Decoder crash for Stereo at 48/64 kbps mono decoding in IMDCT_ivas_fx()

Basic info

• Float reference:
  • Encoder (float): e15ad0ad
  • Decoder (float):
• Fixed point:
  • Encoder (fixed):
  • Decoder (fixed): d4fd91a6

Bug description

The decoder crashes with an assert:

Ways to reproduce

Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-1342

./IVAS_cod_flt_ref -stereo -max_band FB 48000 48 am1aa1s07_48.10dB.wav bit
./IVAS_dec_fx mono 48 bit out.wav

The crash also occurs for 64kbps for decoding to any output sampling rate (16/32/48). Also occurs conditions if the uploaded error pattern is applied:

eid-xor -vbr -fer bit stereo-mixed-music.am1aa1s07_ep.192 bit_err