--minval switch in MPC encoder

2002-01-10 19:08:38

In the new mppenc-0.90s encoder is a new switch called: "--minval". The help says this about it: "calculation of MinVal (0:dflt, 1:buschmann, 2:klemm)".

On Frank Klemm's website in the News part he says: "Some enhances in the frequency range from 100...400 Hz switched on with --xtreme, --insane or --minval 2, increases bitrate by less than 1%, but increase quality for organ music."

My questions:
1. What is MinVal? What are the enhances Frank talks about?
2. What's the difference between --minval 0, 1 and 2 (besides who developed it)?
3. Minval 2 seems to be used in xtreme and insane profiles. Minval 0 seems to be used in standard profile. What about minval 1, the one developed by Andree Buschmann?

--minval switch in MPC encoder

Reply #1 – 2002-01-12 15:18:23

hi,

the "-minval"-options was hidden in the past. the encoder contains this mode for about 3/4 to 1 year.
the purpose of "minval 2" is to achieve higher compression and quality for the low-quality modes (thumb, radio) and higher quality (and bitrates) for high-quality modes (xtreme, insane). the encoders' behaviour for standard-mode does not change too much...
it is a psychoacoustic switch which leads to assumption of fully tonal signals (higher SMR needed) at lower frequencies -- especially in the lowest subband (up to about 700 Hz). the difference between minval1 and 2 is, that minval2 will calculate the minimum SMRs (therefor called "minVal") from the given NMT/TMN-values instead fo using a predefined table...
btw, the latest 1.7.9-encoders should have used minval2 already.

hope this helps,
andree