SWB unstable for Stereo at 16.4 kbps

Basic info

• Float reference:
  • Encoder (float): fbeb5ef8 (Mon Dec 16 08:18:57 2024)
  • Decoder (float): fbeb5ef8 (Mon Dec 16 08:18:57 2024)
• Fixed point:
  • Encoder (fixed): d5b43b02 (Mon Jan 27 04:50:52 2025)

Bug description

The SWB region is unstable and sounds spatially wider than the reference float. The left/right energy seems wrong, e.g. at 1:54.90

Float:

BASOP

Ways to reproduce

Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-1231

../IVAS_cod.exe -dtx -max_band SWB  -stereo 16400 48 20ms_aligned_files_concatenated.wav 20ms_aligned_files_concatenated.ivas.192
../IVAS_dec.exe STEREO 48 20ms_aligned_files_concatenated.ivas.192 20ms_aligned_files_concatenated.ivas.wav