Spectral holes observed in signal decoded from fixed point encoded bitstream, SBA input, 16kHz sampling, -26LKFS leveling, at bitrate 13200bps

Basic info

• Float reference:
  • Encoder (float):de0a9fca
  • Decoder (float):de0a9fca
• Fixed point:
  • Encoder (fixed):cd453935
  • Decoder (fixed):cd453935

Bug description

Input format: HOA1/2/3

Sample rate: 16kHz

Signal level: -26LKFS

Encoding bitrate: 13.2kbps

DTX: False

Observations: spectral hole observed between 6-8kHz in the first half of the signal decoded from bitstream produced by fixed point encoder. Following is one example (W channel, input to encoder: dm5aa1s11_HOA3_16_-26.wav). Similar symptoms were also observed in other decoded channels. The fx version sounds obviously not as bright as the fl version.

Ways to reproduce

Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-1207

Command lines: see cmds.txt in Box folder.