Decoder crash for MC 7.1+4 at 128kbps decoding to mono/stereo in ivas_ls_setup_conversion_process_mdct_param_mc_fx()

Basic info

• Float reference:
  • Encoder (float): db364042
  • Decoder (float): db364042
• Fixed point:
  • Decoder (fixed): c7a85855

Bug description

Decoding a Multichannel 7.1+4 bitstream encoded at 128kbps triggers an assert in the decoder:

Assertion failed: (0), function L_shl, file basop32.c, line 2332.

Ways to reproduce

Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-1797

./IVAS_dec mono 48 bit out.wav

This crash occurs also for stereo output, and also for FER/JBM conditions.