Hello,
I wonder what is the reason for the huge jump in bitrate between 4 & 5?!
It seems to be designed like this,
libAACenc/include/aacenc_lib.h
-----------------------------------------------
VBR_MODE | Approx. Bitrate in kbps for stereo
| AAC-LC | AAC-ELD
----------+---------------+--------------------
VBR_1 | 32 (HE-AACv2) | 48
VBR_2 | 72 (HE-AACv1) | 56
VBR_3 | 112 | 72
VBR_4 | 148 | 148
VBR_5 | 228 | 224
--------------------------------------------
perhaps to accommodate the (superfluous) bandwidth.
libAACenc/src/bandwidth.cpp
static const BANDWIDTH_TAB_VBR bandWidthTableVBR[] = {
{AACENC_BR_MODE_CBR, 0, 0},
{AACENC_BR_MODE_VBR_1, 13000, 13000},
{AACENC_BR_MODE_VBR_2, 13000, 13000},
{AACENC_BR_MODE_VBR_3, 15750, 15750},
{AACENC_BR_MODE_VBR_4, 16500, 16500},
{AACENC_BR_MODE_VBR_5, 19293, 19293},
{AACENC_BR_MODE_SFR, 0, 0},
{AACENC_BR_MODE_FF, 0, 0}
AiZ