantization Matrices - EQM AVC Series. Last update: EQM AVC-HR 2005-08-01

Sharktooth · 18th August 2005, 13:18

Matrices are tuned for a certain compressibility. In regions where the codec assigns less bit, the compressibility is usually higher. So, in static scenes, even if the bitrate gets lower, it doesnt mean the codec is using higher quantizers. It's usually the opposite... However when i made AVC-HR i took into account the possibility to set the bitrate variability from "1" to "inf" and the HR matrix should behave correctly (at least in my tests it proved to do it).
It's all a matter of coefficients scaling... for example if the scaling is too "harsh" it will produce artifacts at lower bitrates (too much difference between quants).

18th August 2005, 13:18	#11 \| Link
Sharktooth Mr. Sandman Join Date: Sep 2003 Location: Haddonfield, IL Posts: 11,768	Matrices are tuned for a certain compressibility. In regions where the codec assigns less bit, the compressibility is usually higher. So, in static scenes, even if the bitrate gets lower, it doesnt mean the codec is using higher quantizers. It's usually the opposite... However when i made AVC-HR i took into account the possibility to set the bitrate variability from "1" to "inf" and the HR matrix should behave correctly (at least in my tests it proved to do it). It's all a matter of coefficients scaling... for example if the scaling is too "harsh" it will produce artifacts at lower bitrates (too much difference between quants). __________________ MPEG-4 ASP Custom Matrices: EQM V1(old), EQM AutoGK Sharpmatrix (aka EQM V2), EQM V3HR (updated 01/10/2004), EQM V3LR, EQM V3ULR (updated 04/02/2005), EQM V3UHR (updated 17/12/2004) and EQM V3EHR (updated 05/10/2004) Info about my ASP matrices. MPEG-4 AVC Custom Matrices: EQM AVC-HR Info about my AVC matrices My x264 builds. Mooo!!! Last edited by Sharktooth; 18th August 2005 at 13:42.