BASOP encoder: audible differences in noise signal in OSBA at 48 kbps

Basic info

• Float reference:
  • Encoder (float):d11999bb (ivas-float-update)
  • Decoder (float):d11999bb
• Fixed point:
  • Encoder (fixed):a43b5c15

Bug description

Noise sounds audibly different in the OSBA LTV with 1 ISM and FOA. The spectrum of the difference signal shows that high frequencies are most strongly affected. Shown is the W channel of the EXT output with the float and BASOP encoders and the difference between these signals from top to bottom.

There may be a connection to #1412 (closed) as OSBA has exactly the same processing as SBA at this bitrate.

Ways to reproduce

This is the command line. The two signals compared above are generated with the float and BASOP encoders and the float decoder.

./IVAS_cod -ism_sba 1 1 ../ivas-pc-testfiles/ltv48_OSBA_4ISM_FOA_ISM1.csv 48000 16 ../ivas-pc-testfiles/ltv16_OSBA_1ISM_FOA.wav bit_fx && ivas-float-update/IVAS_dec EXT 16 bit_fx dec_fx.wav