Re: Floor1 doubts...
Eldhelrim <[email protected]>
| Newsgroups | gmane.comp.multimedia.ogg.vorbis.general |
|---|---|
| Message-ID | <[email protected]> |
2009/11/11 <[email protected]> > This mostly restates the same idea several different ways that are > equivalent and I'm not sure where you're confused. So let's step back > a second... > > The floor encodes a continuous function and the values of that > function are meant to be used as multipliers/ratios. Linear floor > multiplied by residue gives you a spectrum. > > The floor is encoded on a logarithmic scale (not actually decibels in > fact, but decibels are easy to understand, so the spec discusses this > in terms of decoding the encoded floor to decibels, then doing a > decibel->linear conversion). Unitless decibels are just ratios. 1 == > 0db, 2 == 6dB, 4 = 12dB. The coversion is a simple 20log10(linear). > > Is that helpful? > > Monty > Hm... I think I could summarize better my doubt in this way: Why the greatest value the floor can have, after converting it to linear, is 1 (which would make 20log10(linear) = 0, as linear is 1)? If the floor is the superposition of tonal and noise masks, then, if it's greatest value is 1, or 0 dB, wouldn't it be many mask values that it couldn't represent? (for example, if the masks superposition equals to 10dB...). Again, this is why I thought of the reference level used in the "dB" scale to be dynamic with frequency (the mdct coefficients). _______________________________________________ Vorbis mailing list [email protected] http://lists.xiph.org/mailman/listinfo/vorbis