Assert in ivas_omasa_energy_and_ratio_est_fx()

Basic info

• Fixed point: Branch 20250826_branch_release_characterization_testing_main
  • Encoder (fixed): 53e1178c
  • Decoder (fixed): 53e1178c

Bug description

The encoder triggers an assert in ivas_omasa_energy_and_ratio_est_fx() when processing the characterization-test items for P800-19, cat1, -16 LKFS:

#3  0x00007ffff7cb96e2 in __GI___assert_fail (assertion=0x5555559a77f2 "0", file=0x5555559a77e0 "lib_com/basop32.c", line=2340, function=0x5555559a7840 <__PRETTY_FUNCTION__.1> "L_shl") at assert.c:103
#4  0x00005555557fcc9b in L_shl (L_var1=-1075314688, var2=1) at lib_com/basop32.c:2340
#5  0x0000555555917324 in scale_sig32 (x=0x555555a91b40, lg=540, exp0=8) at lib_com/scale_mem_fx.c:308
#6  0x00005555555e3391 in ivas_omasa_energy_and_ratio_est_fx (hOMasa=0x555555a8e7c0, hOmasaData=0x555555a8d7d0, data_fx=0x7fffffff8a80, input_frame=960, nchan_ism=3, q_data=31) at lib_enc/ivas_omasa_enc_fx.c:1433
#7  0x00005555555e0b09 in ivas_omasa_enc_fx (hOMasa=0x555555a8e7c0, hMasa=0x555555a89ed0, hIsmMeta=0x555555a6d408, data_in=0x7fffffff8a80, q_data=31, input_frame=960, nchan_transport=2, nchan_ism=3, ism_mode=ISM_MASA_MODE_PARAM_ONE_OBJ, 
    data_separated_object_fx=0x555555a72690, idx_separated_object=0x7fffffff8a76) at lib_enc/ivas_omasa_enc_fx.c:804
#8  0x000055555559a65b in ivas_enc_fx (st_ivas=0x555555a6d2d0, data=0x555555abdc20, n_samples=4800) at lib_enc/ivas_enc_fx.c:364
#9  0x000055555555ef2f in IVAS_ENC_EncodeFrameToSerial (hIvasEnc=0x555555a6d2a0, inputBuffer=0x555555abdc20, inputBufferSize=4800, outputBitStream=0x7fffffff8c70, numOutBits=0x7fffffff8c6e) at lib_enc/lib_enc_fx.c:1509
#10 0x0000555555559d0c in main (argc=13, argv=0x7fffffffded8) at apps/encoder.c:761

Occurs in frame 900.

Ways to reproduce

Box folder: ...\Box_EXTERNAL_IVAS_CHAR_MC\Issues\basop-issue-1987

IVAS_cod -ism_masa 3 2 cat1_concatenated.wav.0.csv cat1_concatenated.wav.1.csv cat1_concatenated.wav.2.csv cat1_concatenated.wav.met 64000 48 cat1_concatenated.wav out.192