Suggest ~160kbps VBR setting. Options

[guidryp]

Hi,

Looking at the suggested settings/presets I am dismayed at the lack of a VBR setting that operates at a lower bit-rate.

There is APS standard, which on my music easily averages over 200Kbps. In fact my latest Rush albums are averaging over 220Kbps.

I can see noisy metal taking over 220kbps, but a song like Rush-Nobody's Hero taking 230Kbps?

For me, it calls into question the validity of the VBR model if the answer to lower than 230KBps encoding is to use the ABR/CBR settings.

ABR doesn't seem much better than CBR after watching it encode 90+ % of its samples at the target rate.

Surely a VBR setting can be cooked up that can encode the above track at ~160kbps in VBR and still sound better than 160 ABR.

PS - I want to use this setting in my compact Flash based portable, in my car etc. My max space average is 160Kbps do to the size of the portable memory. But I want the best quality in that space.

Peter

[guidryp]

Originally posted by JohnV
Seems that you didn't understand the SFB21 problem with vbr I was trying to explain. If you use only --lowpass 16, the lower frequencies may still bloat the bitrate because of the SFB21 vbr problem (there still remains few MDCT coefficients over 16kHz which can bloat the bitrate).

-Y affects to the bit allocation of all frequencies (SFBs) by disabling over 16kHz noise shaping.

I had read the theory, but my test result did not hold to it. In theory, theory and practice are the same. In practice, theory and practice are different.

I just repeated my test on a different track with the same result. Not dramatic but still has lowpass 16 doing better than -Y. Perhaps -V3 is affecting things in a way you weren't expecting?

Rush - Mission: -alt-preset standard -V3 -b 96
No Lowpass or Y = 6787 bytes
-Y = 6393
--lowpass 16 = 6351
Both = 6351

I am still concluding that there is insufficient energy with lowpass 16 to trigger the extra bits needed for proper rendering of lower frequencies.

Peter