SBA Decoder: Differences for binaural rendered signals at 64 kbit/s

Basic info

  • Float reference:
  • Fixed point:
    • Encoder (fixed): e9c74df8
    • Decoder (fixed): n/a

Bug description

Decoding the SBA LTV bitstream at 64 kbit/s (and also 48 kbit/s) with binaural rendering gives relatively large differences on the noisy signal portion (0:58 - 1:08).

Diff BASOP - Float:

Bildschirmfoto 2025-04-24 um 21.57.59.png

Looking at the difference signal with EXT output, the diff is much smaller than with binaural rendering. Also, the diff signal get significantly smaller starting at 96 kbit/s, where the Fastconv binaural renderer is used. In my eyes this indicates a precision problem with the parametric binaural renderer.

Bitstream (zipped):

ltv48_HOA3_64kbps.192.zip

Ways to reproduce

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

IVAS_dec binaural 48 ltv48_HOA3_64kbps.192 out.wav