I'm a really big fan of WavPack lossless, and like to experiment... So I tried setting up some strange tests for the hybrid mode.
First, I hear that hybrid mode sounds much better than most other codecs for transcoding (thanks for all that work, den), but has a distinct noise floor that lowers as the bitrate increases.
So... I WaveGain'd my wave file before I encoded it in WavPack... I used the Strong Noise Shaping to hopefully get the most masked dither noise possible, and here are my findings... The only thing that would keep me from using the hybrid mode is that 320kbps is a bit too high to achieve a sufficiently low noise floor... But I digress. =P
And yes, I know the minimum is 265kbps... I wanted it to try to hit minimum bitrate.
First, here are the values for the original .wav (Jack Johnson - The Horizon Has Been Defeated)
wavpack -n -h -b256 -j0 : -37.75 dB average, -18.52 dB peak
wavpack -n -h -b256 -j1 : -37.78 dB average, -18.25 dB peak
From what I understand, that's pretty bad... Now, if 320 is sufficient, here's what we should be looking for:
wavpack -n -h -b320 -j0 : -41.40 dB average, -24.77 dB peak
wavpack -n -h -b320 -j1 : -44.83 dB average, -27.69 dB peak
So, here come the WaveGain'd (Dither with Strong Noise Shaping) .wavs...
wavpack -n -h -b256 -j0 : -45.61 dB average, -27.26 dB peak
wavpack -n -h -b256 -j1 : -45.66 dB average, -27.65 dB peak
Comes out better than 320kbps... o.O
A few things...
1. I realize that this is WavPack's quantization error that's reported... But that shouldn't be a problem, because the original quantization (dither, actually) is supposed to be masked by its noise shaping... so it shouldn't be a problem. It seems to me that the dither actually focuses the noise in the perfect places that WavPack would have to add it, therefore making WavPack's percieved impact on the sound quality minimal.
2. This really goes under another thread, but... this tells me that WavPack 4, if it had some better-tuned noise selection algorithms (i.e. where to distribute the quantization noise spectrally), it could have some amazing potential.
If you all see anything wrong with my reasoning or method, please lemme know... And if not... This is great news to me. =D