PLC: Noise-bursts in IGF range

Basic info

• Fixed point:
  • Encoder (fixed): n/a
  • Decoder (fixed): Branch 20250826_branch_release_characterization_testing_main, rev. 7d39c224

Bug description

Decoding a 48 kbit/s Stereo bitstream with PLC causes occasional noise-bursts in the IGF, especially during onsets.

First occurrance of these issues are frame no. 1126 and 1127 (no BFI frames).

Frame no 1126 is the first active frame after a long period of inactive (DTX) frame; the last active frame before this was frame no. 1068, which was a BFI frame.

Ways to reproduce

Box folder: ...\_EXTERNAL_IVAS_CHAR_MC\issues\basop-issue-1997 (the folder contains also the bitstreams without any errors)

IVAS_dec stereo 48 20ms_aligned_files_concatenated.ivas_processed.192 out.wav